Updated November 6, 1996

This bibliography of Optima XL-A applications is arranged by subject categories, then by first author within the subject groups. The eleven subject categories are: Binding Studies and Complexes; General Studies; Glycoproteins and Proteoglycans; Lipoproteins; Miscellaneous Samples (Including Peptides); Nucleic Acids; Proteins: Enzymes; Proteins: Receptors; Proteins: Other Proteins; Synthetic Polymers; Viruses. Some references may appear in more than one category. In addition, each time the bibliography is updated, the added references will appear also in the NEW section on the first page.

Each reference is followed by a brief annotation that summarizes some of the Optima XL-A experimental detail and includes the address of one of the authors. The General Studies category contains references to theory, methods, and instrumentation of interest, which frequently do not include any experimental description.

NEW: The following thirteen recently published references have been added since the

October 1, 1996 bibliography update.

**Boice, J. A., Fairman, R. Structural characterization of the tumor suppressor p16, an ankyrin-like repeat protein. Protein Sci. 5, 1776-1784 (1996)

Optima XL-A, sed. equil., M(r), state of association; recombinant human tumor suppressor p16 monomer-dimer; An-60 Ti, 15, 20, 25 and 35 krpm; 239 and 280 nm, 4deg.C; CD and fluorescence also used; effect of concentration; (Fairman) Div. of Macromolecular Structure, Bristol-Myers Squibb Pharmaceutical Research Inst., P. O. Box 4000, Princeton, NJ 08543-4000

**Cabral, J. H. M., Petosa, C., Sutcliffe, M. J., Raza, S., Byron, O., Poy, F., Marfatia, S. M., Chishti, A. H., Liddington, R. C. Crystal structure of a PDZ domain. Nature 382, 649-652 (1996)

Optima XL-A, sed. equil., K(d), m; recombinant human Dlg protein PDZ-3 dimer; 30 krpm, 220 and 278 nm, 20deg.C; X-ray crystallography also used; Dept. of Biochemistry, NCMH and Chemistry, Univ. of Leicester, Leicester LE1 7RH, UK

**Calvert, R., Kahana, E., Gratzer, W. B. Stability of the dystrophin rod domain fold: evidence for nested repeating units. Biophys. J. 71, 1605-1610 (1996)

Optima XL-A, sed. equil., M; sed. vel., S; recombinant human dystrophin fragments; 24 and 28 krpm, then 42 krpm (s.e.), 42 or 60 krpm (s.v.); 230 and 280 nm, 5 or 10deg.C; CD and PAGE also used; (Gratzer) MRC Muscle and Cell Motility Unit, King's College, 26-29 Drury Lane, London WC2B 5RL, UK

**Colfen, H., Harding, S. E., Boulter, J. M., Watts, A. Hydrodynamic examination of the dimeric cytoplasmic domain of the human erythrocyte anion transporter, band 3. Biophys. J. 71, 1611-1615 (1996)

Optima XL-A, sed. equil., K(d), M(w); sed. vel., S; human erythrocyte band 3 protein cytoplasmic domain; 10 krpm (s.e.); 3, 5, 10, 15 and 40 krpm (s.v.); 280 nm, 20deg.C; Model E with interference optics used to compare sed. equil. data with XL-A; gel filtration also used; effect of concentration and speed; (Harding) Natl. Centre for Macromolecular Hydrodynamics, Univ. of Nottingham, Sutton Bonington LE12 5RD, UK

**Consalvi, V., Chiaraluce, R., Millevoi, S., Pasquo, A., Vecchini, P., Chiancone, E., Scandurra, R. Refolding pathway and association intermediates of glutamate dehydrogenase from the hyperthermophile Pyrococcus furiosus. Eur. J. Biochem. 239, 679-685 (1996)

Optima XL-A, sed. vel., S; Pyrococcus furiosus glutamate dehydrogenase and oligomers; 30 or 40 krpm, 280 nm, 20deg.C; CD, fluorescence, light scattering and SEC also used; Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli', Universita 'La Sapienza', Piazzale Aldo Moro, 5, I-00185 Roma, Italy

**Easa, A. M., Armstrong, H. J., Mitchell, J. R., Hill, S. E., Harding, S. E., Taylor, A. J. Maillard induced complexes of bovine serum albuminña dilute solution study. Int. J. Biol. Macromol. 18, 297-301 (1996)

Optima XL-A, sed. vel., S, m estimated from S and D (determined by light scattering); bovine serum albumin aggregates; 15-40 krpm, 280 nm, 20deg.C; albumin heated at 95deg.C between 10 and 80 min with and without the presence of xylose; (Hill) Univ. of Nottingham, Dept. of Applied Biochemistry and Food Science, Sutton Bonington Campus, Loughborough, LE12 5RD, UK

**Faix, J., Steinmetz, M., Boves, H., Kammerer, R. A., Lottspeich, F., Mintert, U., Murphy, J., Stock, A., Aebi, U., Gerisch, G. Cortexillins, major determinants of cell shape and size, are actin-bundling proteins with a parallel coiled-coil tail. Cell 86, 631-642 (1996)

Optima XL-A, sed. equil., M(r); sed. vel., S; recombinant Dictyostelium discoideum cortexillin I dimer; 12 krpm (s.e.), 56 krpm (s.v.), 230 nm, 20deg.C; CD and electron microscopy also used; Max-Planck-Institut fur Biochemie D-82152 Martinsried, Federal Republic of Germany

**Kojima, S., Kuriki, Y., Sato, Y., Arisaka, F., Kumagai, I., Takahashi, S., Miura, K. Synthesis of alpha-helix-forming peptides by gene engineering methods and their characterization by circular dichroism spectra measurements. Biochim. Biophys. Acta 1294, 129-137 (1996)

Optima XL-A, sed. equil., M, state of oligomerization; recombinant alpha-helix-forming peptides; An-60 Ti, 20 krpm, 230 nm, 20deg.C; CD and gel filtration also used; state of oligomerization; (Miura) Inst. for Biomolecular Science, Gakushuin Univ., Mejiro, Tokyo 171, Japan

**Kosukegawa, A., Arisaka, F., Takayama, M., Yajima, H., Kaidow, A., Handa, H. Purification and characterization of virus-like particles and pentamers produced by the expression of SV40 capsid proteins in insect cells. Biochim. Biophys. Acta 1290, 37-45 (1996)

Optima XL-A, sed. equil., m; sed. vel., S; recombinant baculovirus-expressed SV40 virus-like particles and capsid protein pentamers; An-60 Ti, 3500 rpm (s.e.), 10, 15, or 40 krpm (s.v.), 20deg.C, 280 nm; electron microscopy also used; (Handa) Faculty of Bioscience and Biotechnology, Tokyo Inst. of Technology, 4259 Nagatsuta-cho, Midori-ku Yokohama 226, Japan

**Mouz, N., Tricot, C., Ebel, C., Petillot, Y., Stalon, V., Dideberg, O. Use of a designed fusion protein dissociates allosteric properties from the dodecameric state of Pseudomonas aeruginosa catabolic ornithine carbamoyltransferase. Proc. Natl. Acad. Sci. 93, 9414-9419 (1996)

Optima XL-A, sed. equil., m; sed. vel., S; recombinant bacterial ornithine carbamoyltransferase; An-60 Ti, 10 krpm (s.e.), 30 krpm (s.v.), 10deg.C; gel filtration and PAGE also used; (Dideberg) Laboratoire de Cristallographie Macromoleculaire, Institut de Biologie Structurale Jean-Pierre EBEL, Commissariat a l'Energie Atomique-Centre National de la Recherche Scientifique, 41 avenue des Martyrs, F-38027 Grenoble Cedex 1, France

**Narhi, L. O., Philo, J. S., Li, T., Zhang, M., Samal, B., Arakawa, T. Induction of alpha-helix in the beta-sheet protein tumor necrosis factor-alpha: thermal and trifluoroethanol-induced denaturation at neutral pH. Biochemistry 35, 11447-11453 (1996)

Optima XL-A, sed. equil., state of association; recombinant human or murine tumor necrosis factor-alpha monomer-trimer; 10, 14 and 20 krpm, 230 or 280 nm, 25deg.C; effect of concentration; CD also used; Amgen Inc., Amgen Center, M/S 14-2-D, Thousand Oaks, CA 91320-1789

**Narhi, L. O., Philo, J. S., Li, T., Zhang, M., Samal, B., Arakawa, T. Induction of alpha-helix in the beta-sheet protein tumor necrosis factor-alpha: acid-induced denaturation. Biochemistry 35, 11454-11460 (1996)

Optima XL-A, sed. vel., D, g(s*), M(r), S; recombinant human or murine tumor necrosis factor-alpha monomer-trimer; 60 krpm, 230 nm, 20deg.C; effect of pH; CD and FTIR also used; Amgen Inc., Amgen Center, M/S 14-2-D, Thousand Oaks, CA 91320-1789

**Truckses, D. M., Somoza, J. R., Prehoda, K. E., Miller, S. C., Markley, J. L. Coupling between trans/cis proline isomerization and protein stability in staphylococcal nuclease. Protein Sci. 5, 1907-1916 (1996)

Optima XL-A, sed. equil., state of association; recombinant bacterial mutant nucleases; 25, 33 and 37 krpm; 280 nm; NMR and X-ray crystallography also used; (Markley) Dept. of Biochemistry, College of Agricultural and Life Sciences, Univ. of Wisconsin-Madison, 420 Henry Mall, Madison, WI 53706

Binding Studies and Complexes

**Arakawa, T., Philo, J., Kenney, W. C. Structure and solubility of interleukin-2 in sodium dodecyl sulfate. Int. J. Pept. Protein Res. 43, 583-587 (1994)

Optima XL-A, sed. vel., S; recombinant interleukin-2ñSDS complexes; 30 & 60 krpm; 215 nm or 280 nm; effect of SDS concentration; Amgen Inc., Amgen Center, Thousand Oaks, CA

**Arakawa, T., Haniu, M., Narhi, L. O., Miller, J. A., Talvenheimo, J., Philo, J. S., Chute, H. T., Matheson, C., Carnahan, J., Louis, J.-C., Yan, Q., Welcher, A. A., Rosenfeld, R. Formation of heterodimers from three neurotrophins, nerve growth factor, neurotrophin-3, and brain-derived neurotrophic factor. J. Biol. Chem. 269, 27833-27839 (1994)

Optima XL-A, sed. equil., m, state of association; neurotrophin-3ñbrain-derived neurotrophic factor heterodimer; 20-48 krpm, effect of conc.; CD also; Amgen Inc., Thousand Oaks, CA 91320-1789

**Balagurumoorthy, P., Sakamoto, H., Lewis, M. S., Zambrano, N., Clore, G. M., Gronenborn, A. M., Appella, E., Harrington, R. E. Four p53 DNA-binding domain peptides bind natural p53-response elements and bend the DNA. Proc. Natl. Acad. Sci. 92, 8591-8595 (1995)

Optima XL-A, sed. equil., binding stoichiometry, K(d); p53 DNA-binding domain peptidesóDNA complexes; 16 krpm, multiwavelength scanning method, 20deg.C; (Harrington) Dept. of Biochemistry, Univ. of Nevada Reno, Reno, NV 89557-0014

**Behlke, J., Ristau, O., Marg, A. Complex formation and crystallization of adrenodoxin-reductase with adrenodoxin. Progress in Colloid & Polymer Science, Vol. 99, pp. 63-68. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A, sed. equil., K(a), m; adrenodoxin-adrenodoxin reductase interaction; 20 and 24 krpm; 378, 415 and 450 nm or 230, 235 and 240 nm; effect of concentration and ionic strength; 10deg.C; Max Delbruck Center for Molecular Medicine, Robert-R^ssle-Strasse 10, 13122 Berlin, Germany

**Brown, P. M., Tagari, P., Rowan, K. R., Yu, V. L., O'Neill, G. P., Middaugh, C. R., Sanyal, G., Ford-Hutchinson, A. W., Nicholson, D. W. Epitope-labeled soluble human interleukin-5 (IL-5) receptors. Affinity cross-link labeling, IL-5 binding, and biological activity. J. Biol. Chem. 270, 29236-29243 (1995)

Optima XL-A, sed. equil., m; recombinant-soluble IL-5 receptor domain and its interleukin-5 complex; An-60 Ti, 16 and 22 krpm, 4deg.C; BIAcore, CD and fluorescence also used; (Nicholson) Dept. of Biochemistry and Molecular Biology, Merck Frosst Centre for Therapeutic Research, P.O. Box 1005, Pointe Claire-Dorval, Quebec H9R 4P8, Canada

**Bubb, M. R., Knutson, J. R., Porter, D. K., Korn, E. D. Actobindin induces the acccumulation of actin dimers that neither nucleate polymerization nor self-associate. J. Biol. Chem. 269, 25592- 25597 (1994)

Optima XL-A, sed. vel., D, S; actobindin-actin interaction; An-60 Ti, 53 krpm, 4deg.C, 290 nm; fluorescence anisotropy also; (Korn) Lab. of Cell Biol., NHLBI, Natl. Institutes of Health, Bethesda, MD 20892

**Dong, F., Gogol, E. P., von Hippel, P. H. The phage T4-coded DNA replication helicase (gp41) forms a hexamer upon activation by nucleoside triphosphate. J. Biol. Chem. 270, 7462-7473 (1995)

Optima XL-A, sed. vel., S; bacteriophage T4 helicase and its GTP-gamma-S or NTP complexes; An-D or An-F, 50 krpm, 280 nm, SEC & electron microscopy also; state of association; (von Hippel) Institute of Molecular Biology and Dept. of Chemistry, Univ. of Oregon, Eugene, OR 97403-1229

**Fiebrig, I., Harding, S. E., Davis, S. S. Sedimentation analysis of potential interactions between mucins and a putative bioadhesive polymer. Progress in Colloid & Polymer Science, Vol. 94, pp. 66-73. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. vel., S; pig gastric mucin-chitosan complex; 2 & 10 krpm, 230 nm; also MSE Centriscan & LS; (Fiebrig) National Centre for Macromolecular Hydrodynamics, School of Agriculture, Sutton Bonington, Nottingham, England

**Fless, G. M., Snyder, M. L., Furbee, J. W., Jr., Garcia-Hedo, M.-T., Mora, R. Subunit composition of lipoprotein(a) protein. Biochemistry 33, 13492-13501 (1994)

Optima XL-A, sed. equil., b.d., M(r); human plasma LDL, lipoprotein(a), reduced and carboxymethylated of apolipoproteins(a) and -(b), and apoB-apo(a) complex; 3-10 krpm, density adjusted with NaBr; GuHCl; (Fless) Dept. of Medicine, Univ. of Chicago, 5841 S. Maryland Ave., Chicago, IL 60637

**Fless, G. M., Furbee, J., Jr., Snyder, M. L., Meredith, S. C. Ligand-induced conformational change of lipoprotein(a). Biochemistry 35, 2289-2298 (1996)

Optima XL-A, sed. equil. in NaBr, M(r), v-bar; sed. vel., D, f/f(0), K(d), R(s), S; human LDL, Lp(a), and Lp(a-)ñ6-aminohexanoic acid complexes; rhesus monkey Lp(a) and its 6-AHA complex; An-60 Ti; 40 krpm (s.v.), 3500 rpm (diff.), 220 or 280 nm; effect of concentration; PAGE also used; Dept. of Medicine, Univ. of Chicago, 5841 S. Maryland Ave., Chicago, IL 60637

**Ghirlando, R., Keown, M. B., Mackay, G. A., Lewis, M. S., Unkeless, J. C., Gould, H. J. Stoichiometry and thermodynamics of the interaction between the Fc fragment of human IgG(1) and its low-affinity receptor Fc(gamma)RIII. Biochemistry 34, 13320-13327 (1995)

Optima XL-A, sed. equil., K(a), M(b), delta C, delta G, delta H, delta S; human IgG(1) fragment-receptor fragment interaction; 16 krpm, 280 nm, effect of temperature 1-28deg.C; LMB-NIDDK, Bldg. 5., Room 210, 5 Center Dr. MSCO540, Bethesda, MD 20892-0540

**Gonzalez, L., Jr., Plecs, J. J., Alber, T. An engineered allosteric switch in leucine-zipper oligomerization. Nat. Struct. Biol. 3, 510-515 (1996)

Optima XL-A, sed. equil., M(r), state of oligomerization; coiled-coil leucine zipper peptides and ligand complexes; 50 krpm, 235 and 220 nm, 5deg.C and 25deg.C; effect of benzene; CD also used; (Alber) Dept. of Molecular and Cell Biology, 229 Stanley Hall, Univ. of California, Berkeley, CA 94720-3206

**Horan, T., Wen, J., Arakawa, T., Liu, N., Brankow, D., Hu, S., Ratzkin, B., Philo, J. S. Binding of neu differentiation factor with the extracellular domain of Her2 and Her3. J. Biol. Chem. 270, 24604-24608 (1995)

Optima XL-A, sed. equil., stoichiometry; new differentiation factor-extracellular domains of Her2 or Her3 interaction; 8 or 12 krpm, 230 or 280 nm; light scattering and PAGE also used; Amgen Inc., Amgen Center, Thousand Oaks, CA 91320

**Horan, T., Wen, J., Narhi, L., Parker, V., Garcia, A., Arakawa, T., Philo, J. Dimerization of the extracellular domain of granulocyte-colony stimulating factor receptor by ligand binding: a monovalent ligand induces 2:2 complexes. Biochemistry 35, 4886-4896 (1996)

Optima XL-A, sed. equil., K, state of association; recombinant granulocyte-colony stimulating factor receptor and its ligand complex; 5800, 7000 and 8000 rpm; 230 or 280 nm; CD and light scattering/SEC also used; (Arakawa) Amgen Inc., Thousand Oaks, CA 91320-1789

**Jacobsen, M. P., Winzor, D. J. Characterization of the interactions of NADH with the dimeric and tetrameric states of methaemoglobin. Biochim. Biophys. Acta 1246, 17-23 (1995)

Optima XL-A, sed. equil., K(A), K(C); binding of NADH to methemoglobin dimers and tetramers; 12-16 krpm, 20deg.C; Centre for Protein Structure, Function and Engineering, Dept. of Biochemistry, Univ. of Queensland, Brisbane, Qld. 4072, Australia

**Johanson, K., Appelbaum, E., Doyle, M., Hensley, P., Zhao, B., Abdel-Meguid, S. S., Young, P., Cook, R., Carr, S., Matico, R., Cusimano, D., Dul, E., Angelichio, M., Brooks, I., Winborne, E., McDonnell, P., Morton, T., Bennett, D., Sokoloski, T., McNulty, D., Rosenberg, M., Chaiken, I. Binding interactions of human interleukin 5 with its receptor alpha subunit. Large scale production, structural, and functional studies of Drosophila-expressed recombinant proteins. J. Biol. Chem. 270, 9459-9471 (1995)

Optima XL-A, sed. equil., m, stoichiometry; a recombinant human interleukin 5, its receptor alpha subunit and complex; 25deg.C; PAGE, size exclusion chromatrography, mass spectrometry, and filtration microcalorimetry also used; (Chaiken) Dept. of Molecular Immunology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406

**Keown, M. B., Ghirlando, R., Young, R. J., Beavil, A. J., Owens, R. J., Perkins, S. J., Sutton, B. J., Gould, H. J. Hydrodynamic studies of a complex between the Fc fragment of human IgE and a soluble fragment of the Fc-epsilon-RI alpha chain. Proc. Natl. Acad. Sci. 92, 1841-1845 (1995) Optima XL-A, sed. equil., M(b); sed. vel., S; recombinant human IgE, its Fc-epsilon-RI receptor fragment, and complex; 11-17 krpm & 18-22 krpm (s.e.); 40 & 50 krpm (s.v.); 280 nm; PAGE also used; (Gould) The Randall Institute, King's College London, 26-29 Drury Lane, London WC2B 5RL, UK

**Kilby, P. M., Primrose, W. U., Roberts, G. C. K. Changes in the structure of bovine phospholipase A(2) upon micelle binding. Biochem. J. 305, 935-944 (1995)

Optima XL-A, sed. equil., m of protein component; beef pancreatic phospholipase A(2)-SDS complexes; 18 or 40 krpm, 280 nm, 20deg.C; effect of D(2)O; Dept. of Biochemistry and Biological NMR Centre, Univ. of Leicester, Adrian Building, University Road, Leicester, LE1 7RH, UK

**Kleinekofort, W., Germeroth, L., van den Broek, J. A., Schubert, D., Michel, H. The light-harvesting complex II (B800/850) from Rhodospirillum molischianum is an octamer. Biochim. Biophys. Acta 1140, 102-104 (1992)

Optima XL-A, sed. equil., M(r),v-bar; light-harvesting complexñdetergent complexes; 9-25 krpm, 373 and 494 nm; LDAO and C(12)E(8) detergents; Inst. Biophysik der JWG-Universitat and MPI fur Biophysik, Frankfurt am Main, Germany

**Kortt, A. A., Malby, R. L., Caldwell, J. B., Gruen, L. C., Ivancic, N., Lawrence, M. C., Howlett, G. J., Webster, R. G., Hudson, P. J., Colman, P. M. Recombinant anti-sialidase single-chain variable fragment antibody. Characterization, formation of dimer and higher-molecular-mass multimers and the solution of the crystal structure of the single-chain variable fragment/sialidase complex. Eur. J. Biochem. 221, 151-157 (1994)

Optima XL-A, sed. equil., m; complexes of tern sialidase with rec single-chain variable fragment antibody monomer and dimer; Airfuge sed. equil. for K(a) determination., SEC & GF also used; (Kortt) CSIRO, Division of Biomolecular Engineering, 343 Royal Parade, Parkville, Victoria 3052, Australia

**Laue, T. M., Senear, D. F., Eaton, S., Ross, J. B. A. 5-Hydroxytryptophan as a new intrinsic probe for investigating protein-DNA interactions by analytical ultracentrifugation. Study of the effect of DNA on self-assembly of the bacteriophage lambda cI repressor. Biochemistry 32, 2469-2472 (1993)

Optima XL-A, sed. equil., M(r) bacteriophage lambda cI repressor-oligonucleotide binding; 10 krpm; (Laue) Dept. of Biochemistry and Molecular Biology, Univ. of New Hampshire, Durham, NH 03824

**Linsdell, H., Toiron, C., Bruix, M., Rivas, G., Menendez, M. Dimerization of A82846B, vancomycin and ristocetin: influence on antibiotic complexation with cell wall model peptides. J. Antibiot. 49, 181-193, (1996)

Optima XL-A, sed. equil., K; glycopeptide antibiotics A82846B, vancomycin and ristocetin and their cell wall model peptide complexes; 40 krpm; 240, 280 and 300 nm; 25deg.C; NMR also used; Instituto "Rocasolano", Serrano 119, Spain

**Lobert, S., Vulevic, B., Correia, J. J. Interaction of vinca alkaloids with tubulin: a comparison of vinblastine, vincristine, and vinorelbine. Biochemistry 35, 6806-6814 (1996)

Optima XL-A, sed. vel., g(s), K; pig brain tubulin interaction with vinblastine, vincristine and vinorelbine; An-60 Ti, 30 or 42 krpm, 280 nm, 5, 25 or 36deg.C; self-association; stopped-flow light scattering and electron microscopy also used; School of Nursing, Univ. of Mississippi Medical Ctr., 2500 N. State St., Jackson, MS 39216

**Lu, M., Blacklow, S. C., Kim, P. S. A trimeric structural domain of the HIV-1 transmembrane glycoprotein. Nature, Struct. Biol. 2, 1075-1082 (1995)

Optima XL-A, sed. equil., M(r), state of oligomerization; recombinant HIV-1 envelope peptide heterodimer complexes; 15 and 18 krpm, 20deg.C, effect of concentration; CD also used; (Kim) Howard Hughes Medical Inst., Whitehead Inst. for Biomedical Research, Dept. of Biology, Massachusetts Inst. of Technology, Cambridge, MA 02142

**Lewis, M. S., Shrager, R. I., Kim, S.-J. Analysis of protein-nucleic acid and protein-protein interactions using multi-wavelength scans from the XL-A analytical ultracentrifuge. Modern Analytical Ultracentrifugation, pp. 94-115. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A, sed. equil.; Drosophila heat shock factor-DNA binding; computer simulation of protein-protein interactions; multiple scans taken betwen 230 nm & 240 nm; BEIP, NCRR, National Institute of Health, Bethesda, MD 20892

**Lewis, M. S., Shrager, R., Kim, S. J. Ultracentrifugal analysis of protein-nucleic acid interactions using multi-wavelength scans. Progress in Colloid & Polymer Science, Vol. 94, pp. 46-53. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil., absorbancy distributions at multiple wavelengths; Drosophila heat shock factor polypeptide, synthetic oligodeoxynucleotide and their interaction; 230-246, 260 & 280 nm; (Lewis) Biomedical Engineering and Instrumentation Program, National Center for Research Resources, Bethesda, MD

**Lin, K., Hwang, P. K., Fletterick, R. J. Mechanism of regulation in yeast glycogen phosphorylase. J. Biol. Chem. 270, 26833-26839 (1995)

Optima XL-A, sed. equil., m, state of oligomerization; recombinant native and mutant glycogen phosphorylases and their activator or inhibitor complexes; 5000 rpm, 280 nm, 25deg.C; PAGE also used; (Fletterick) Dept. of Biochemistry and Biophysics, Univ. of California, San Francisco, CA 94143-0448

**Liu, J., Lester, P., Builder, S., Shire, S. J. Characterization of complex formation by humanized anti-IgE monoclonal antibody and monoclonal human IgE. Biochemistry 34, 10474-10482 (1995)

Optima XL-A, sed. equil., M(w); sed. vel., g(s)*, S; monoclonal IgE, humanized anti-IgE monoclonal antibody and their complexes; 5, 7 and 10 krpm (s.e.), 60 krpm (s.v.), 10deg.C; size exclusion chromatography also used; hydrodynamic models; (Shire) Pharmaceutical Research and Development and Recovery Process Research and Development, Genentech, Inc., South San Francisco, CA 94080

**Lobert, S., Frankfurter, A., Correia, J. J. Binding of vinblastine to phosphocellulose-purified and alpha/beta-class III tubulin: the role of nucleotides and beta-tubulin isotypes. Biochemistry 34, 8050-8060 (1995)

Optima XL-A, sed. vel., g(s), S; binding of vinblastine to tubulin; An-60 Ti, 30 or 42 krpm, 230-280 nm, 5, 24.6 or 35.5deg.C; effect of nucleotides; electron microscopy also used. (Lobert) School of Nursing, Univ. of Mississippi Med. Ctr., 2500 N. State St., Jackson, MS 39216

**Mach, H., Volkin, D. B., Burke, C. J., Middaugh, C. R., Linhardt, R. J., Fromm, J. R., Loganathan, D., Mattsson, L. Nature of the interaction of heparin with acidic fibroblast growth factor. Biochemistry 32, 5480-5489 (1993)

Optima XL-A, sed. equil., effect of various concentrations on m & stoichiometry; acidic fibroblast growth factor-heparin complexes; 5-30 krpm; also surface plasmon resonance & light scattering; (Mach) Dept. of Pharmaceutical Research, Merck Research Laboratories, WP26-331, West Point, PA 19486

**Malchiodi, E. L., Eisenstein, E., Fields, B. A., Ohlendorf, D. H., Schlievert, P. M., Karjalainen, K., Mariuzza, R. A. Superantigen binding to a T cell receptor beta chain of known three-dimensional structure. J. Exp. Med. 182, 1833-1845 (1995)

Optima XL-A, sed. equil., K(d), M; recombinant T-cell receptor beta-chain, bacterial toxin superantigens, and their complexes; An 55, 22-30 krpm, 20-25deg.C; BIAcore also used and K(d)s compared with XL-A data; (Mariuzza) Center for Advanced Research in Biotechnology, 9600 Gudelsky Dr., Rockville, MD 20850

**Mendoza, J. A., Horowitz, P. M. Bound substrate polypeptides can generally stabilize the tetradecameric structure of Cpn60 and induce its reassembly from monomers. J. Biol. Chem. 269, 25963-25965 (1994)

Optima XL-A, sed. vel., S; chaperonin Cpn60-polypeptide substrate complexes state of dissociation; An-60 Ti, 27 krpm; (Horowitz) Dept Biochem., Univ. of Texas Health Science Center, San Antonio, TX 78240-7760

**Mendoza, J. A., Demeler, B., Horowitz, P. M. Alteration of the quaternary structure of cpn60 modulates chaperonin-assisted folding. Implications for the mechanism of chaperonin action. J. Biol. Chem. 269, 2447-2451 (1994)

Optima XL-A, sed. equil. (m detd. but not reported); sed. vel., S; chaperonin 60 and its rhodanese complex in presence of urea; An-60-Ti, 4500 rpm, 27 krpm and 44 krpm; Gastrointestinal Research Laboratory (151M2), Dept. of Veterans Affairs Medical Center and Dept. of Medicine, Univ. of California, San Francisco, CA 94121

**Nagahora, H., Harata, K., Muraki, M., Jigami, Y. Site-directed mutagenesis and sugar-binding properties of the wheat germ agglutinin mutants Tyr73Phe and Phe116Tyr. Eur. J. Biochem. 233, 27-34 (1995)

Optima XL-A, sed. equil., K(a), m; wheat germ agglutinins and binding of N-acetylglucosamine; 16 krpm, 280 nm; (Jigami) Molecular Biology Dept., National Institute of Bioscience and Human Technology, 1-1 Higashi, Tsukuba, Ibaraki, Japan 305

**Olsen, P. H., Esmon, N. L., Esmon, C. T., Laue, T. M. Ca(2+) dependence of the interactions between protein C, thrombin, and the elastase fragment of thrombomodulin. Analysis by ultracentrifugation. Biochemistry 31, 746-754 (1992)

Optima XL-A, sed. vel., f, S; protein C-thrombin-thrombomodulin complex; 60 krpm, 4-hole rotor, double-sector cells, 20-21deg.C; (Laue) Dept. of Biochemistry, Spaulding Life Sciences Building, Univ. of New Hampshire, Durham, NH 03824.

**Olson, M. W., Dallmann, H. G., McHenry, C. S. DnaX complex of Escherichia coli DNA polymerase III holoenzyme. The chi-psi complex functions by increasing the affinity of tau and gamma for delta*delta( to a physiologically relevant range. J. Biol. Chem. 270, 29570-29577 (1995)

Optima XL-A, sed. equil., M; sed. vel., D, S, Stokes' radius; bacterial DNA polymerase III chi-psi heterodimer complex; An-60 Ti, 15-35 krpm (s.e.), 40 krpm (s.v.), 230 and 280 nm, 4deg.C; BIAcore also used; (McHenry) Dept. of Biochemistry, Biophysics and Genetics and Graduate Program in Molecular Biology, Univ. of Colorado Health Sciences Center, Denver, CO 80262

**Pantoliano, M. W., Horlick, R. A., Springer, B. A., Van Dyk, D. E., Tobery, T., Wetmore, D. R., Lear, J. D., Nahapetian, A. T., Bradley, J. D., Sisk, W. P. Multivalent ligand-receptor binding interactions in the fibroblast growth factor system produce a cooperative growth factor and heparin mechanism for receptor dimerization. Biochemistry 33, 10229-10248 (1994)

Optima XL-A, sed. equil., M(w); recombinant fibroblast growth factor receptor and its complexes with FGF and FGF-heparin; isothermal titrating calorimetry also used; (Pantoliano) 3-Dimensional Pharmaceuticals Inc., 3700 Market St., Philadelphia, PA 19104

**Pennica, D., Lam, V. T., Weber, R. F., Kohr, W. J., Basa, L. J., Spellman, M. W., Ashkenazi, A., Shire, S. J., Goeddel, D. V. Biochemical characterization of the extracellular domain of the 75-kilodalton tumor necrosis factor receptor. Biochemistry 32, 3131-3138 (1993)

Optima XL-A, sed. equil., M(r); recombinant human tissue factor-alpha, -beta, receptor, and complexes; 15 krpm, 235 nm; Depts. of Molecular Biology, Protein Chemistry, Medicinal and Analytical Chemistry, Pulmonary Research, and Pharmaceutical Research and Development, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Philo, J., Talvenheimo, J., Wen, J., Rosenfeld, R., Welcher, A., Arakawa, T. Interactions of neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), and the NT-3(BDNF heterodimer with the extracellular domains of the TrkB and TrkC receptors. J. Biol. Chem. 269, 27840-27846 (1994)

Optima XL-A, sed. equil., K(d); neurotrophins-receptors interactions; 10-14 krpm; Amgen Inc., Thousand Oaks, CA 91320-1789

**Philo, J. S., Aoki, K. H., Arakawa, T., Narhi, L. O., Wen, J. Dimerization of the extracellular domain of the erythropoietin (EPO) receptor by EPO: one high-affinity and one low-affinity interaction. Biochemistry 35, 1681-1691 (1996)

Optima XL-A, sed. equil., K(d), M(r); recombinant glycosylated and deglycosylated erythropoietin receptor-erythropoietin interaction; 10, 11, 15 and 18 krpm (also final run at 48 krpm to establish baseline); 230 and 280 nm; light scattering/size exclusion chromatography and titration calorimetry also used; Protein Chemistry Dept., Amgen, Inc., Amgen Ctr., Thousand Oaks, CA 91320

**Philo, J. S., Wen, J., Wypych, J., Schwartz, M. G., Mendiaz, E. A., Langley, K. E. Human stem cell factor dimer forms a complex with two molecules of the extracellular domain of its receptor, Kit. J. Biol. Chem. 271, 6895-6902 (1996)

Optima XL-A, sed. equil., K(d), state of association; recombinant stem cell factor-Kit receptor complex; 8, 11 and 14 krpm; 215, 230 and 280 nm; light scattering/SEC and titration calorimetry also used; (Langley) Amgen Inc., 1840 DeHavilland Dr., Thousand Oaks, CA 91320-1789

**Riley, L. G., Ralston, G. B., Weiss, A. S. Multimer formation as a consequence of separate homodimerization domains: the human c-Jun leucine zipper is a transplantable dimerization module. Protein Eng. 9, 223-230 (1996)

Optima XL-A and Model E with interference optics, sed. equil., M(w) (Da), state of association; c-Jun and c-Fos leucine zipper domain-glutathione transferase fusion proteins; 20 or 18 krpm, 280 and 360 nm, 20deg.C; PAGE and gel filtration also used; (Weiss) Dept. of Biochemistry, Univ. of Sydney, NSW 2006, Australia

**Rivas, G., Tangemann, K., Minton, A. P., Engal, J. Binding of fibrinogen to platelet integrin alpha-IIb-beta-3 in solution as monitored by tracer sedimentation equilibrium. J. Mol. Recognit. 9, 31-38 (1996)

Optima XL-A, tracer sed. equil., K(d); integrin alpha-IIb-beta-3ñfibrinogen binding; 3-10 krpm, 280-290 nm or 495-550 nm, 10deg.C; with and without detergent; electron microscopy also used; Centro de Investigaciones Biologicas, CSIC, Velazquez 144, 28006-Madrid, Spain

**Sackett, D. L. Vinca site agents induce structural changes in tubulin different from and antagonistic to changes induced by colchicine site agents. Biochemistry 34, 7010-7019 (1995)

Optima XL-A, sed. vel., state of association; interaction of vincristine and maytansine with tubulin; No exptl. details; state of association; fluorescence also used; Natl. Inst. of Health, Bldg. 8, Room 2A23, Bethesda, MD 20892

**Sackett, D. L., Kosk-Kosicka, D. The active species of plasma membrane Ca(2+)-ATPase are a dimer and a monomer-calmodulin complex. J. Biol. Chem. 271, 9987-9991 (1996)

Optima XL-A and Model E with Scanner, sed. equil., m, state of oligomerization; erythrocyte membrane Ca(2+)-ATPase dimer and monomer-calmodulin complex; An-60 Ti, 12-15 krpm; 230, 280 and 350 nm, 20 or 25deg.C; (Kosk-Kosicka) Dept. of Anesthesiology/Critical Care Medicine, The Johns Hopkins Univ. School of Medicine, Baltimore, MD 21287

**Saez, C. T., Jansen, G. J., Smith, A., Morgan, W. T. Interaction of histidineñproline-rich glycoprotein with plasminogen: effect of ligands, pH, ionic strength, and chemical modification. Biochemistry 34, 2496-2503 (1995)

Optima XL-A, sed. equil., K(d), M; FITC-plasminogen interaction with histidineñproline-rich glycoprotein; An-60 Ti, 10 krpm & 30-10 krpm, 495 nm; effect of temperature (25-4deg.C); sucrose gradient centrifugation (VTi 80) also used; (Morgan) Univ. of MissouriñKansas City, Division of Biochemistry and Molecular Biology, School of Biological Sciences, Kansas City, Missouri 64110

**Schuck, P. Simultaneous radial and wavelength analysis with the Optima XL-A analytical ultracentrifuge. Progress in Colloid & Polymer Science, Vol. 94, pp. 1-13. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil., extinction profiles, M(r); human erythrocyte band 3 protein, DBDS nonionic detergent and oxyhemoglobin mixtures studied as model systems; 11-12,500 rpm; mathematical analysis described; 4deg.C, 270-340 nm; Institut fur Biophysik der Johann Wolfgang Goethe-Universitat and Max-Planck-Institut fur Biophysik, Frankfurt am Main, FRG

**Schuck, P., Legrum, B., Passow, H., Schubert, D. The influence of two anion-transport inhibitors, 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonate and 4,4'-dibenzoylstilbene-2,2'-disulfonate, on the self-association of erythrocyte band 3 protein. Eur. J. Biochem. 230, 806-812 (1995)

Optima XL-A, sed. equil., state of association; human erythrocyte membrane band 3 protein and its interactions with stilbenedisulfonates; 9-12.5 krpm, 4deg.C, 280 nm; (Schubert) Institut fur Biophysik der J. W. Goethe-Univ. Theodor-Stern-Kai 7, Haus 74, D-60590 Frankfurt am Main, Germany

**Seifert, A., Heinevetter, L., C^lfen, H., Harding, S. E. Characterization of gliadin-galactomannan incubation mixtures by analytical ultracentrifugation. Part I. Sedimentation velocity. Carbohydr. Polym. 28, 325-332 (1995)

Optima XL-A, sed. equil., M(w); wheat gliadin and locust bean galactomannan; Model E and MOM 3170B analytical ultracentrifuge with schlieren optics, S; gliadin, galactomannan and their interaction; 10 and 15 krpm, 220 and 230 nm (XL-A); PAGE also used; German Institute for Human Nutrition, Arthur-Scheunert-Allee 114-116, D-14558 Bergholz-Rehbrucke, Germany

**Stafford, W. F., Liu, S., Prevelige, P. E. New high sensitivity sedimentation methods: application to the analysis of the assembly of bacteriophage P22. Techniques in Protein Chemistry, Vol. 6, pp. 427-434. Edited by J. W. Crabb. San Diego, Academic Press, 1995.

Optima XL-A with both absorption and video-based on-line interference optics, g(s*) vs. s*; bacteriophage P22 coat protein-bisANS dye interaction; Analytical Centrifugation Research Laboratory, Boston Biomedical Research Institute, Boston, MA 02114

**Ward, L. D., Howlett, G. J., Discolo, G., Yasukawa, K., Hammacher, A., Moritz, R. L., Simpson, R. J. High affinity interleukin-6 receptor is a hexameric complex consisting of two molecules each of interleukin-6, interleukin-6 receptor, and gp-130. J. Biol. Chem. 269, 23286-23289 (1994)

Optima XL-A, sed. equil., M; recombinant human interleukin-6, its receptor and IL-6-receptor-gp 130 complex; 12-, 10-, 8- and 6-krpm; BIAcore & SEC also used; (Simpson) Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research, Post Office Royal Melbourne Hospital, Parksville, Victoria 3050, Australia

**Ward, L. D., Hammacher, A., Howlett, G. J., Matthews, J. M., Fabri, L., Moritz, R. L., Nice, E. C., Weinstock, J., Simpson, R. J. Influence of interleukin-6 (IL-6) dimerization on formation of the high affinity hexameric IL-6:receptor complex. J. Biol. Chem. 271, 20138-20144 (1996)

Optima XL-A, sed. equil., M(r); recombinant human interleukin-6 monomer, dimer and their receptor complexes; 8 and 12 krpm, 20deg.C; BIAcore also used; (Simpson) Joint Protein Structure Laboratory, Ludwig Inst. for Cancer Research, P.O. Box 2008, Royal Melbourne Hospital, Victoria, 3050, Australia

**Wilson, T. J., Argaet, V. P., Howlett, G. J., Davidson, B. E. Evidence for two aromatic amino acid-binding sites, one ATP-dependent and the other ATP-independent, in the Escherichia coli regulatory protein TyrR. Mol. Microbiol. 17, 483-492 (1995)

Optima XL-A, sed. equil., K(a), K(d); bacterial regulatory protein TyrR-amino acid ligand binding; An-60 Ti, 8 krpm, 20deg.C, 285 and 293 nm; UV difference spectroscopy also used; (Davidson) Dept. of Biochemistry and Molecular Biology, The Univ. of Melbourne, Parkville, Victoria 3052, Australia

**Wu, M.-L., Morgan, W. T. Thermodynamics of heme-induced conformational changes in hemopexin: role of domain-domain interactions. Protein Sci. 4, 29-34 (1995)

Optima XL-A, sed. equil., K(d); rabbit serum hemopexin domain I-domain II interaction; 15 krpm; 280, 404 or 497 nm; titration calorimetry also used; Division of Molecular Biology and Biochemistry, School of Biological Sciences, Univ. of Missouri-Kansas City, Kansas City, MO 64110

**Wu, Z., Johnson, K. W., Goldstein, B., Choi, Y., Eaton, S. F., Laue, T. M., Ciardelli, T. L. Solution assembly of a soluble, heteromeric, high affinity interleukin-2 receptor complex. J. Biol. Chem. 270, 16039-16044 (1995)

Optima XL-A, interference optics, sed. equil., M(z); sed. vel., g(s*), interleukin-2 receptorñcoiled-coil complexes; 50 krpm; PAGE also; (Wu) Dept. of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH 03755

**Yang, Y. R., Schachman, H. K. A bifunctional fusion protein containing the maltose-binding polypeptide and the catalytic chain of aspartate transcarbamoylase: assembly, oligomers, and domains. Biophys. Chem. 59, 289-297 (1996)

Optima XL-A, sed. equil., m, sed. vel., g*(s), S; recombinant maltose-binding protein complex and cleavage products; 50 krpm (s.v.), 235 or 280 nm, 20deg.C; PAGE also used; (Schachman) Dept. of Molecular and Cell Biology, Wendell M. Stanley Hall, Univ. of California, Berkeley, CA 94720-3206

**Yoo, S. H., Lewis, M. S. Thermodynamic study of the pH-dependent interaction of chromogranin A with an intraluminal loop peptide of the inositol 1,4,5-trisphosphate receptor. Biochemistry 34, 632-638 (1995)

Optima XL-A, sed. equil., delta C, delta G, delta H, delta S; chromagranin A-intraluminal loop peptide interaction; 10 krpm; 6, 10, 14, 18 & 22deg.C; 280, 290, 295, 300, 305 & 310 nm; multiwavelength scans; effect of pH, temperature & calcium ion; Laboratory of Cellular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892

**Yoo, S. H., Lewis, M. S. Effects of pH and Ca(2+) on heterodimer and heterotetramer formation by chromogranin A and chromogranin B. J. Biol. Chem. 271, 17041-17046 (1996)

Optima XL-A, sed. equil., delta C, delta G, delta H, T delta S; beef adrenal chromogranin A and chromogranin B heterodimer and heterotetramer formation; 8 krpm, 2, 5, 8, 11, 14, 17, and 20deg.C; 280 nm, effect of pH and temperature; Laboratory of Neurochemistry, 5 Research Court, 2A37 NIDCD, Natl. Inst. of Health, Bethesda, MD 20892-3320

General Studies

**Adams, E. T., Jr. Sedimentation coefficients of self-associating species. Analysis of monomer-dimer-n-mer associations and some indefinite associations. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 407-427. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Sedimentation velocity analysis theory for self-associating systems; Chemistry Dept., Texas A & M Univ., College Station, TX 77843

**Ansevin, A. T., Roark, D. E., Yphantis, D. A. Improved ultracentrifuge cells for high-speed sedimentation equilibrium studies with interference optics. Anal. Biochem. 34, 237-261 (1970)

**Arakawa, T., Timasheff, S. N. Calculation of the partial specific volume of proteins in concentrated salt and amino acid solutions. Methods in Enzymology, Vol. 117, pp. 60-65. Edited by C. H. W. Hirs and S. N. Timasheff. New York, Academic Press, 1985.

**Attri, A. K., Lewis, M. S. A fitting function for the analysis of sedimentation velocity concentration distributions. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 138-146. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Model E with absorption optics, sed. vel. concentration distributions for ovalbumin, rabbit muscle aldolase-bovine serum albumin mixture; Lab. of Cell Biology, National Heart, Lung and Blood Institute and Biomedical Engineering and Instrumentation Program, National Center for Research Resources, National Institutes of Health, Bethesda, MD 20892

**Baldwin, R. L. Boundary spreading in sedimentation velocity experiments. III. Effects of diffusion on the measurement of heterogeneity when concentration dependence is absent. J. Phys. Chem. 58, 1081-1086 (1954)

**Becerra, S. P., Kumar, A., Lewis, M. S., Widen, S. G., Abbotts, J., Karawya, E. M., Hughes, S. H., Shiloach, J., Wilson, S. H. Protein-protein interactions of HIV-1 reverse transcriptase: implication of central and C-terminal regions in subunit binding. Appendix: Ultracentrifugal analysis of mixed association, by M. S. Lewis. Biochemistry 30, 11707-11719 (1991)

Data analysis for heteroassociation

**Beckett, D., Nenortas, E. Measurement of protein-protein association equilibria by large zone analytical gel filtration chromatography and equilibrium analytical ultracentrifugation. Adv. Biophys. Chem. 5, 233-262 (1995)

The Optima XL-A and Model E are both mentioned in this overview

**Borchard, W. Swelling pressure equilibrium of swollen crosslinked systems in an external field. I. Theory. Progress in Colloid & Polymer Science, Vol. 86, pp. 84-91. Edited by H.-G. Kilian, G. Lagaly and W. Borchard. Darmstadt, Steinkopff Verlag, 1991.

Theory of gel behavior of crosslinked substances in an ultracentrifugal field; Angewandte Physikalische Chemie der Universitat GH Duisburg, FRG

**Borchard, W. The sedimentation diffusion equilibrium of a ternary gel. Progress in Colloid & Polymer Science, Vol. 94, pp. 82-89. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Sedimentation equilibrium theory for ternary gels; Angewandte Physikalische Chemie der Universitat GH Duisburg, FRG

**Braswell, E. H. Polyelectrolyte charge corrected molecular weight and effective charge by sedimentation. Biophys. J. 51, 273-281 (1987)

Unspecified analytical ultracentrifuge, interference optics, sed. equil., sed. vel., calculation of effective charge and true molecular weight of polyelectrolytes

**Budd, P. M. Sedimentation analysis of synthetic polyelectrolytes. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 593-608. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Sedimentation velocity and sedimentation equilibrium theory; concentration dependence of s; frictional coefficient; Dept. of Chemistry, Univ. of Manchester, Oxford Road, Manchester, M13 9PL U.K.

**Budd, P. M. Sedimentation and diffusion of polyelectrolytes. Progress in Colloid & Polymer Science, Vol. 94, pp. 107-115. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Sedimentation velocity and diffusion behavior of polyelectrolytes; Dept. of Chemistry, Univ. of Manchester, Manchester, UK

**Cann, J. R. Theory of sedimentation for ligand-mediated heterogeneous association-dissociation reactions. Biophys. Chem. 16, 41-49 (1982)

**Cann, J. R. Computer simulation of the sedimentation of ligand-mediated and kinetically controlled macromolecular interactions. Modern Analytical Ultracentrifugation, pp. 171-188. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Dept. of Biochemistry/Biophysics/Genetics, Univ. of Colorado, Denver, CO 80262

**Cann, J. R., Coombs, R. O., Howlett, G. J., Jacobsen, M. P., Winzor, D. J. Effects of molecular crowding on protein self-association: a potential source of error in sedimentation coefficients obtained by zonal ultracentrifugation in a sucrose gradient. Biochemistry 33, 10185-10190 (1994)

Optima XL-A, sed. vel., S; results compared with simulated run in SW 60 Ti with a sucrose gradient; yeast enolase used as a model dimerizing system; 60 krpm; effect of sucrose on polymerization equilibrium; (Winzor) Dept. of Biochemistry, Univ. of Queensland, Brisbane, QLD4072, Australia

**Chatelier, R. C., Minton, A. P. Sedimentation equilibrium in macromolecular solutions of arbitrary concentration. I. Self-associating proteins. Biopolymers 26, 507-524 (1987)

Simulation of sedimentation equilibrium of self-associating systems; estimation of true weight-average molecular weight; Dept. of Biochemistry/Biophysics/Genetics, Univ. of Colorado, Denver, CO 80262

**Chatelier, R. C., Minton, A. P. Sedimentation equilibrium in macromolecular solutions of arbitrary concentration. II. Two protein components. Biopolymers 26, 1097-1113 (1987)

Simulation of sedimentation equilibrium of heteroassociations; estimation of true weight-average molecular weight

**C^lfen, H. Analytical ultracentrifugation of gels. Colloid Polym. Sci. 273, 1101-1137 (1995)

A review of analytical ultracentrifugation studies of both biological and synthetic gels; Max-Planck-Institute for Colloid and Interface Research, Colloid Chemistry Dept., Kanstrasse 55, 14513 Taltow-Seehof, Germany

**C^lfen, H., Holtus, G., Borchard, W. Multifunctional cell for measurements of temperature, distance, and refractive index as for determining optical calibration factors in rotating systems. Rev. Sci. Instr. 64, 2999-3005 (1993)

Special temperature-measuring cell that can be used in Model E or XL-A; Angewandte Physikalische Chemie der Univ.-GH-Duisburg, Lotharstr. 1, D47048 Duisburg, Germany

**C^lfen, H., Harding, S. E.. A study on Schlieren patterns derived with the Beckman Optima XL-A UV-absorption optics. Progress in Colloid & Polymer Science, Vol. 99, pp. 167-186. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A, sed. vel., schlieren effect derived with absorption optics used to examine various polysaccharides: chitosan, kappa-carrageenan, Na-alginate, dextrans 20 and 150, and xanthan; 12.6-60 krpm, 20deg.C, 276-600 nm; results compared to Model E with schlieren optics; Max-Planck-Inst. for Colloid and Interface Research, Colloid Chemistry Dept., Kantstrasse 55, 14513 Teltow, Germany

**Condino, J. The determination of molecular weights by sedimentation equilibrium. Technical Information DS-820. Palo Alto, Calif., Spinco Business Unit, 1992.

Brief overview of sedimentation equilibrium

**Condino, J. Sample preparation for analytical ultracentrifugation in the Optimaô XL-A. Technical Information LXL/A-AN-001. Palo Alto, Calif., Spinco Business Unit, 1992.

**Correia, J. J., Yphantis, D. A. Equilibrium sedimentation in short solution columns. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 231-252. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Model E, interference optics, short-column sedimentation equilibrium methodology; Dept. of Molecular and Cell Biology, Univ. of Connecticut, Box U-125, Storrs, CT 06269-3125

**Cox, D. J., Dale, R. S. Simulation of transport experiments for interacting systems. Protein-Protein Interactions, pp. 173-211. Edited by C. Frieden and L. W. Nichol. New York, John Wiley & Sons, 1981.

**Creeth, J. M., Knight, C. G. On the estimation of the shape of macromolecules from sedimentation and viscosity measurements. Biochim. Biophys. Acta 102, 549-558 (1965)

**Darawshe, S., Minton, A. P. Quantitative characterization of macromolecular associations in solution via real-time and postcentrifugation measurements of sedimentation equilibrium: a comparison. Anal. Biochem. 220, 1-4 (1994)

Optima XL-A and Brandel FR-115 Microfractionator techniques are compared and deemed complementary; Laboratory of Biochemical Pharmacology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892

**de la Torre, J. G. Sedimentation coefficients of complex biological particles. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 333-345. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Sedimentation velocity theory for rigid, spherical particles, ellipsoids, cylinders, bead models; table of sedimentation, diffusion & frictional ratios for monomers to octamers of different shapes; Dept. de Quimica Fisica, Facultad de Ciencias Quimicas y Matematicas Univ. de Murcia, 30071 Murcia, Spain

**Dhami, R., C^lfen, H., Harding, S. E. A comparative "Schlieren" study of the sedimentation behaviour of three polysaccharides using the Beckman Optima XL-A and Model E analytical ultracentrifuges. Progress in Colloid & Polymer Science, Vol. 99, pp. 187-192. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A schlieren effect results compared with Model E schlieren results, sed. vel., K(s), S; polysaccharides: arabinoxylan, xanthan and locust bean gum; 30 or 60 krpm, 200-600 nm, 20deg.C; (Harding) Natl. Ctr. for Macromolecular Hydrodynamics, Univ. of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK

**Durchschlag, H., Zipper, P. Calculation of the partial volume of organic compounds and polymers. Progress in Colloid & Polymer Science, Vol. 94, pp. 20-39. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Tables of partial molar volume increments for selected atoms and atomic groups; table of calculated and experimental partial specific volumes of organic compounds and biochemicals; (Durchschlag) Institute of Biophysics and Physical Biochemistry, Univ. of Regensburg, FRG

**Ebel, C. Characterisation of the solution structure of halophilic proteins. Analytical centrifugation among complementary techniques (light, neutron and X-ray scattering, density measurements). Progress in Colloid & Polymer Science, Vol. 99, pp. 17-23. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Overview of complementary techniques used for studies of halophilic proteins; Institut de Biologie Structurale, 41 Avenue des Martyrs, 38 027 Grenoble Cedex 1, France

**Edelstein, S. J., Schachman, H. K. The simultaneous determination of partial specific volumes and molecular weights with microgram quantities. J. Biol. Chem. 242, 306-311 (1967)

**Edsall, J. T. Apparent molal volume, heat capacity, compressibility and surface tension of dipolar ions in solutions. Proteins, Amino Acids and Peptides as Ions and Dipolar Ions, pp. 155-176. Edited by E. J. Cohn, and J. T. Edsall. New York, Rheinhold, 1943.

**Eisenberg, H. Protein and nucleic acid hydration and cosolvent interactions: establishment of reliable baseline values at high cosolvent concentrations. Biophys. Chem. 53, 57-68 (1994)

Optima XL-A mentioned in this overview of methods including light, neutron, and X-ray scattering; Dept. of Structural Biology, Weizmann Inst. of Science, Rehovot 76100, Israel

**Eisenberg, H. Birth of the macromolecule. Biophys. Chem. 59, 247-257 (1996)

Historical overview of early macromolecular chemistry and the Svedberg's analytical ultracentrifuge; Dept. of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel

**Freire, J. J., de la Torre, J. G. Sedimentation coefficients of flexible chain polymers. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 346-358. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Sedimentation velocity theory; excluded volume & theta conditions; linear and nonlinear chains, branched chains, rings; (de la Torre) Dept. de Quimica Fisica, Facultad de Ciencias Quimicas y Matematicas Univ. de Murcia, 30071 Murcia, Spain

**Fujita, H. Notes on the derivation of sedimentation equilibrium equations. Modern Analytical Ultracentrifugation, pp. 3-14. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Sedimentation equilibrium theory; 35 Shimotakedono-Cho, Shichiku, Kita-Ku, Kyoto, Japan

**Furst, A. Overview of sedimentation velocity for the Optima XL-A Analytical Ultracentrifuge. Technical Information DS-819. Palo Alto, Calif., Spinco Business Unit, 1991.

Brief description of Optima XL-A; sedimentation velocity overview

**Genetic Engineering News. AU gains followers. Genet. Eng. News 13:4, 9, 29 (Feb. 15, 1993)

Comments of Optima XL-A users John Philo (Amgen), Preston Hensley (SmithKline Beecham), and Leo Einck (Hem Pharmaceuticals); Complementary techniques such as light scattering and mass spectroscopy also mentioned

**Giebeler, R. The Optima XL-A: a new analytical ultracentrifuge with a novel precision absorption optical system. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 16-25. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Description of the Optima XL-A hardware and data acquisition software

**Gmachowski, L. A universal curve representing the concentration and molecular weight dependences of sedimentation coefficient. Polym. J. 22, 771-775 (1990)

**Goldberg, R. J. Sedimentation in the ultracentrifuge. J. Phys. Chem. 57, 194-202 (1953)

**Gosting, L. J. Solution of boundary spreading equations for electrophoresis and the velocity ultracentrifuge. J. Am. Chem. Soc. 74, 1548-1552 (1952)

**Hansen, J. C., Lebowitz, J., Demeler, B. Analytical ultracentrifugation of complex macromolecular systems. Biochemistry 33, 13155-13163 (1994)

Overview of recent analytical ultracentrifuge studies, data acquisition and analysis, and future prospects of the Optima XL-A; Dept. Biochem., Univ. of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78284-7760

**Harding, S. E. Automatic data capture and analysis of Rayleigh interference fringe displacements in analytical ultracentrifugation. Opt. Lasers Eng. 8, 83-96 (1988)

**Harding, S. E. Analytical ultracentrifugation and the genetic engineering of macromolecules. Biotechnol. Genet. Eng. Rev. 11, 317-356 (1993)

Overview of analytical ultracentrifuge methods and applications; table of techniques for macromolecular physical characterization; review of genetically engineered products that have been characterized; National Centre for Macromolecular Hydrodynamics, School of Agriculture, Univ. of Nottingham, Sutton Bonington, UK

**Harding, S. E. Determination of macromolecular homogeneity, shape, and interactions using sedimentation velocity analytical ultracentrifugation. Microscopy, Optical Spectroscopy, and Macroscopic Techniques, pp. 61-73. Edited by C. Jones, B. Mulley, A. H. Thomas. Totowa, NJ, Humana Press, 1994.

The Optima XL-A is mentioned, along with other commercial ultracentrifuge models, in this brief overview of sedimentation velocity; Dept. of Applied Biochemistry and Food Science, Univ. of Nottingham, UK

**Harding, S. E. Determination of absolute molecular weights using sedimentation equilibrium analytical ultracentrifugation. Microscopy, Optical Spectroscopy, and Macroscopic Techniques, pp. 75-84. Edited by C. Jones, B. Mulley, A. H. Thomas. Totowa, NJ, Humana Press, 1994.

A brief overview of sedimentation equilibrium; Dept. of Applied Biochemistry and Food Science, Univ. of Nottingham, UK

**Harding, S. E. Sedimentation equilibrium analysis of glycopolymers. Progress in Colloid & Polymer Science, Vol. 94, pp. 54-65. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Overview of sedimentation equilibrium methods for determining molar mass of glycoconjugates and polysaccharides using schlieren or interference optics; Univ. of Nottingham, School of Agriculture, Sutton Bonington, UK

**Harding, S. E. The analytical ultracentrifuge spins again. Trends Anal. Chem. 13, 439-446 (1994)

Optima XL-A and Model E mentioned; overview of methodologies and their applications; National Centre for Macromolecular Hydrodynamics, Univ. of Nottingham School of Agriculture, Sutton Bonington, LE12 5RD, UK

**Harding, S. E. The sedimentation equilibrium analysis of polysaccharides and mucins: a guided tour of problem solving for difficult heterogeneous systems. Modern Analytical Ultracentrifugation, pp. 313-341. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Sedimentation equilibrium methods, nonideality factors, and data analysis for mucopolysaccharides; Univ. of Nottingham, School of Agriculture, Sutton Bonington LE12 5RD, UK

**Harding, S. E. On the hydrodynamic analysis of macromolecular conformation. Biophys. Chem. 55, 69-93 (1995)

Univ. of Nottingham, School of Agriculture, Sutton Bonington LE12 5RD, UK

**Harding, S. E. Some recent developments in the size and shape analysis of industrial polysaccharides in solution using sedimentation analysis in the analytical ultracentrifuge. Carbohydr. Polym. 28, 227-237 (1995)

Overview of sedimentation equilibrium and velocity methods, and review of applications; Optima XL-I mentioned; Univ. of Nottingham, Dept. of Applied Biochemistry and Food Science, Sutton Bonington LE12 5RD, UK

**Harding, S. E. Ultracentrifugation of food biopolymers. New Physico-Chemical Techniques for the Characterization of Complex Food Systems, pp. 109-138. Edited by E. Dickinson. London, Blackie Academic & Professional, 1995.

Optima XL-A, Model E and MOM analytical ultracentrifuges mentioned in this overview of techniques and applications to food biopolymers; tables listing sedimentation velocity parameters and shape characteristics of various food proteins, glycoproteins and polysaccharides; Dept. of Applied Biochemistry and Food Science, Univ. of Nottingham, UK

**Harding. S. E., C^lfen, H. Inversion formulae for ellipsoid of revolution macromolecular shape functions. Anal. Biochem. 228, 131-142 (1995)

(C^lfen) Colloid Chemistry Dept., Max-Planck Inst. for Colloid Research, D-14513 Teltow, Germany

**Harding, S. E., Rowe, A. J., Horton, J. C., eds. Analytical Ultracentrifugation in Biochemistry and Polymer Science. Cambridge, Royal Society of Chemistry, 1992.

Comprised of 33 papers mentioning use of both the Optima XL-A and Model E

**Harding, S. E., Horton, J. C., Morgan, P. J. MSTAR: a FORTRAN program for the model independent molecular weight analysis of macromolecules using low speed or high speed sedimentation equilibrium. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 275-294. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society

of Chemistry, 1992.

Optima XL-A, sed. equil., human IgM(1), MSTARA for data analysis; Univ. of Nottingham, Dept. of Applied Biochemistry and Food Science, Sutton Bonington, LE12 5rd U.K.

**Harrington, W. F. The effects of pressure in ultracentrifugation of interacting systems. Fractions 1975, No. 1, 10-18. (Fractions was formerly published by Beckman Instruments, Inc., Spinco Division, Palo Alto.)

**Harrington, W. F., Kegeles, G. Pressure effects in ultracentrifugation of interacting systems. Methods in Enzymology, Vol. 27, pp. 306-345. Edited by C. H. W. Hirs and S. N. Timasheff. New York, Academic Press, 1973.

**Hayes, D. B., Laue, T. M. A graphical method for determining the ideality of a sedimenting boundary. Modern Analytical Ultracentrifugation, pp. 245-258. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Model E, interference optics, sed. vel., graphical method for testing quality of sedimenting boundary using bovine serum albumin monomer as an example; Dept. of Biochemistry, Univ. of New Hampshire, Durham, NH 03824

**Hedges, J., Sarrafzadeh, S., Lear, J. D., McRorie, D. K. Extensions to commercial graphics packages for customization of analysis of analytical ultracentrifuge data. Modern Analytical Ultracentrifugation, pp. 227-244. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A data analysis using extended Originô (MicroCal Software, Inc.) software; examples of sedimentation equilibrium data analysis of coiled-coil Trp peptide given; Beckman Instruments, Inc., 1050 Page Mill Road, Palo Alto, CA 94304

**Hensley, P. Defining the structure and stability of macromolecular assemblies in solution: the re-emergence of analytical ultracentrifugation as a practical tool. Structure (London) 4, 367-373 (1996)

Overview of analytical ultracentrifuge methods and other techniques for characterizing molecular interactions; Optima XL-I mentioned; Figure 1 compares methods for interaction studies: mass spectrometry, surface plasmon resonance, AUC, calorimetry, and spectroscopy methods; Dept. of Macromolecular Sciences, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406-0939

**Holzman, T. F., Snyder, S. W. Applications of analytical ultracentrifugation in structure-based drug design. Modern Analytical Ultracentrifugation, pp. 298-314. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Discussion of data acquisition and analysis methods for the Model E with Scanner, Prep UV Scanner and Optima XL-A; example analyses shown for ligand-induced association of CMP-KDO synthetase in D(2)O and human beta-amyloid A4 peptide; Abbott Laboratories, Protein Biochemistry, D-46Y Discovery Research, Pharmaceutical Products, Abbott Park, IL 60048.

**Horbett, T. A., Teller, D. C. An experimental study of baseline reproducibility and its effect on high-speed sedimentation equilibrium data. Anal. Biochem. 45, 86-99 (1972)

**Howlett, G. J. Sedimentation analysis of membrane proteins. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 470-483. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Discussion of both analytical and preparative ultracentrifuge methods, using sedimentation velocity, sedimentation equilibrium and density gradient techniques; determination of M, v-bar; Russell Grimwade School of Biochemistry, Univ. of Melbourne, Parkville 3052, Victoria, Australia

**Howlett, G. J., Jeffrey, P. D., Nichol, L. W. The effects of pressure on the sedimentation equilibrium of chemically reacting systems. J. Phys. Chem. 74, 3607-3610 (1970)

**Hsu, C. S., Minton, A. P. A strategy for efficient characterization of macromolecular heteroassociations via measurement of sedimentation equilibrium. J. Mol. Recognit. 4, 93-104 (1991)

Method for selecting experimental conditions for sedimentation equilibrium analysis of heteroassociating systems

**Huber, E., Schuck, P., Schubert, D. Analytische Ultrazentrifugation in der modernen Biochemie. LaborPraxis 2000, 55-56, 59-60 (1992)

Optima XL-A described; Institut fur Biophysik der Johann Wolfgang Goethe-Universitat, Theodor-Stern-Kai 7, Haus 74, 6000 Frankfurt/Main 70.

**Jacobsen, M. P., Winzor, D. J. Refinement of the omega analysis for the characterization of solute self-association by sedimentation equilibrium. Biophys. Chem. 45, 119-132 (1992)

Sedimentation equilibrium data analysis

**Jeffrey, P. Measuring protein molecular weights by equilibrium sedimentationóis the partial specific volume a problem? Today's Life Sci. 3:12, 50 (Dec. 1991)

Discussion of v-bar as a source of error in analytical ultracentrifugation; recommends use of 0.72 mL/g if amino acid composition is unknown

**Johnson, J. B., Becker, K., Edwards, G. Pressure corrections for CoCl(2) as a thermometer in an analytic ultracentrifuge. Anal. Biochem. 227, 385-387 (1995)

Pressure corrections given for 0-40deg.C; Dept. of Chemistry, Biochemistry, and Physics, Arkansas State Univ., State Univ., AR 72467

**Johnston, J. P., Ogston, A. G. A boundary anomaly found in the ultracentrifugal sedimentation of mixtures. Trans. Faraday Soc. 42, 789-799 (1946)

**Johnson, M. L., Straume, M. Comments on the analysis of sedimentation equilibrium experiments. Modern Analytical Ultracentrifugation, pp. 37-65. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Sedimentation equilibrium theory; Dept. of Pharmacology and Internal Medicine, Box 448, Univ. of Virginia Health Sciences Center, Charlottesville, VA 22908

**Joss, L. A., Ralston, G. B. beta-Lactoglobulin B: a proposed standard for the study of reversible self-association reactions in the analytical ultracentrifuge? Anal. Biochem. 236, 20-26 (1996)

Optima XL-A, sed. equil., delta G, delta H, delta S, state of association; beef milk beta-lactoglobulin B monomer-dimer; 25-30 krpm, 280 nm, 5-30deg.C; Dept. of Biochemistry, Univ. of Sydney, Sydney, New South Wales 2006, Australia

**Kegeles, G. Convection induced by hydrostatic pressure in sedimentation velocity experiments. Biopolymers 7, 83-86 (1969)

**Kegeles, G., Rhodes, L., Bethune, J. L. Sedimentation behavior of chemically reacting systems. Proc. Natl. Acad. Sci. 58, 45-51 (1967)

**Kegeles, G., Kaplan, S., Rhodes, L. The effects of pressure in high-speed ultracentrifugation of chemically reacting systems. Ann. N. Y. Acad. Sci. 164, 183-191 (1969)

**Kuntz, I. D. Hydration of macromolecules. III. Hydration of polypeptides. J. Am. Chem. Soc. 93, 514-516 (1971)

**Laue, T. M. On-line data acquisition and analysis from the Rayleigh interferometer. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 63-89. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Justification for interferometry vs. absorbance; solid state camera detectors; alignment; fringe displacement measurement; Dept. of Biochemistry, Univ. of New Hampshire, Durham, NH 03824

**Laue, T. M. Short column sedimentation equilibrium analysis for rapid characterization of macromolecules in solution. Technical Information DS-835. Palo Alto, Calif., Spinco Business Unit, 1992.

Short-column sedimentation equilibrium methods and applications

**Laue, T. M. Sedimentation equilibrium as thermodynamic tool. Methods in Enzymology, Vol. 259, pp. 427-452. Edited by M. L. Johnson and G. K. Ackers. San Diego, Academic Press, 1995.

Optima XL-A, sedimentation equilibrium protocol and extraction of thermodynamic quantities from data; Dept. of Biochemistry and Molecular Biology, Univ. of New Hampshire, Durham, NH 03824

**Laue, T. M. Analytical ultracentrifugation. Current Protocols in Protein Science, pp. 7.5.1-7.5.9. Edited by J. E. Coligan and others. N.Y., J. Wiley, 1996.

Introductory overview of analytical ultracentrifugation, including summaries of methods and alternative techniques, methods of solute detection, experimental design and troubleshooting guide; Univ. of New Hampshire, Durham, NH

**Laue, T. M., Rhodes, D. G. Determination of size, molecular weight, and presence of subunits. Methods in Enzymology, Vol. 182, pp. 566-587. Edited by M. P. Deutscher. San Diego, Academic Press, 1990.

Overview of various methods, including analytical ultracentrifugation

**Laue, T. M., Shah, B. D., Ridgeway, T. M., Pelletier, S. L. Computer-aided interpretation of analytical sedimentation data for proteins. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 90-125. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Discussion of data required for analysis; tables of v-bar for amino acids, carbohydrates, denaturants, detergents, ions, organic acids, glycerol, ethanol, etc.; solvent density; effect of buffer composition on rho; coefficients for power series for density and viscosity; estimating protein hydration and assymetry; axial ratio; Dept. of Biochemistry, Spaulding Life Sciences Building, Univ. of New Hampshire, Durham, NH 03824

**Laue, T. M., Anderson, A. L., Demaine, P. D. An on-line interferometer for the XL-A ultracentrifuge. Progress in Colloid & Polymer Science, Vol. 94, pp. 74-81. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Overview of design and use of a Rayleigh interference optical system for the Optima XL-A; Univ. of New Hampshire, Dept. of Biochemistry and Molecular Biology, Durham, NH

**Lavrenko, P. N. Analysis of polymer heterogeneity by sedimentation transport: 1. Method of moments, a new approach. Polymer 35, 2133-2136 (1994)

Method of moments procedure for determining polydispersity indices, such as M(z)/M(w), from sedimentation velocity data; Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg 199004, Russia

**Lechner, M. D., Machtle, W. A new procedure for the determination of the molar mass distribution of polymers in solution from sedimentation equilibrium. Progress in Colloid & Polymer Science, Vol. 86, pp. 62-69. Edited by H.-G. Kilian, G. Lagaly and W. Borchard. Darmstadt, Steinkopff Verlag, 1991.

Unspecified analytical ultracentrifuge, interference or schlieren optics, molar mass distribution; polystyrenes, sodium polystyrene sulfonate

**Lechner, M. D., Machtle, W. A new procedure for the determination of molar mass distribution from sedimentation equilibrium runs in an analytical ultracentrifuge (AUC), 1. Measurements with interference optics. Makromol. Chem. 192, 1183-1192 (1991)

Model E, interference optics, sed. equil., M; polystyrene (Simplex procedure used to calculate number-, weight-, and z-average molecular weight); 4 & 5.6 krpm; 25 & 35deg.C

**Lee, J. C., Rajendran, S. Studies of macromolecular interaction by sedimentation velocity. Modern Analytical Ultracentrifugation, pp. 138-155. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Simulated sedimentation velocity profiles; Dept. of Human Biochemistry/Genetics, Univ. of Texas Medical Branch, 617C Basic Science Building, F-47, Galveston, TX 77555-0647

**Lewis, M. S. Data acquisition and analysis systems for the absorption optical system of the analytical ultracentrifuge. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 126-137. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Model E, overview of data acquisition and analysis systems; Biomedical Engineering and Instrumentation Program, National Center for Research Resources, National Institutes of Health, Bethesda, MD 20892

**Liu, S., Stafford, W. F., III. An optical thermometer for direct measurement of cell temperature in the Beckman Instruments XL-A analytical ultracentrifuge. Anal. Biochem. 224, 199-202 (1995)

Optima XL-A, CoCl(2) temperature-sensitive solution used to monitor cell temperature; 3000 rpm, 450-750 nm; Boston Biomedical Research Institute, 20 Staniford St., Boston MA 02114

**Lollar, P. Heterogeneous, ideal associations at sedimentation equilibrium. Biophys. Chem. 28, 245- 251 (1987)

Analysis of mA + nB = A(m)B(n) heteroassociation; effects of random error and presence of contaminants

**Machtle, W. Future requirements for modern analytical ultracentrifuges. Progress in Colloid & Polymer Science, Vol. 86, pp. 111-118. Edited by H.-G. Kilian, G. Lagaly and W. Borchard. Darmstadt, Steinkopff Verlag, 1991.

Shortcomings of both the Model E and the Optima XL-A discussed

**Machtle, W. Determination of highly resolved particle size distributions in the submicron range by ultracentrifugation. Makromol. Chem., Macromol. Symp. 61, 131-142 (1992)

Optima XL modified with 690-nm red light laser optics; Model L(?) modified with turbidity optics and analytic 8-cell rotor; schematics and photos shown; particle size distributions of Dow polystyrene latex, polybutadiene mixture, and carotenoid pigments (food dyes); some analyses done in H(2)O-D(2)O; Kunststofflaboratorium, BASF Aktiengelsellschaft, D-6700 Ludwigshafen, Germany

**McMeekin, T. L., Marshall, K. Specific volumes of proteins and the relationship to their amino acid contents. Science 116, 142-143 (1952)

**McRorie, D. K., Voelker, P. J. Self-Associating Systems in the Analytical Ultracentrifuge. Fullerton, CA, Beckman Instruments, Inc., 1993.

A primer covering molecular weight determinations by sedimentation equilibrium, nonlinear least-squares analysis, goodness of fit and a rational approach to modeling self-associating systems (Appendix A), tables of partial specific volume, and solvent density

**Minton, A. P. Conservation of signal: a new algorithm for the elimination of the reference concentration as an independently variable parameter in the analysis of sedimentation equilibrium. Modern Analytical Ultracentrifugation, pp. 81-93. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Sedimentation equilibrium data analysis algorithm; Lab. of Biochemical Pharmacology, Natl. Inst. of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892

**Modern Analytical Ultracentrifugation; Acquisition and Interpretation of Data for Biological and Synthetic Polymer Systems. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Comprised of 17 papers mentioning use of both the Optima XL-A and the Model E

**Morris, M. B., Ralston, G. B. Biophysical characterization of membrane and cytoskeletal proteins by sedimentation analysis. Subcellular Biochemistry, Vol. 23, pp. 25-82. Edited by H. J. Hilderson and G. B. Ralston. New York, Plenum Press, 1994.

Optima XL-A and Model E described; overview of sedimentation analysis methods; Dept. of Biochemistry, The Univ. of Sydney, Sydney, NSW 2006

**Ogston, A. G. On the variation of the sedimentation rate of spherical particles with concentration. J. Phys. Chem. 65, 51-53 (1961)

**Pavlov, G., Frenkel, S. Sedimentation parameter of linear polymers. Progress in Colloid & Polymer Science, Vol. 99, pp. 101-108. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

The relationship between the sedimentation coefficient and its concentration coefficient obtained by sedimentation velocity is discussed.; Institute of Physics Univ., Ulyanovskaya 1 Petergof, St. Petersburg 198904, Russia

**Perkins, S. J. Protein volumes and hydration effects. The calculation of partial specific volumes, neutron scattering matchpoints and 280-nm absorption coefficients for proteins and glycoproteins from amino acid sequences. Eur. J. Biochem. 157, 169-180 (1986)

**Petrus, V., Bohdanecky, M., Bareiss, R. E. The effect of polymolecularity on the determination of the weight average sedimentation coefficient. Poly. Commun. 31, 68-70 (1990)

Sedimentation velocity theory

**Philo, J. S. Measuring sedimentation, diffusion, and molecular weights by direct fitting of sedimentation velocity concentration profiles. Modern Analytical Ultracentrifugation, pp. 156-170. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A, sed. vel., D, m, S; recombinant brain-derived neurotrophic growth factor, transforming growth factor alpha and bovine serum albumin; Protein Chemistry Dept. 14-2-A-223, Amgen, Inc., Amgen, Inc., Amgen Center, Thousand Oaks, CA 91320

**Prakash, V., Timasheff, S. N. Calculation of partial specific volumes of proteins in 8 M urea solutions. Methods in Enzymology, Vol. 117, pp. 53-60. Edited by C. H. W. Hirs and S. N. Timasheff. New York, Academic Press, 1985.

**Ralston, G. B., Teller, D. C., Bukowski, T. The use of metrizamide for stabilizing against convection in sedimentation equilibrium. Anal. Biochem. 178, 198-201 (1989)

Model E, interference optics, metrizamide used to prevent thermal convection during sedimentation equilbrium of spectrin

**Ralston, G. The renaissance of the analytical ultracentrifuge. Today's Life Sci. 3:12, 42-50 (Dec. 1991)

Overview of analytical ultracentrifugation; photos of Model E and Optima XL-A; brief discussions of applications: molecular weight determination, associating systems, sample purity, conformation changes, density gradient, study of crowding effects; description of XL-A; author is at the Dept. of Biochemistry, Univ. of Sydney

**Ralston, G. Introduction to Analytical Ultracentrifugation. Fullerton, CA, Beckman Instruments, Inc., 1993.

A primer of theory, methods, and applications of the Optima XL-A

**Ralston, G. Analytical ultracentrifugation. Lab. News, 18-19, 22 (March 1994)

Introductory-level article;Optima XL-A is briefly described; Univ. of Sydney, Australia

**Ralston, G. B., Morris, M. B. The use of the omega function for sedimentation equilibrium analysis. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 253-274. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Discussion of omega function for analysis of sed. equil. data for self-associating molecules; tests for heterogeneity; extrapolation to infinite dilution; nonideality; activity coefficients; Dept. of Biochemistry, The Univ. of Sydney, Sydney, NSW 2006, Australia

**Reynolds, J. A., Tanford, C. Determination of molecular weight of the protein moiety in protein-detergent complexes without direct knowledge of detergent binding. Proc. Natl. Acad. Sci. 73, 4467-4470 (1976)

**Rhodes, D. G., Laue, T. M. Determination of purity. Methods in Enzymology, Vol. 182, pp. 555-565. Edited by M. P. Deutscher. San Diego, Academic Press, 1990.

Overview of several methods, including analytical ultracentrifugation

**Richards, E. G., Schachman, H. K. A differential ultracentrifuge technique for measuring small changes in sedimentation coefficients. J. Am. Chem. Soc. 79, 5324-5325 (1957)

**Rivas, G., Minton, A. P. New developments in the study of biomolecular associations via sedimentation equilibrium. Trends Biochem. Sci. 18, 284-287 (1993)

Optima XL-A, Model E, Brandel FR-115 Microfractionator mentioned and briefly described as sedimentation equilibrium methods for studies of macromolecular associations; (Rivas) Dept. of Biophysical Chemistry, Biocenter of the Univ. of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland

**Roark, D. E. Sedimentation equilibrium techniques: multiple speed analyses and an overspeed procedure. Biophys. Chem. 5, 185-196 (1976)

**Roark, D. E., Yphantis, D. A. Studies of self-associating systems by equilibrium ultracentrifugation. Ann. N. Y. Acad. Sci. 164, 245-278 (1969)

**Rowe, A. J. The concentration dependence of sedimentation. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 394-406. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Determination of K(s); sedimentation velocity theory; estimation of M(r) from s and k(s); National Centre for Macromolecular Hydrodynamics, Univ. of Leicester, Leicester LE1 7RH, U.K.

**Rowe, A. J., Jones, S. W., Thomas, D. G., Harding, S. E. Methods for off-line analysis of sedimentation velocity and sedimentation equilibrium patterns. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 49-62. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Model E, MSE Mk II or MSE Centriscan mentioned; data analysis for interference and schlieren optics; National Centre for Macromolecular Hydrodynamics, Univ. of Leicester, Leicester LE1 7RH, U.K.

**Roxby, R. W. Sedimentation analysis of micelle-forming systems. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 609-618. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Sedimentation equilibrium and sedimentation velocity of micellar systems; Dept. of Biochemistry, Microbiology and Molecular Biology, Univ. of Maine, Orono, Maine 04469

**Schachman, H. K. Is there a future for the ultracentrifuge? Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 3-15. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

History of analytical ultracentrifugation; Dept. of Molecular and Cell Biology, W. M. Stanley Hall, Univ. of California, Berkeley, CA 94720

**Scholte, T. G. Molecular weights and molecular weight distribution of polymers by equilibrium ultracentrifugation. Part I. Average molecular weights. J. Polym. Sci., Pt. A-2, 6, 91-109 (1968)

**Schuck, P. Simultaneous radial and wavelength analysis with the Optima XL-A analytical ultracentrifuge. Progress in Colloid & Polymer Science, Vol. 94, pp. 1-13. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil., extinction profiles, M(r); human erythrocyte band 3 protein, DBDS nonionic detergent and oxyhemoglobin mixtures studied as model systems; 11-12,500 rpm; mathematical analysis described; 4deg.C, 270-340 nm; Institut fur Biophysik der Johann Wolfgang Goethe-Universitat and Max-Planck-Institut fur Biophysik, Frankfurt am Main, FRG

**The Scientist. Analytical ultracentrifuges: a 'reinvention'. Scientist 6:22, 18, 20 (Nov. 8, 1992)

Optima XL-A applications described by Preston Hensley, Allen Minton and Howard Schachman

**Stafford, W. F., III. Boundary analysis in sedimentation transport experiments: a procedure for obtaining sedimentation coefficient distributions using the time derivative of the concentration profile. Anal. Biochem. 203, 295-301 (1992)

Model E, interference optics, sed. vel., g*(s); antigen-antibody complex; computation procedure for obtaining sedimentation coefficient distributions from the time derivative of the sedimentation velocity concentration profile; increases signal-to-noise ratio > 10-fold

**Stafford, W. F., III. Methods for obtaining sedimentation coefficient distributions. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 359-393. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Data acquisition and computations for g*(s) determination; extrapolation procedures for one-, two-, and four-component systems; Dept. Muscle Research, Boston Biomedical Research Institute, 20 Staniford Street, Boston, MA 02114

**Stafford, W. F., III. Boundary analysis in sedimentation velocity experiments. Methods in Enzymology, Vol. 240, pp. 478-501. Edited by M. L. Johnson and L. Brand. San Diego, Academic Press, 1994.

Optima XL-A, procedures for sedimentation velocity data analysis; g(s*); Analytical Centrifugation Research Laboratory, Boston Biomedical Research Institute, Boston, MA 02114

**Stafford, W. F., III. Sedimentation boundary analysis of interacting systems: use of the apparent sedimentation coefficient distribution function. Modern Analytical Ultracentrifugation, pp. 119-137. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Use of g(s*) determination; Analytical Centrifugation Research Laboratory, Boston Biomedical Research Institute, Boston, MA 02114

**Stafford, W. F., Liu, S. Methods for increasing the sensitivity of sedimentation velocity analysis: a signal averaging Rayleigh optical system for the Beckman Instruments Optima XL-A Analytical Ultracentrifuge. Proc. SPIE Int. Soc. Opt. Eng. 2386, 130-135 (1995)

Optima XL-A with video-based on-line Rayleigh interference optical system described; Analytical Centrifugation Research Laboratory, Boston Biomedical Research Institute, Boston, MA 02114

**Stafford, W. F., Schuster, T. M. Hydrodynamic methods. Introduction to Biophysical Methods for Protein and Nucleic Acid Research, pp. 111-145. Edited by J. A. Glasel and M. P. Deutscher. San Diego, Academic Press, 1995.

An introductory article discussing analytical ultracentrifugation, sucrose density gradient centrifugation and viscometry; no specific instruments mentioned; Boston Biomedical Research Institute, Boston, MA 02114

**Stafford, W. F., Liu, S., Prevelige, P. E. New high sensitivity sedimentation methods: application to the analysis of the assembly of bacteriophage P22. Techniques in Protein Chemistry, Vol. 6, pp. 427-434. Edited by J. W. Crabb. San Diego, Academic Press, 1995.

Optima XL-A with both absorption and video-based on-line interference optics, g(s*) vs. s*; bacteriophage P22 coat protein-bisANS dye interaction; Analytical Centrifugation Research Laboratory, Boston Biomedical Research Institute, Boston, MA 02114

**Steele, J. H. C., Jr., Tanford, C., Reynolds, J. A. Determination of partial specific volumes for lipid-associated proteins. Methods in Enzymology, Vol. 48, pp. 11-23. Edited by C. H. W. Hirs and S. N. Timasheff. New York, Academic Press, 1978.

**Steinmeier, D. Computer analysis of ultracentrifugation interference patterns. Progress in Colloid & Polymer Science, Vol. 94, pp. 116-119. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Computer program for analysis of digitized interferograms; Univ. of Osnabruck, FRG

**Suzuki, H. Sedimentation analysis of synthetic polymers. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 568-592. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Theory for sedimentation velocity and sedimentation equilibrium studies of nonideal, polydisperse systems; Dept. of Bioengineering, Nagaoka Univ. of Technology, Nagaoka, Niigata-Ken 940-21, Japan

**Teller, D. C., Swanson, E., De Haen, C. The translational friction coefficient of proteins. Methods in Enzymology, Vol. 61, pp. 103-124. Edited by C. H. W. Hirs and S. N. Timasheff. New York, Academic Press, 1979.

**Voelker, P., McRorie, D. alpha-Chymotrypsin: characterization of a self-associating system in the analytical ultracentrifuge. Technical Information T-1782A. Fullerton, Calif., Beckman Instruments, Inc., 1994.

Optima XL-A, sed. equil., K; alpha-chymotrypsin self-association; effect of concentration; Beckman Instruments, Inc., 1050 Page Mill Rd., Palo Alto, CA 94304

**Waxman, E., Laws, W. R., Laue, T. M., Ross, J. B. A. Refining hydrodynamic shapes of proteins: the combination of data from analytical ultracentrifugation and time-resolved fluorescence anisotropy decay. Modern Analytical Ultracentrifugation, pp. 189-205. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Hydrodynamic parameter calculation; Dept. of Biochemistry, Mount Sinai School of Medicine of the City of Univ. of New York, New York 10029

**Williams, J. W., Van Holde, K. E., Baldwin, R. L., Fujita, H. The theory of sedimentation analysis. Chem. Rev. 58, 715-806 (1958)

**Wills, P. R., Winzor, D. J. Thermodynamic non-ideality and sedimentation equilibrium. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 311-330. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Sedimentation equilibrium theory of nonideal solutions; virial and activity coefficients; interacting systems; (Wills) Dept. of Physics, Univ. of Auckland, Auckland, New Zealand

**Wills, P. R., Comper, W. D., Winzor, D. J. Thermodynamic nonideality in macromolecular solutions: interpretation of virial coefficients. Arch. Biochem. Biophys. 300, 206-212 (1993)

(Winzor) Dept. of Biochemistry, Univ. of Queensland, Brisbane, Queensland 4072, Australia

**Winzor, D. J., Wills, P. R. The omega analysis and the characterization of solute self-association by sedimentation equilibrium. Modern Analytical Ultracentrifugation, pp. 66-80. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Sedimentation equilibirum data analysis; Dept.of Biochemistry, Univ. of Queensland, Queensland 4072, Australia

**Yphantis, D. A. Equilibrium ultracentrifugation of dilute solutions. Biochemistry 3, 297-317 (1964)

**Yphantis, D. A., Waugh, D. F. Ultracentrifugal characterization by direct measurement of activity. I. Theoretical. J. Phys. Chem 60, 623-629 (1956)

**Yphantis, D. A., Lary, J. W. Modern equilibrium ultracentrifugation: applications of automated interferometry. Proc. SPIE Int. Soc. Opt. Eng. 2136, 193-204 (1994)

Model E with automated interference optics; methodology and data analysis described; Dept. of Molecular and Cell Biology and National Analytical Ultracentrifuge Facility, Univ. of Connecticut, Storrs, CT 06269-3125

**Yphantis, D. A., Lary, J. W., Stafford, W. F., Liu, S., Olsen, P. H., Hayes, D. B., Moody, T. P., Ridgeway, T. M., Lyons, D. A., Laue, T. M. On line data acquisition for the Rayleigh interference optical system of the analytical ultracentrifuge. Modern Analytical Ultracentrifugation, pp. 209-226. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Model E with conventional and low-magnification interference optics; Dept. of Molecular & Cell Biology and Analytical Ultracentrifugation Facitlity, Univ. of Connecticut, 75 North Eagleville Road, Storrs, CT 06269

Glycoproteins and Proteoglycans

**Borza, D.-B., Tatum, F. M., Morgan, W. T. Domain structure and conformation of histidineñproline-rich glycoprotein. Biochemistry 35, 1925-1934 (1996)

Optima XL-A, sed. vel., S; rabbit plasma histidineñproline-rich glycoprotein and histidineñproline-rich domain; An-60, 40 or 55 krpm, 233 nm, 20 or 25deg.C; effect of pH; CD, PAGE and far UV spectroscopy also used; (Morgan) Div. of Molecular Biology and Biochemistry, School of Biological Sciences, Univ. of Missouri-Kansas City, Kansas City, MO 64110

**Gane, A. M., Craik, D., Munro, S. L. A., Howlett, G. J., Clarke, A. E., Bacic, A. Structural analysis of the carbohydrate moiety of arabinogalactan-proteins from stigmas and styles of Nicotiania alata. Carbohydr. Res. 277, 67-85 (1995)

Optima XL-A, sed. equil., m; Nicotiana alata arabinogalactan-proteins; 5 krpm, 230 nm, 20deg.C; gel filtration and NMR also used; (Bacic) Plant Cell Biology Research Ctr., School of Botany, Univ. of Melbourne, Parkville, Victoria 3052, Australia

**Harding, S. E. Sedimentation equilibrium analysis of glycopolymers. Progress in Colloid & Polymer Science, Vol. 94, pp. 54-65. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Overview of sedimentation equilibrium methods for determining molar mass of glycoconjugates and polysaccharides using schlieren or interference optics; Univ. of Nottingham, School of Agriculture, Sutton Bonington, UK

**Liu, J., Laue, T. M., Choi, H. U., Tang, L.-H., Rosenberg, L. The self-association of biglycan from bovine articular cartilage. J. Biol. Chem. 269, 28366-28373 (1994)

Optima XL-A with interference optics, sed. vel., g (s*); Model E with schlieren optics, sed. vel., S; Model E with interference optics, sed. equil., M(z); effect of concentration and GuHCl on state of association; beef cartilage dermatan sulfate proteoglycan; (Laue) Dept. Biochem. and Mol. Biol., Univ. of New Hampshire, Durham, NH 03824

**Shire, S. J. Determination of molecular weight of glycoproteins by analytical ultracentrifugation. Technical Information DS-837. Palo Alto, Calif., Beckman Instruments, Inc., Spinco Business Unit, 1992.

Optima XL-A, sed. equil., M; recombinant HIV-1 envelope glycoprotein, human tumor necrosis factor receptor; 10 krpm and 280 nm or 15 krpm, 232 nm, 20 ; Dept. of Pharmaceutical R&D, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Shire, S. J. Analytical ultracentrifugation and its use in biotechnology. Modern Analytical Ultracentrifugation, pp. 261-297. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A, sed. equil., M; recombinant HIV-1 envelope glycoprotein, recombinant apolipoprotein A, and human tumor necrosis factor type 1 receptor and its TNF-alpha complex; 5, 10 or 15 krpm; Dept. of Pharmaceutical R&D, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Zhuang, P., Blackburn, M. N., Peterson, C. B. Characterization of the denaturation and renaturation of human plasma vitronectin. I. Biophysical characterization of protein unfolding and multimerization. J. Biol. Chem. 271, 14323-14332 (1996)

Optima XL-A, sed. equil., M(r), state of oligomerization; sed. vel., S; human plasma vitronectin and multimers; 10-20 krpm (s.e), 60 krpm (s.v.); 280 nm, 20deg.C; effect of urea or GuHCl; CD and fluorescence also used; (Peterson) M407 Walters Life Sciences Bldg., Dept. of Biochemistry and Cellular and Molecular Biology, Univ. of Tennessee, Knoxville, TN 37996

Lipoproteins

**Fless, G. M., Snyder, M. L., Furbee, J. W., Jr., Garcia-Hedo, M.-T., Mora, R. Subunit composition of lipoprotein(a) protein. Biochemistry 33, 13492-13501 (1994)

Optima XL-A, sed. equil., b.d., M(r); human plasma LDL, lipoprotein(a), reduced and carboxymethylated of apolipoproteins(a) and -(b), and apoB-apo(a) complex; 3-10 krpm, density adjusted with NaBr; GuHCl; (Fless) Dept. of Medicine, Univ. of Chicago, 5841 S. Maryland Ave., Chicago, IL 60637

**Fless, G. M., Furbee, J., Jr., Snyder, M. L., Meredith, S. C. Ligand-induced conformational change of lipoprotein(a). Biochemistry 35, 2289-2298 (1996)

Optima XL-A, sed. equil. in NaBr, M(r), v-bar; sed. vel., D, f/f(0), K(d), R(s), S; human LDL, Lp(a), and Lp(a-)ñ6-aminohexanoic acid complexes; rhesus monkey Lp(a) and its 6-AHA complex; An-60 Ti; 40 krpm (s.v.), 3500 rpm (diff.), 220 or 280 nm; effect of concentration; PAGE also used; Dept. of Medicine, Univ. of Chicago, 5841 S. Maryland Ave., Chicago, IL 60637

**Kawabe, Y., Cynshi, O., Takashima, Y., Suzuki, T., Ohba, Y., Kodama, T. Oxidation-induced aggregation of rabbit low-density lipoprotein by azo initiator. Arch. Biochem. Biophys. 310, 489-496 (1994)

Optima XL-A, sed. vel., S; rabbit oxidized, aggregated or monomeric, or acetylated low density lipoproteins; XL-80, AN-60 Ti, 10 or 50 krpm, 280 nm; LS & GPC also used; (Cynshi) Fujigotemba Research Laboratories Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba-shi, Shizuoka 412, Japan

Miscellaneous Samples (Including Peptides)

**Atkins, A. R., Martin, R. C., Smith, R. (1)H NMR studies of sarafotoxin SRTb, a nonselective endothelin receptor agonist, and IRL 1620, an ET(B) receptor-specific agonist. Biochemistry 34, 2026-2033 (1995)

Optima XL-A, sed. equil., state of association; receptor-specific agonist peptide; 60 krpm, 280 & 360 nm, 7 & 20deg.C; NMR & CD also; Biochemistry Dept., Univ. of Queensland, Queensland 4072, Australia

**Betz, S. F., DeGrado, W. F. Controlling topology and native-like behavior of de novo-designed peptides: design and characterization of antiparallel four-stranded coiled coils. Biochemistry 35, 6955-6962 (1996)

Optima XL-A, sed, equil., delta G, K; synthetic coiled-coil peptides; 35, 42 and 48 krpm; CD, fluorescence and NMR also used; (DeGrado) The Johnson Research Foundation, Dept. of Biochemistry and Biophysics, Univ. of Pennsylvania, Philadelphia, PA 19104-6059

**Blacklow, S. C., Lu, M., Kim, P. S. A trimeric subdomain of the simian immunodeficiency virus envelope glycoprotein. Biochemistry 34, 14955-14962 (1995)

Optima XL-A, sed. equil., m, state of oligomerization; recombinant SIV envelope glycoprotein domain peptides and their trimeric complex; An-60 Ti, 13-20 krpm, 20deg.C, CD also used; (Kim) Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Dept. of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142

**Blanco, F. J., Rivas, G., Serrano, L. A short linear peptide that folds into a native stable beta-hairpin in aqueous solution. Nature, Struct. Biol. 1, 584-590 (1994)

Optima XL-A, sed. equil., M(w); synthetic 16-residue peptide monomer; An-60 Ti, 40 krpm; CD, NMR & SEC also used; (Blanco) EMBL, Postfach 102209, Meyerhofstrasse 1, 69012 Heidelberg, Germany

**Carr, C. M., Kim, P. S. A spring-loaded mechanism for the conformational change of influenza hemagglutinin. Cell 73, 823-832 (1993)

Optima XL-A, sed. equil., M; synthetic coiled-coil peptide corresponding to influenza virus hemagglutinin peptide; 22 & 27 krpm, pH 7.2 & 4.7; Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Dept. of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142

**C^lfen, H., Harding, S. E.. A study on Schlieren patterns derived with the Beckman Optima XL-A UV-absorption optics. Progress in Colloid & Polymer Science, Vol. 99, pp. 167-186. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A, sed. vel., schlieren effect derived with absorption optics used to examine various polysaccharides: chitosan, kappa-carrageenan, Na-alginate, dextrans 20 and 150, and xanthan; 12.6-60 krpm, 20deg.C, 276-600 nm; results compared to Model E with schlieren optics; Max-Planck-Inst. for Colloid and Interface Research, Colloid Chemistry Dept., Kantstrasse 55, 14513 Teltow, Germany

**Dhami, R., C^lfen, H., Harding, S. E. A comparative "Schlieren" study of the sedimentation behaviour of three polysaccharides using the Beckman Optima XL-A and Model E analytical ultracentrifuges. Progress in Colloid & Polymer Science, Vol. 99, pp. 187-192. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A schlieren effect results compared with Model E schlieren results, sed. vel., K(s), S; polysaccharides: arabinoxylan, xanthan and locust bean gum; 30 or 60 krpm, 200-600 nm, 20deg.C; (Harding) Natl. Ctr. for Macromolecular Hydrodynamics, Univ. of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK

**Dhami, R., Harding, S. E., Elizabeth, N. J., Ebringerova, A. Hydrodynamic characterisation of the molar mass and gross conformation of corn cob heteroxylan AGX. Carbohydr. Polym. 28, 113-119 (1995)

Optima XL-A used to obtain schlieren diagrams, sed. vel., S; Model E, interference optics, sed. equil., M(w); MSE MkII analytical ultracentrifuge, schlieren optics, sed. equil., M(z); corn cob heteroxylan; 60 krpm (s.v.); 440 nm used for schlieren method; 20deg.C; 6000 rpm (s.e.), 20deg.C; viscometry also used; Univ. of Nottingham, Natl. Ctr. for Macromolecular Hydrodynamics, Dept. of Applied Biochemistry and Food Science, Sutton Bonington, LE12 5RD, UK

**Digard, P., Williams, K. P., Hensley, P., Brooks, I. S., Dahl, C. E., Coen, D. M. Specific inhibition of herpes simplex virus DNA polymerase by helical peptides corresponding to the subunit interface. Proc. Natl. Acad. Sci. 92, 1456-1460 (1995)

Optima XL-A, sed. equil., m, v-bar; synthetic DNA polymerase catalytic subunit 36-residue peptide; 50 or 60 krpm, 230 nm; H(2)O or D(2)O; CD also used; (Coen) Dept. of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115

**D^beli, H., Draeger, N., Huber, G., Jakob, P., Schmidt, D., Seilheimer, B., Stuber, D., Wipf, B., Zulauf, M. A biotechnological method provides access to aggregation competent monomeric Alzheimer's 1-42 residue amyloid peptide. Bio/Technology 13, 988-993 (1995)

Optima XL-A, sed. equil., m; recombinant Alzheimer's beta-amyloid peptide; 40 krpm; CD, mass spectrometry, PAGE and size exclusion chromatography also used; Pharma Division, Preclinical Research, F. Hoffmann-La Roche, CH-4002 Basel, Switzerland

**Fairman, R., Chao, H.-G., Mueller, L., Lavoie, T. B., Shen, L., Novotny, J., Matsueda, G. R. Characterization of a new four-chain coiled-coil: influence of chain length on stability. Protein Sci. 4, 1457-1469 (1995)

Optima XL-A, sed. equil., state of oligomerization; synthetic coiled-coil peptide monomers-tetramers; An-60 Ti, 20, 30, and 40 krpm, 240 nm, 25deg.C; CD and gel filtration also used; effect of speed; Div. of Macromolecular Structure, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ, 08543-4000

**Fairman, R., Chao, H.-G., Lavoie, T. B., Villafranca, J. J., Matsueda, G. R., Novotny, J. Design of heterotetrameric coiled coils: evidence for increased stabilization by Gly(-)-Lys(+) ion pair interactions. Biochemistry 35, 2824-2829 (1996)

Optima XL-A, sed. equil., M, state of oligomerization; synthetic coiled-coil peptides and heterotetramers; An-60 Ti, 30, 40 and 50 krpm, 242 nm, 25deg.C; CD also used; Div. of Macromolecular Structure, Bristol-Myers Squibb Pharmaceutical Research inst., P.O. 4000, Princeton, NJ 08543-4000

**Farr, C. D., Galiano, F. J., Witt, S. N. Large activation energy barriers to chaperone-peptide complex formation and dissociation. Biochemistry 34, 15574-15582 (1995)

Optima XL-A, sed. equil., M, state of association; dansylated and unlabeled synthetic Cro repressor protein peptides; 40 krpm, 275 and 335 nm, 25deg.C; fluorescence and SEC also used; (Witt) Dept. of Biochemistry and Molecular Biology, Louisiana State Univ. Medical Center, 1501 Kings Highway, Shreveport, LA 71130-3932

**Fletcher, T. M., Hansen, J. C. Core histone tail domains mediate oligonucleosome folding and nucleosomal DNA organization through distinct molecular mechanisms. J. Biol. Chem. 270, 25359-25362 (1995)

Optima XL-A, sed. vel., S; chicken erythrocyte trypsinized nucleosomal arrays; effect of MgCl(2) concentration; (Hansen) Dept. of Biochemistry, Univ. of Texas Health Science Center, 7703 Floyd Curl Dr., San Antonio, TX 78284-7760

**Fletcher, T. M., Krishnan, U., Serwer, P., Hansen, J. C. Quantitative agarose gel electrophoresis of chromatin: nucleosome-dependent changes in charge, shape, and deformability at low ionic strength. Biochemistry 33, 2226-2233 (1994)

Optima XL-A, sed. vel., s distribution; chicken erythrocyte nucleosomal arrays; An-60 Ti, 18-28 krpm; (Hansen) Dept. of Biochemistry, The Univ. of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-7760

**Fletcher, T. M., Serwer, P., Hansen, J. C. Quantitative analysis of macromolecular conformational changes using agarose gel electrophoresis: application to chromatin folding. Biochemistry 33, 10859-10863 (1994)

Optima XL-A, sed. vel., S; DNA and nucleosomal arrays; Dept. of Biochemistry, Univ. of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-7760

**Germeroth, L., Lottspeich, F., Robert, B., Michel, H. Unexpected similarities of the B800-850 light-harvesting complex from Rhodospirillum molischianum to the B870 light-harvesting complexes from other purple photosynthetic bacteria. Biochemistry 32, 5615-5621 (1993)

Optima XL-A (inferred), sed. equil., M; bacteria light-harvesting complex II (B800/850); no exptl. details; SDS-PAGE also used; Michel) Max-Planck-Institut fur Biophysik, Abteilung Molekulare Membranbiologie, 6000 Frankfurt, FRG

**Gibbons, D. L., Horowitz, P. M. Exposure of hydrophobic surfaces on the chaperonin GroEL oligomer by protonation or modification of His-401. J. Biol. Chem. 270, 7335-7340 (1995)

Optima XL-A, sed. vel., S; recombinant chaperonin GroEL oligomer; An-60 Ti, 20 or 27 krpm, effect of pH 5.5; fluorescence also used; 14-mer; Dept. of Biochemistry, Univ. of Texas Health Science Center, San Antonio, TX 78284-7760

**Giordano, T., Pan, J. B., Monteggia, L. M., Holzman, T. F., Snyder, S. W., Krafft, G., Ghanbari, H., Kowall, N. W. Similarities between beta amyloid peptides 1-40 and 40-1: effects on aggregation, toxicity in vitro, and injection in young and aged rats. Exp. Neurol. 125, 175-182 (1994)

Optima XL-A, sed. vel., aggregation detected and related to toxicity; synthetic beta-amyloid peptides; 30 krpm; (Giordano) Abbott Laboratories, Dept. of Neuroscience, Abbott Park, IL 60064

**Gonzalez, L., Jr., Plecs, J. J., Alber, T. An engineered allosteric switch in leucine-zipper oligomerization. Nat. Struct. Biol. 3, 510-515 (1996)

Optima XL-A, sed. equil., M(r), state of oligomerization; coiled-coil leucine zipper peptides and ligand complexes; 50 krpm, 235 and 220 nm, 5deg.C and 25deg.C; effect of benzene; CD also used; (Alber) Dept. of Molecular and Cell Biology, 229 Stanley Hall, Univ. of California, Berkeley, CA 94720-3206

**Hansen, J. C., Wolffe, A. P. A role for histones H2A/H2B in chromatin folding and transcriptional repression. Proc. Natl. Acad. Sci. 91, 2339-2343 (1994)

Optima XL-A, sed. vel., s distributions; reconstituted nucleosomal arrays; effect of Mg(2+) concentration; (Hansen) Dept. of Biochemistry, Univ. of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78284-7760

**Harbury, P. B., Zhang, T., Kim, P. S., Alber, T. A switch between two-, three-, and four-stranded coiled coils in GCN4 leucine zipper mutants. Science 262, 1401-1407 (1993)

Optima XL-A, sed. equil., M; effect of pH and concentration on synthetic coiled-coil peptides; An-60 Ti, various rotor speeds; (Alber) Dept. of Molecular and Cell Biology, Univ. of California, Berkeley, CA 94720

**Harding, S. E. Sedimentation equilibrium analysis of glycopolymers. Progress in Colloid & Polymer Science, Vol. 94, pp. 54-65. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Overview of sedimentation equilibrium methods for determining molar mass of glycoconjugates and polysaccharides using schlieren or interference optics; Univ. of Nottingham, School of Agriculture, Sutton Bonington, UK

**Harding, S. E. Some recent developments in the size and shape analysis of industrial polysaccharides in solution using sedimentation analysis in the analytical ultracentrifuge. Carbohydr. Polym. 28, 227-237 (1995)

Overview of sedimentation equilibrium and velocity methods, and review of applications; Optima XL-I mentioned; Univ. of Nottingham, Dept. of Applied Biochemistry and Food Science, Sutton Bonington LE12 5RD, UK

**Hedges, J., Sarrafzadeh, S., Lear, J. D., McRorie, D. K. Extensions to commercial graphics packages for customization of analysis of analytical ultracentrifuge data. Modern Analytical Ultracentrifugation, pp. 227-244. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A data analysis using extended Originô (MicroCal Software, Inc.) software; examples of sedimentation equilibrium data analysis of coiled-coil Trp peptide given; Beckman Instruments, Inc., 1050 Page Mill Road, Palo Alto, CA 94304

**Joslyn, G., Richardson, D. S., White, R., Alber, T. Dimer formation by an N-terminal coiled coil in the APC protein. Proc. Natl. Acad. Sci. 90, 11109-11113 (1993)

Optima XL-A, sed. equil., M(r); familial adenomatous polyposis APC gene product coiled-coil peptides; 235 or 280 nm; (Alber) Dept. of Molecular and Cell Biology, Stanley/Donner ASU, Univ. of California, Berkeley, CA 94720

**Kojima, S., Kuriki, Y., Sato, Y., Arisaka, F., Kumagai, I., Takahashi, S., Miura, K. Synthesis of alpha-helix-forming peptides by gene engineering methods and their characterization by circular dichroism spectra measurements. Biochim. Biophys. Acta 1294, 129-137 (1996)

Optima XL-A, sed. equil., M, state of oligomerization; recombinant alpha-helix-forming peptides; An-60 Ti, 20 krpm, 230 nm, 20deg.C; CD and gel filtration also used; state of oligomerization; (Miura) Inst. for Biomolecular Science, Gakushuin Univ., Mejiro, Tokyo 171, Japan

**Lewis, M. S., Shrager, R., Kim, S. J. Ultracentrifugal analysis of protein-nucleic acid interactions using multi-wavelength scans. Progress in Colloid & Polymer Science, Vol. 94, pp. 46-53. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil., absorbancy distributions at multiple wavelengths; Drosophila heat shock factor polypeptide, synthetic oligodeoxynucleotide and their interaction; 230-246, 260 & 280 nm; (Lewis) Biomedical Engineering and Instrumentation Program, National Center for Research Resources, Bethesda, MD

**Linsdell, H., Toiron, C., Bruix, M., Rivas, G., Menendez, M. Dimerization of A82846B, vancomycin and ristocetin: influence on antibiotic complexation with cell wall model peptides. J. Antibiot. 49, 181-193, (1996)

Optima XL-A, sed. equil., K; glycopeptide antibiotics A82846B, vancomycin and ristocetin and their cell wall model peptide complexes; 40 krpm; 240, 280 and 300 nm; 25deg.C; NMR also used; Instituto "Rocasolano", Serrano 119, Spain

**Lovejoy, B., Choe, S., Cascio, D., McRorie, D. K., DeGrado, W. F., Eisenberg, D. Crystal structure of a synthetic triple-stranded alpha-helical bundle. Science 259, 1288-1293 (1993)

Optima XL-A, sed. equil., m; synthetic coil-Ser peptide; 30 krpm; Mol. Biol. Inst. & Dept. of Chemistry & Biochemistry, Univ. California at Los Angeles; Beckman Instruments, Palo Alto; Biotechnolgy Dept., DuPont Merck Pharmaceuticals Co., Wilmington, DE

**Montoya, G., Cyrklaff, M., Sinning, I. Two-dimensional crystallization and preliminary structure analysis of light harvesting II (B800-850) complex from the purple bacterium Rhodovulum sulfidophilum. J. Mol. Biol. 250, 1-10 (1995)

Optima XL-A, sed. equil., M(r); sed. vel., state of association; bacterial light harvesting II complex; 14 krpm (s.e.), 56 krpm (s.v.), 275 or 367 nm, 20deg.C; 1% octyl-POE as detergent; PAGE and gel filtration also used; (Sinning) European Molecular Biology Laboratory, Meyarhofstrasse 1 69012 Heidelberg, Germany

**Nautiyal, S., Woolfson, D. N., King, D. S., Alber, T. A designed heterotrimeric coiled coil. Biochemistry 34, 11645-11651 (1995)

Optima XL-A, sed. equil., m; synthetic peptides and their heterotrimeric coiled coil; 20 and 30 krpm; 229, 276 and 285 nm; 10deg.C; CD and PAGE also used; (Alber) Dept. of Molecular and Cell Biology, 229 Stanley Hall, Univ. of California, Berkeley, CA 94720-3206

**Merutka, G., Morikis, D., Bruschweiler, R., Wright, P. E. NMR evidence for multiple conformations in a highly helical model peptide. Biochemistry 32, 13089-13097 (1993)

Optima XL-A, sed. equil., m; synthetic helical peptide; 35 krpm, 276 nm, CD & NMR also used; worked performed by Paul Voelker, Beckman; Dept. of Molecular Biology, The Scripps Research Institute, 10666 North Torrey Road, La Jolla, CA 92037

**Mills, R. G., Ralston, G. B., King, G. F. The solution structure of sarafotoxin-c. Implications for ligand recognition by endothelin receptors. J. Biol. Chem. 269, 23413-23419 (1994)

Optima XL-A, sed. equil., m, associative state; synthetic sarafotoxin-c peptide monomer; 30-40 krpm, 280 nm, effect of conc.; "oligomeric state necessary for NMR studies"; Dept. of Biochemistry, Univ. of Sydney, Sydney, New South Wales 2006, Australia

**Moore, K. L., Eaton, S. F., Lyons, D. E., Lichenstein, H. S., Cummings, R. D., McEver, R. P. The P-selectin glycoprotein ligand from human neutrophils displays sialylated, fucosylated, O-linked poly-N-acetyllactosamine. J. Biol. Chem. 269, 23318-23327 (1994)

Optima XL-A, interference optics, sed. equil., m, sed. vel., S; recombinant truncated soluble E-selectin monomer; 10-25 krpm (s.e.), 60 krpm (s.v.), prototype optics at Univ. of New Hampshire; effect of concentration; axial ratio; (Moore) Dept. of Medicine, Univ. of Oklahoma Health Sciences Center, 825 N. E. 13th St., Oklahoma City, OK 73014

**Morris, M. B., Ralston, G. B., Biden, T. J., Browne, C. L., King, G. F., Iismaa, T. P. Structural and biochemical studies of human galanin: NMR evidence for nascent helical structures in aqueous solution. Biochemistry 34, 4538-4545 (1995)

Optima XL-A, sed. equil., m; synthetic human galanin monomer; 30 krpm, 280, 300 & 360 nm; 20deg.C; CD and NMR also used; 30-residue neuropeptide; Dept. of Biochemistry, Univ. of Sydney, Sydney, Australia

**Muhle-Goll, C., Gibson, T., Schuck, P., Schubert, D., Nalis, D., Nilges, M., Pastore, A. The dimerization stability of the HLH-LZ transcription protein family is modulated by the leucine zippers: a CD and NMR study of TFEB and c-Myc. Biochemistry 33, 11296-11306 (1994)

Optima XL-A, sed. equil., state of association; synthetic TFEB transcription activator protein leucine zipper peptide monomer-dimer; 40 krpm, 4deg.C, 275 nm; (Muhle-Goll) EMBL, Meyerhofstrasse 1, D-69117 Heidelberg, Germany

**Mulhern, T. D., Howlett, G. J., Reid, G. E., Simpson, R. J., McColl, D. J., Anders, R. F., Norton, R. S. Solution structure of a polypeptide containing four heptad repeat units from a merozoite surface antigen of Plasmodium falciparum. Biochemistry 34, 3479-3491 (1995)

Optima XL-A, sed. equil., m; synthetic antigen SPAM monomer; 20, 35 & 40 krpm; 230, 240, 245 & 290 nm; effect of concentration; 38-residue peptide; D(2)O; NMR also; (Norton) Dept. of Medicine, Univ. of Queensland, Princess Alexandra Hospital, Queensland 4102, Australia

**Musco, G., Tziatzios, C., Schuck, P., Pastore, A. Dissecting titin into its structural motifs: identification of an alpha-helix motif near the titin N-terminus. Biochemistry 34, 553-561 (1995)

Optima XL-A, sed. equil., state of association; synthetic titin (connectin) coiled-coil peptide monomer-tetramer; An-60 Ti, 35 & 25 krpm, 275 nm; 38-residues; CD & NMR also; effect of pH & salt conc.; EMBL, Meyerhofstrasse 1, W-69012 Heidelberg, Germany

**Myszka, D. G., Chaiken, I. M. Design and characterization of an intramolecular antiparallel coiled coil peptide. Biochemistry 33, 2363-2372 (1994)

Optima XL-A, sed. equil., m; synthetic coiled-coil stem loop peptide; 40 krpm, 235 nm, 4deg.C; used to confirm monomer m determined by gel/filtration; CD & MS also used; SmithKline Beecham Research and Development, 709 Swedeland Road, UE0548, King of Prussia, PA 19406-2799

**Needham, G. F., Pekar, A. H., Havel, H. A. Effect of salts on the structure of a potent analog of growth hormone releasing hormone as determined by optical spectroscopy. J. Pharm. Sci. 84, 437-442 (1995)

Optima XL-A, sed. equil., effect of urea on state of association; synthetic growth hormone analog; An-60 Ti, 22 krpm, 280 nm, 22deg.C; effect of urea; CD and light scattering also used; Eli Lilly and Co., P.O. B. 708 Greenfield, IN 46140

**O'Shea, E. K., Lumb, K. J., Kim, P. S. Peptide 'Velcro': design of a heterodimeric coiled coil.

Curr. Biol. 3, 658-667 (1993)

Optima XL-A, sed. equil., state of association; synthetic leucine zipper region coiled-coil peptide heterodimers; 30-40 krpm; CD & NMR also used; (Kim) Dept. of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142

**Rabenstein, M., Shin, Y.-K. A peptide from the heptad repeat of human immunodeficiency virus gp41 shows both membrane binding and coiled-coil formation. Biochemistry 34, 13390-13397 (1995)

Optima XL-A, sed, equil., m, state of oligomerization; HIV envelope glycoprotein coiled-coil peptide; 40 krpm, effect of concentration; CD and EPR also used; (Shin) Dept. of Chemistry, Univ. of California, Berkeley, CA 94720

**Sabharwal, A. K., Birktoft, J. J., Gorka, J., Wildgoose, P., Petersen, L. C., Bajaj, S. P. High affinity Ca(2+)-binding site in the serine protease domain of human factor VIIa and its role in tissue factor binding and development of catalytic activity. J. Biol. Chem. 270, 15523-15530 (1995)

Optima XL-A, sed. equil., M(r); synthetic human Factor VIIa peptide; 40 krpm, 22deg.C, 280 nm; effect of salt; CD and PAGE also used; (Bajaj) St. Louis Univ. Health Sciences Ctr., 3635 Vista Ave., P.O. Box 15250, St. Louis, MO 63110-0250

**Sakamoto, H., Lewis, M. S., Kodama, H., Appella, E., Sakaguchi, K. Specific sequences from the carboxyl terminus of human p53 gene product form anti-parallel tetramers in solution. Proc. Natl. Acad. Sci. 91, 8974-8978 (1994)

Optima XL-A, sed. equil., K(D), delta G; synthetic p53 gene product peptides association; 24-32 krpm, 5-33deg.C, 231 nm; (Appella) Laboratory of Cell Biology, National Cancer Institute, Bldg. 37, Room 1B10, Bethesda, MD 20892

**Schubert, D., Tziatzios, C., van den Broek, J. A., Schuck, P., Germeroth, L., Michel, H. Determination of the molar mass of pigment-containing complexes of intrinsic membrane proteins: problems, solutions and application to the light-harvesting complex B800/820 of Rhodospirillum molischianum Progress in Colloid & Polymer Science, Vol. 94, pp. 14-19. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil, m,v-bar; Rhodospirillum molischianum light harvesting protein-pigment complex oligomers in various detergent solutions; 15-25 krpm, 357 or 370 nm, 6deg.C; Institut fur Biophysik, JWG-Universitat, Frankfurt am Main, FRG

**Schwartz, P. M., Felthauser, A., Fletcher, T. M., Hansen, J. C. Reversible oligonucleosome self-association: dependence on divalent cations and core histone tail domains. Biochemistry 35, 4009-4015 (1996)

Optima XL-A, sed. vel., S, state of association; chicken erythrocyte oligonucleosomes; 4-28 krpm; effect of Mg(2+) ion; (Hansen) Dept. of Biochemistry, Univ. of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78284-7760

**Schwarz, P. M., Hansen, J. C. Formation and stability of higher order chromatin structures. Contributions of the histone octamer. J. Biol. Chem. 269, 16284-16289 (1994)

Optima XL-A, sed. equil., m; sed. vel., S; Model E with Scanner, sed. vel., S; chicken erythrocyte chromatin oligonucleosomes; Dept. of Biochemistry, Univ. of Texas Health Science Center, San Antonio, TX 78284-7760

**Snyder, S. W., Ladror, U. S., Wade, W. S., Wang, G. T., Barrett, L. W., Matayoshi, E. D., Huffaker, H. J., Krafft, G. A., Holzman, T. F. Amyloid-beta aggregation: selective inhibition of aggregation in mixtures of amyloid with different chain lengths. Biophys. J. 67, 1216-1228 (1994)

Optima XL-A, sed. equil., m, sed. vel., S, g*(s); aggregation state; synthetic amyloid-beta 39-43 residue peptide; An-60 Ti, 3000-60 krpm (s.e.), 1000-30,000 krpm; dynamic light scattering & turbidity also used; effect of solvents; oil deposits on optics; (Holzman) D-46Y, AP-10, Protein Biochemistry, Pharmaceutical Discovery Research, Abbott Laboratories, 1 Abbott Park Road, Abbott Park, IL 60064-3500

**Terzi, E., H^lzemann, G., Seelig, J. Reversible random coilñbeta-sheet transition of the Alzheimer beta-amyloid fragment (25-35). Biochemistry 33, 1345-1350 (1994)

Optima XL-A, sed. equil., m; synthetic beta-amyloid peptide; An-60 Ti, 56 krpm; CD also used; Dept. of Biophysical Chemistry, Biocenter of the Univ. of Basel, Klingelbergstrsse 70, CH-4056 Basel, Switzerland

**Terzi, E., H^lzemann, G., Seelig, J. Self-association of beta-amyloid peptide (1-40) in solution and binding to lipid membranes. J. Mol. Biol. 252, 633-642 (1995)

Optima XL-A, sed. equil., degree of association, m; commercial beta-amyloid peptide (Alzheimer peptide); 8 or 52 krpm; CD and calorimetry also used; (Seelig) Dept. of Biophysical Chemistry, Biocenter of the Univ. of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland

**Thomas, R. M., Wendt, H., Zampieri, A., Bosshard, H. R. alpha-Helical coiled coils: simple models for self-associating peptide and protein systems. Progress in Colloid & Polymer Science, Vol. 99, pp. 24-30. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A, sed. equil., m; synthetic coiled-coil peptides; 21 krpm, 230 nm, 20deg.C; effect of concentration; CD also used; Institut fur Polymere, ETH-Zentrum, 8092 Zurich, Switzerland

**Tziatzios, C., Schuck, P., Schubert, D., Tsiotis, G. The molar mass of an active photosystem I complex from the cyanobacterium Synechococcus PCC 7002. Z. Naturforsch., C: Biosci. 49, 220-222 (1994)

Optima XL-A, sed. equil., M(r),v-bar; Synechococcus photosystem I complex (protein-pigment complex); D(2)O/D(2)(18) O method for v-bar; effect of three detergents; (Schubert) Institut fur Biophysik der J. W. Goethe-Universitat, Theodor-Stern, Kai 7, Hous 74, D-60590 Frankfurt am Main, Bundesrepublik Deutschland

**Wendt, H., Berger, C., Baici, A., Thomas, R. M., Bosshard, H. R. Kinetics of folding of leucine zipper domains. Biochemistry 34, 4097-4107 (1995)

Optima XL-A, sed. equil., m; synthetic leucine zipper coiled-coil peptides; 16-40 krpm, 20deg.C, FC43 false bottom; fluorescence & stopped-flow also used; Biochemisches Institut der Universitat Zurich, Winterhurerstrasse 190, CH-8057 Zurich, Switzerland

**Wendt, H., Durr, E., Thomas, R. M., Przybylski, M., Bosshard, H. R. Characterization of leucine zipper complexes by electrospray ionization mass spectrometry. Protein Sci. 4, 1563-1570 (1995)

Optima XL-A, sed. equil., m; degree of oligomerization; synthetic leucine zipper coiled coil peptides; 16-42 krpm, 20deg.C; number of strands determined; CD and mass spectrometry also used; (Bosshard) Biochemisches Institut der Universitat Zurich, CH-8057 Zurich, Switzerland

**Yoo, S. H., Lewis, M. S. Dimerization and tetramerization properties of the C-terminal region of chromogranin A: a thermodynamic analysis. Biochemistry 32, 8816-8822 (1993)

Model E with Scanner, Optima XL-A (240 nm), sed. equil., delta G, delta H, delta C, delta S; effect of pH and temperature (2-32deg.C); chromogranin A peptides monomer-dimer & monomer-tetramer equilibria; 30 krpm; CD also; (Yoo) Laboratory of Cellular Biology, NIDCD/NIH, Building 36, Room 5D-15, Bethesda, MD 20892

Nucleic Acids

**Clark, D. J., Ghirlando, R., Felsenfeld, G., Eisenberg, H. Effect of positive supercoiling on DNA compaction by nucleosome cores. J. Mol. Biol. 234, 297-301 (1993)

Optima XL-A, sed. vel., S plotted as a function of mean excess linking number (delta Lk); plasmid DNAs and reconstituted nucleosome cores; 24-25 krpm, 260 nm, Beckman XLAVEL data analysis; Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892

**Dolinnaya, N. G., Braswell, E. H., Fossella, J. A., Klump, H., Fresco, J. R. Molecular and thermodynamic properties of d(A(+)-G)(10), a single-stranded nucleic acid helix without paired or stacked bases. Biochemistry 32, 10263-10270 (1993)

Optima XL-A, sed. equil., B, M; deoxyoligonucleotide strand; 48, 52 or 40 krpm, FC43 used, 300 & 280 nm, fit to single-species ideal model; 4 or 40deg.C; (Fresco) Dept. of Molecular Biology, Princeton Univ., Princeton, NJ 08544-1014

**Fletcher, T. M., Serwer, P., Hansen, J. C. Quantitative analysis of macromolecular conformational changes using agarose gel electrophoresis: application to chromatin folding. Biochemistry 33, 10859-10863 (1994)

Optima XL-A, sed. vel., S; DNA and nucleosomal arrays; Dept. of Biochemistry, Univ. of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-7760

**Lewis, M. S., Shrager, R., Kim, S. J. Ultracentrifugal analysis of protein-nucleic acid interactions using multi-wavelength scans. Progress in Colloid & Polymer Science, Vol. 94, pp. 46-53. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil., absorbancy distributions at multiple wavelengths; Drosophila heat shock factor polypeptide, synthetic oligodeoxynucleotide and their interaction; 230-246, 260 & 280 nm; (Lewis) Biomedical Engineering and Instrumentation Program, National Center for Research Resources, Bethesda, MD

**Rohozinski, J., Hancock, J. M., Keniry, M. A. Polycytosine regions contained in DNA hairpin loops interact via a four-stranded, parallel structure similar to the i-motif. Nucleic Acids Res. 22, 4653-4659 (1994)

Optima XL-A, sed. equil., M(b), effect of pH on state of association; oligodeoxynucleotide and dimer; 40 krpm, 260 nm; CD & NMR also used; (Rohozinski) Research School of Biological Sciences , Australian National Univ., Canberra, ACT 0200, Australia

**Scaria, P. V., Shire, S. J., Shafer, R. H. Quadruplex structure of d(G(3)T(4)G(3)) stabilized by K(+) or Na(+) is an asymmetric hairpin dimer. Proc. Natl. Acad. Sci. 89, 10336-10340 (1992)

Optima XL-A, sed. equil., M; effect of ions on oligonucleotides; 40 krpm, also P/ACE; (Shafer) Dept. of Pharmaceutical Chemistry, School of Pharmacy, Univ. of California, San Francisco, CA 94143.

**Seifert, A., Heinevetter, L., C^lfen, H., Harding, S. E. Characterization of gliadin-galactomannan incubation mixtures by analytical ultracentrifugation. Part I. Sedimentation velocity. Carbohydr. Polym. 28, 325-332 (1995)

Optima XL-A, sed. equil., M(w); wheat gliadin and locust bean galactomannan; Model E and MOM 3170B analytical ultracentrifuge with schlieren optics, S; gliadin, galactomannan and their interaction; 10 and 15 krpm, 220 and 230 nm (XL-A); PAGE also used; German Institute for Human Nutrition, Arthur-Scheunert-Allee 114-116, D-14558 Bergholz-Rehbrucke, Germany

Proteins: Enzymes

**Artigues, A., Iriarte, A., Martinez-Carrion, M. Acid-induced reversible unfolding of mitochondrial aspartate aminotransferase. J. Biol. Chem. 269, 21990-21999 (1994)

Optima XL-A, sed. vel., S; effect of pH on mammalian mitochondrial aspartate aminotransferase unfolding; An-60 Ti, 6 krpm, 280 nm; CD, fluorescence, PAGE & IR also used; Division of Molecular Biology and Biochemistry, School of Biological Sciences, Univ. of Missouri, Kansas City, MO 64110-2499

**Behal, R. H., DeBuysere, M. S., Demeler, B., Hansen, J. C., Olson, M. S. Pyruvate dehydrogenase multienzyme complex. Characterization of assembly intermediates by sedimentation velocity analysis. J. Biol. Chem. 269, 31372-31377 (1994)

Optima XL-A, sed. vel., S distribution; beef heart pyruvate dehydrogenase multienzyme complex E2-X subcomplex (dissociated and reassociated); 10, 15, 20, 30 & 40 krpm; 280 nm; GuHCl; sucrose gradient centrifugation and PAGE also used; Dept. of Biochemistry, Univ. of Texas Health Science Center, San Antonio, TX 78284-7760

**Birck, C., Vachette, P., Welch, M., Swaren, P., Samama, J.-P. Is the function of the cdc2 kinase subunit proteins tuned by their propensities to oligomerize? Conformational states in solution of the cdc2 kinase partners p13(suc1) and p9(cksphy). Biochemistry 35, 5577-5585 (1996)

Optima XL-A, sed. equil., sed. vel., M(r), f, S, v-bar; Physarum polycephalum and Schizosaccharomyces pombe cdc2 kinase subunit proteins; An-60 Ti, 35 krpm (s.e.), 65 krpm (s.v.), 278 nm, 20deg.C; mass spectrometry, SEC and X-ray scattering also used; (Samama) Groupe de Cristallographie Biologique du Laboratoire de Pharmacologie et de Toxicologie Fondamentales du CNRS, 205 route de Narbonne, 31077 Toulouse, France UPR 8221

**Black, S. D., Martin, S. T. Evidence for conformational dynamics and molecular aggregation in cytochrome P450 102 (BM-3). Biochemistry 33, 12056-12062 (1994)

Optima XL-A, sed. equil., M, degree of association; sed. vel., D, S; Bacillus megaterium cytochrome P450 102; An-60 Ti, 7400-90,700 g (av) (s.v.), 2817 & 5009 g (s.e.), 278 or 418 nm; SEC also used; Dept. of Biochem., Univ. of Texas Health Center at Tyler, Tyler, TX 75710-2003

**Bonnete, F., Ebel, C., Zaccal, G., Elsenberg, H. Biophysical study of halophilic malate dehydrogenase in solution: revised subunit structure and solvent interactions of native and recombinant enzyme. J. Chem. Soc. Faraday Trans. 89, 2659-2666 (1995)

Optima XL-A, sed. equil., m; sed. vel., D, S; native and denatured recombinant malate dehydrogenase; 8, 15 & 30 krpm, 20deg.C, effect of salt concentration; light scattering and densimetry also used; (Zaccal) Inst. de Biologie Structurale, 41 avenue des Martyrs, F-38087 Grenoble Cedex 1, France

**Cann, J. R., Coombs, R. O., Howlett, G. J., Jacobsen, M. P., Winzor, D. J. Effects of molecular crowding on protein self-association: a potential source of error in sedimentation coefficients obtained by zonal ultracentrifugation in a sucrose gradient. Biochemistry 33, 10185-10190 (1994)

Optima XL-A, sed. vel., S; results compared with simulated run in SW 60 Ti with a sucrose gradient; yeast enolase used as a model dimerizing system; 60 krpm; effect of sucrose on polymerization equilibrium; (Winzor) Dept. of Biochemistry, Univ. of Queensland, Brisbane, QLD4072, Australia

**Chen, L. H., Kenyon, G. L., Curtin, F., Harayama, S., Bembenek, M. E., Hajipour, G., Whitman, C. P. 4-Oxalocrotonate tautomerase, an enzyme composed of 62 amino acid residues per monomer. J. Biol. Chem. 267, 17716-17721 (1992)

Optima XL-A, sed. equil., M; sed. vel., D, S; recombinant 4-oxalocrotonate tautomerase; An-60 Ti, 3 krpm (s.v.), 60 krpm (s.e.); monitored at 226, 236, 240 & 245 nm due to lack of aromatic side chains; interfaced to HP PC

**C^lfen, H., Harding, S. E., Wilson, E. K., Packman, L. C., Scrutton, N. S. Homodimeric and expanded behaviour of trimethylamine dehydrogenase in solution at different temperatures. Eur. Biophys. J. 24, 159-164 (1996)

Optima XL-A, sed. equil., m; sed. vel., g(s*), S; Methylophilus methylotrophus trimethylamine dehydrogenase homodimers; 10, 20 and 30 krpm (s.e.), 25-50 krpm (s.v.); 240, 280 and 443 nm; effect of temperature; 4, 15, 20 and 30deg.C; (Harding) National Centre for Macromolecular Hydrodynamics, Univ. of Nottingham, Sutton Bonington, LE12 5RD, UK

**Consalvi, V., Chiaraluce, R., Millevoi, S., Pasquo, A., Vecchini, P., Chiancone, E., Scandurra, R. Refolding pathway and association intermediates of glutamate dehydrogenase from the hyperthermophile Pyrococcus furiosus. Eur. J. Biochem. 239, 679-685 (1996)

Optima XL-A, sed. vel., S; Pyrococcus furiosus glutamate dehydrogenase and oligomers; 30 or 40 krpm, 280 nm, 20deg.C; CD, fluorescence, light scattering and SEC also used; Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli', Universita 'La Sapienza', Piazzale Aldo Moro, 5, I-00185 Roma, Italy

**Correia, J. J., Gilbert, S. P., Moyer, M. L., Johnson, K. A. Sedimentation studies on the kinesin motor domain constructs K401, K366, and K341. Biochemistry 34, 4898-4907 (1995)

Optima XL-A, sed. equil., M; sed. vel., S; recombinant Drosophila kinesin motor domain constructs K401, K366 and K341; An-60 Ti, 16-24 krpm (s.e.), 42 krpm (s.v.), 230-238 or 280 nm, 25deg.C; an ATPase; (Correia) Dept. of Biochemistry, Univ. of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216

**Dabora, J. M., Marqusee, S. Equilibrium unfolding of Escherichia coli ribonuclease H: characterization of a partially folded state. Protein Sci. 3, 1401-1408 (1994)

Optima XL-A, sed. equil., m; sed. vel., S; recombinant ribonuclease H monomer; 60 krpm (s.v.), 20 krpm (s.e.), effect of pH, GuHCl; Dept. of Mol. and Cell Biol., Div. of Biochem. and Mol. Biol., Univ. of California-Berkeley, Berkeley, CA 94720

**Dallmann, H. G., McHenry, C. S. DnaX complex of Escherichia coli DNA polymerase III holoenzyme. Physical characterization of the DnaX subunits and complexes. J. Biol. Chem. 270, 29563-29569 (1995)

Optima XL-A, sed. equil., M; sed. vel., D, S; f/f(min), Stokes' radius; bacterial DNA polymerase DnaX subunits tau and gamma; An-60 Ti, 15 krpm (s.e.), 30 krpm (s. v.), 280 nm, 4deg.C; BIAcore, gel filtration and PAGE also used; (McHenry) Dept. of Biochemistry, Biophysics and Genetics and Graduate Program in Molecular Biology, Univ. of Colorado Health Sciences Center, Denver, CO 80262

**Darke, P. L., Cole, J. L., Waxman, L., Hall, D. L., Sardana, M. K., Kuo, L. C. Active human cytomegalovirus protease is a dimer. J. Biol. Chem. 271, 7445-7449 (1996)

Optima XL-A, sed. vel., D, M, S; human cytomegalovirus monomer-dimer; 45 krpm, 280 nm, 20deg.C; also in presence of glycerol; SEC also used; Dept. of Antiviral Research, Merck Research Laboratories, West Point, Pennsylvania 19486

**Dickson, P. W., Jennings, I. G., Cotton, R. G. H. Delineation of the catalytic core of phenylalanine hydroxylase and identification of glutamate 286 as a critical residue for pterin function. J. Biol. Chem. 269, 20369-20375 (1994)

Optima XL-A, sed. equil., m, rat phenylalanine hydroxylase fragments concentration-dependent self-association; 10 krpm, 50 & 300 (g/ml; (Dickson) Russell Grimwade School of Biochemistry, Univ. of Melbourne, Parkville, Victoria 3052, Australia

**Djaballah, H., Rowe, A. J., Harding, S. E., Rivett, A. J. The multicatalytic proteinase complex (proteasome): structure and conformational changes associated with changes in proteolytic activity. Biochem. J. 292, 857-862 (1993)

Optima XL-A, sed. vel., effect of metal ion concentration (MnCl(2)) on S; MSE Centriscan, sed. vel., effect of substrate, SDS, KCl and denaturants on S; rat liver multicatalytic proteinase complex; (Rivett) Dept. of Applied Biochemistry and Food Science, Univ. of Nottingham, Sutton Bonington LE12 5RD, U.K.

**Dong, F., Gogol, E. P., von Hippel, P. H. The phage T4-coded DNA replication helicase (gp41) forms a hexamer upon activation by nucleoside triphosphate. J. Biol. Chem. 270, 7462-7473 (1995)

Optima XL-A, sed. vel., S; bacteriophage T4 helicase and its GTP-gamma-S or NTP complexes; An-D or An-F, 50 krpm, 280 nm, SEC & electron microscopy also; state of association; (von Hippel) Institute of Molecular Biology and Dept. of Chemistry, Univ. of Oregon, Eugene, OR 97403-1229

**Green, S. M., Gittis, A. G., Meeker, A. K., Lattman, E. E. One-step evolution of a dimer from a monomeric protein. Nature, Struct. Biol. 2, 746-751 (1995)

Optima XL-A, sed. equil., state of association; recombinant mutant Staphylococcal nuclease dimer; 22, 25 and 28 krpm, 280 nm, 25deg.C; X-ray diffraction also used; XL-A work performed by Preston Hensley; (Lattman) Dept. of Biophysics and Biophysical Chemistry, The Johns Hopkins Univ. School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205

**Gross, M., Lustig, A., Wallimann, T., Furter, R. Multiple-state equilibrium unfolding of guanidino kinases. Biochemistry 34, 10350-10357 (1995)

Optima XL-A, sed. equil., M(r); sed. vel., S; recombinant chicken sarcomere mitochondrial creatine kinase monomer; no speed, 20deg.C; GuHCl; CD, fluorescence and size exclusion chromatography also used; MRC Unit for Protein Function and Design, Cambridge Univ. Chemical Dept., Lensfield Rd., Cambridge CB2 1EW, U.K.

**Grossman, J. G., Abraham, Z. H. L., Adman, E. T., Neu, M., Eady, R. R., Smith, B. E., Hasnain, S. S. X-ray scattering using synchrotron radiation shows nitrite reductase from Achromobacter xylosoxidans to be a trimer in solution. Biochemistry 32, 7360-7366 (1993)

Optima XL-A, sed. equil., M(r); bacterial nitrate reductase; 14 krpm, 20deg.C, 227 nm; trimer; (Hasnain) Molecular Biophysics Group, SERC Daresbury Laboratory, Warrington WA4 4AD, Cheshire, U.K.

**Guijarro, J. I., Jackson, M., Chaffotte, A. F., Delepierre, M., Mantsch, H. H., Goldberg, M. E. Protein folding intermediates with rapidly exchangeable amide protons contain authentic hydrogen-bonded secondary structures. Biochemistry 34, 2998-3008 (1995)

Optima XL-A, sed. equil., m, state of association; E. coli tryptophan synthetase proteolytic domain F2; 20 krpm, then 40 krpm, 286 nm, 20deg.C, FC43 layer; CD, NMR & FTIR also; 101-residue polypeptide; (Goldberg) Unite de Biochimie Cellulaire, Institut Pasteur, 28 reu du Dr. Roux, 75724 Paris Cedex 15, France

**Hall, D. R., Jacobsen, M. P., Winzor, D. J. Stabilizing effect of sucrose against irreversible denaturation of rabbit muscle lactate dehydrogenase. Biophys. Chem. 57, 47-54 (1995)

Optima XL-A, sed. equil., M; rabbit muscle lactate dehydrogenase dimer; 12 krpm, 280 nm, 20deg.C; effect of sucrose on molecular crowding; (Winzor) Centre for Protein Structure, Function and Engineering, Dept. of Biochemistry, Univ. of Queensland, Brisbane, QLD 4072, Australia

**Hester, K., Luo, J., Burns, G., Braswell, E. H., Sokatch, J. R. Purification of active E1alpha(2)beta(2) of Pseudomonas putida branched-chain-oxoacid dehydrogenase. Eur. J. Biochem. 233, 828-836 (1995)

Optima XL-A, sed. equil., m; sed. vel., S, Stokes' radius; recombinant branched-chain-oxoacid dehydrogenase E1 component; 15 and 21 krpm (s.e.), 40 krpm (s.v.), 4deg.C, 277 or 279 nm; gel filtration also used; (Sokatch) Dept. of Biochemistry and Molecular Biology, Univ. of Oklahoma Health Sciences Center, P.O. Box 26901, Oklahoma City, OK 73190

**Howitt, S. M., Rodgers, A. J. W., Jeffrey, P. D., Cox, G. B. A mutation in which alanine 128 is replaced by aspartic acid abolishes dimerization of the b-subunit of the F(0)F(1)-ATPase from Escherichia coli. J. Biol. Chem. 271, 7038-7042 (1996)

Optima XL-A, sed. equil., m; state of association; recombinant F(0)F(1)-ATPase b-subunit and mutant; 15 krpm, 230 or 360 nm; SEC also used; Div. of Biochemistry and Molecular Biology, John Curtin School of Medical Research, Australian Natl. Univ., GPO Box 334, Canberra City, ACT 2601 Australia

**Jenkins, T. M., Hickman, A. B., Dyda, F., Ghirlando, R., Davies, D. R., Craigie, R. Catalytic domain of human immunodeficiency virus type 1 integrase: identification of a soluble mutant by systematic replacement of hydrophobic residues. Proc. Natl. Acad. Sci. 92, 6057-6061 (1995)

Optima XL-A, sed. equil., M(b); state of aggregation; recombinant HIV-1 integrase catalytic domain; 15, 20 & 25 krpm; 250 or 293 nm, 4deg.C; (Craigie) Bldg. 5, Rm. 301, Laboratory of Molecular Biology, Natl. Inst. of Diabetes & Kidney Diseases, NIH, Bethesda, MD 20892

**Jenkins, T. M., Engelman, A., Ghirlando, R., Craigie, R. A soluble active mutant of HIV-1 integrase. Involvement of both the core and carboxyl-terminal domains in multimerization. J. Biol. Chem. 271, 7712-7718 (1996)

Optima XL-A, sed. equil., K(a), K(d); HIV-1 virus integrase mutant dimer-tetramer; 10-16 krpm, 280 or 296 nm, 20deg.C; effect of speed or concentration; gel filtration also used; (Craigie) Bldg. 5, Rm. 301, Laboratory of Molecular Biology, NIDDK, Natl. Inst. of Health, Bethesda, MD 20892

**Jin, H., Emanuele, J. J., Jr., Fairman, R., Robertson, J. G., Hail, M. E., Ho, H.-T., Falk, P. J., Villafranca, J. J. Structural studies of Escherichia coli UDP-N-acetylmuramate:L-alanine ligase. Biochemistry 35, 1423-1431 (1996)

Optima XL-A, sed. equil., K(d), M(app), state of oligomerization; recombinant UNAM:L-Ala ligase monomer-dimer; An-60 Ti, 12, 16 and 20 krpm, 235, 280 and 295 nm, 4deg. and 37deg.C; CD and gel filtration also used; effect of substrates, concentration, rotor speed and temperature; Division of Macromolecular Structure and Analytical Research and Development, Bristol-Myers Squibb Pharmaceutical Research Inst., Princeton, NJ 08543-4000

**Kang, K. R., Wolff, E. C., Park, M. H., Folk, J. E., Chung, S. II. Identification of YHR068w in Saccharomyces cerevisiae chromosome VIII as a gene for deoxyhypusine synthase. Expression and characterization of the enzyme. J. Biol. Chem. 270, 18408-18412 (1995)

Optima XL-A, sed. equil., delta G, K(a), m; recombinant yeast deoxyhypusine synthase monomer-tetramer; 20deg.C; mass spectrometry and size-exclusion chromatography also used; (Park) Bldg. 30, Rm. 211, NIDR, NIH, Bethesda, MD 20892-4330

**Karlsson, A., Mesnildrey, S., Xu, Y., Morera, S., Janin, J., Veron, M. Nucleoside diphosphate kinase. Investigation of the intersubunit contacts by site-directed mutagenesis and crystallography. J. Biol. Chem. 271, 19928-19934 (1996)

Optima XL-A, sed. equil., m, state of oligomerization; recombinant NDP kinase mutants; 23 krpm, 280 nm, 25deg.C; SEC and X-ray crystallography also used; (Veron) Unite de Regulation Enzymatique des Activites Cellulaires, Institut Pasteur, 25 rue du Dr. Roux, 75724, Paris Cedex 15, France

**Keiler, K. C., Silber, K. R., Downard, K. M., Papayannopoulos, I. A., Biemann, K., Sauer, R. T. C-terminal specific protein degradation: activity and substrate specificity of the Tsp protease. Protein Sci. 4, 1507-1515 (1995)

Optima XL-A, sed. equil., m; recombinant Escherichia coli Tsp H(6) protease variant; 13 and 15 krpm, effect of conc.; CD and mass spectrometry also used; (Sauer) Dept. of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139

**Kelly, M., Lappalainen, P., Talbo, G., Haltia, T., van der Oost, J., Saraste, M. Two cysteines, two histidines, and one methionine are ligands of a binuclear purple copper center. J. Biol. Chem. 268, 16781-16787 (1993)

Optima XL-A, sed. equil., M; recombinant (cytochrome oxidase) purple CyoA copper center; XL-A work done by Ariel Lustig but no details given (Univ. Basel Biocenter)

**Kendrew, S. G., Harding, S. E., Hopwood, D. A., Marsh, E. N. G. Identification of a flavin:NADH oxidoreductase involved in the biosynthesis of actinorhodin. Purification and characterization of the recombinant enzyme. J. Biol. Chem. 270, 17339-17343 (1995)

Optima XL-A, sed. equil., M(0), (r,w); MSE Centriscan 75, sed. vel., S; recombinant flavin:NADH oxidoreductase monomer-dimer; 280 nm, 20deg.C; gel filtration also used; effect of pH; (Marsh) Dept. of Biochemistry and Cambridge Centre for Molecular Recognition, Univ. of Cambridge, Tennis Court Rd., Cambridge CB2 1QW, United Kingdom

**Kilby, P. M., Primrose, W. U., Roberts, G. C. K. Changes in the structure of bovine phospholipase A(2) upon micelle binding. Biochem. J. 305, 935-944 (1995)

Optima XL-A, sed. equil., m of protein component; beef pancreatic phospholipase A(2)-SDS complexes; 18 or 40 krpm, 280 nm, 20deg.C; effect of D(2)O; Dept. of Biochemistry and Biological NMR Centre, Univ. of Leicester, Adrian Duilding, University Road, Leicester, LE1 7RH, UK

**Kortt, A. A., Caldwell, J. B., Lilley, G. G., Edwards, R., Vaughan, J., Stewart, D. J. Characterization of a basic serine proteinase (pl ~ 9.5) secreted by virulent strains of Dichelobacter nodosus and identification of a distinct, but closely related, proteinase secreted by benign strains. Biochem. J. 299, 521-525 (1994)

Optima XL-A, sed. equil, m; bacterial basic serine proteinase; gel filtration (gave anomalous results) & PAGE also used; (Kortt) Commonwealth Scientific and Industrial Research Organisation, Division of Biomolecular Engineering, 343 Royal Parade, Parvill, Victoria 3052, Australia

**Lamhasni, S., Larsen, A. K., Barray, M., Monnot, M., Delain, E., Fermandjian, S. Changes of self-association, secondary structure, and biological activity properties of topoisomerase II under varying salt conditions. Biochemistry 34, 3632-3639 (1995)

Optima XL-A, sed. equil., K(a), M; sed. vel., S; S. cerevisiae DNA topoisomerase II; 7000 or 8500 rpm (s.e.); 60 krpm (s.v.); 280 nm; effect of protein and salt concentration on state of association; CD and PAGE also; Departement de Biologie Structurale and Unite de Physicochimie at Pharmacologie des macromolecules Biologiques, CNRS URA 147, INSERM U 140, Institut Gustave Roussy, Villejuif 94805, Cedex, France

**Lebowitz, J. Stability of the human immunodeficiency virus-1 reverse transcriptase heterodimer. Application Information A-1807A. Fullerton, Calif., Beckman Instruments, Inc., 1995.

Optima XL-A, band sedimentation velocity in D(2)O; recombinant HIV-1 reverse transcriptase heterodimer; no exptl. detail given (most work was done in Model E with Scanner); Univ. of Alabama, Birmingham, AL

**Lebowitz, J., Kar, S., Braswell, E., McPherson, S., Richard, D. L. Human immunodeficiency virus-1 reverse transcriptase heterodimer stability. Protein Sci. 3, 1374-1382 (1994)

Optima XL-A, sed. equil., K, M; HIV-1 reverse transcriptase heterodimer; 12-16 krpm; effect of temperature (5, 20 & 37deg.C); (Lebowitz), Dept. of Microbiology, 520 CHSB, Univ. of Alabama at Birmingham, Birmingham, AL 35294

**Lin, K., Hwang, P. K., Fletterick, R. J. Mechanism of regulation in yeast glycogen phosphorylase. J. Biol. Chem. 270, 26833-26839 (1995)

Optima XL-A, sed. equil., m, state of oligomerization; recombinant native and mutant glycogen phosphorylases and their activator or inhibitor complexes; 5000 rpm, 280 nm, 25deg.C; PAGE also used; (Fletterick) Dept. of Biochemistry and Biophysics, Univ. of California, San Francisco, CA 94143-0448

**Marchand, P., Tang, J., Bond, J. S. Membrane association and oligomeric organization of the alpha and beta subunits of mouse meprin A. J. Biol. Chem. 269, 15388-15393 (1994)

Optima XL-A, sed. equil., M,v-bar; mouse kidney native and oxidized meprin A (metalloproteinase) dimer & tetramer; 5 or 8 krpm; SDS-PAGE also; 220 & 280 nm; Dept. of Biochemistry and Molecular Biology, Pennsylvania State Univ. College of Medicine, Hershey, PA 17033

**McCance, S. G., Castellino, F. J. Contributions of individual kringle domains toward maintenance of the chloride-induced tight conformation of human glutamic acid-1 plasminogen. Biochemistry 34, 9581-9586 (1995)

Optima XL-A, sed. vel., S; human Glu(1)-plasminogen mutants; 60 krpm, 280 nm, 20deg.C; effect of Cl(-) ion and epsilon-aminocaproic acid; PAGE also used; (Castellino) Dept. of Chemistry and Biochemistry, Univ. of Notre Dame, Notre Dame, IN 46556

**Mouz, N., Tricot, C., Ebel, C., Petillot, Y., Stalon, V., Dideberg, O. Use of a designed fusion protein dissociates allosteric properties from the dodecameric state of Pseudomonas aeruginosa catabolic ornithine carbamoyltransferase. Proc. Natl. Acad. Sci. 93, 9414-9419 (1996)

Optima XL-A, sed. equil., m; sed. vel., S; recombinant bacterial ornithine carbamoyltransferase; An-60 Ti, 10 krpm (s.e.), 30 krpm (s.v.), 10deg.C; gel filtration and PAGE also used; (Dideberg) Laboratoire de Cristallographie Macromoleculaire, Institut de Biologie Structurale Jean-Pierre EBEL, Commissariat a l'Energie Atomique-Centre National de la Recherche Scientifique, 41 avenue des Martyrs, F-38027 Grenoble Cedex 1, France

**Musatov, A., Robinson, N. C. Detergent-solubilized monomeric and dimeric cytochrome bc (1) isolated from bovine heart. Biochemistry 33, 13005-13012 (1994)

Optima XL-A, sed. equil., m; sed. vel., S; beef heart mitochondrial bc (1) monomers and dimers; 6 or 22 krpm; 416 nm; effect of detergents and salts; (Robinson) Dept. of Biochemistry, Univ. of Texas Health Science Center, 7703 Floyd Curl Dr., San Antonio, TX 78284-7760

**Olson, M. W., Dallmann, H. G., McHenry, C. S. DnaX complex of Escherichia coli DNA polymerase III holoenzyme. The chi-psi complex functions by increasing the affinity of tau and gamma for delta*delta( to a physiologically relevant range. J. Biol. Chem. 270, 29570-29577 (1995)

Optima XL-A, sed. equil., M; sed. vel., D, S, Stokes' radius; bacterial DNA polymerase III chi-psi heterodimer complex; An-60 Ti, 15-35 krpm (s.e.), 40 krpm (s.v.), 230 and 280 nm, 4deg.C; BIAcore also used; (McHenry) Dept. of Biochemistry, Biophysics and Genetics and Graduate Program in Molecular Biology, Univ. of Colorado Health Sciences Center, Denver, CO 80262

**Nenortas, E., Beckett, D. Purification and characterization of intact and truncated forms of the Escherichia coli biotin carboxyl carrier subunit of acetyl-CoA carboxylase. J. Biol. Chem. 271, 7559-7567 (1996)

Optima XL-A, sed. equil., M(r); Escherichia coli acetyl-CoA carboxylase biotin carboxyl carrier subunit and aggregates; An-55, 16, 22 and 28 krpm, 20deg.C; fluorescence and mass spectrometry also used; (Beckett) Dept. of Chemistry and Biochemistry, Univ. of Maryland, Baltimore County, Baltimore, MD 21228

**Pecorari, F., Minard, P., Desmadril, M., Yon, J. M. Occurrence of transient multimeric species during the refolding of a monomeric protein. J. Biol. Chem. 271, 5270-5276 (1996)

Optima XL-A, sed. equil., m, state of oligomerization; recombinant yeast phosphoglycerate kinase fragments; 25 krpm, 276 nm, 20deg.C; light scattering also used; (Desmadril) Laboratoire d'Enzymologie Physicochimique et Moleculaire Unite de Recherches du CNRS, Universite de Paris-Sud, Bat 430, 91405 Orsay, Cedex France

**Powers, V. M., Yang, Y. R., Fogli, M. J., Schachman, H. K. Reconstitution of active catalytic trimer of aspartate transcarbamoylase from proteolytically cleaved polypeptide chains. Protein Sci. 2, 1001-1012 (1993)

Optima XL-A, sed. vel., S; Model E, schlieren optics, diff. sed. vel., delta s/s with and without PALA ligand; E. coli ATCase holoenzyme, trimers and cleaved, and reconstituted enzyme; 60 krpm; Dept. of Molecular and Cell Biology and Virus Laboratory, Wendell M. Stanley Hall, Univ. of California, Berkeley, CA 94720

**Rault-Leonardon, M., Atkinson, M. A. L., Slaughter, C. A., Moomaw, C. R., Srere, P. A. Azotobacter vinelandii citrate synthase. Biochemistry 34, 257-263 (1995)

Optima XL-A, m, S; gel filtration and PAGE also used; 6 & 7 krpm (s.e.), 25, 35 & 40 krpm (s.v.), 280 nm; gel filtration & PAGE also; (Srere) Dept. of Veterans Affairs Medical Center, 4500 S. Lancaster Rd., Dallas TX 75216

**Robertson, J. G. Determination of subunit dissociation constants in native and inactivated CTP synthetase by sedimentation equilibrium. Biochemistry 34, 7533-7541 (1995)

Optima XL-A, sed. equil., K(d), M(r); native and modified Escherichia coli CTP synthetase monomer-dimer-tetramer; An-60 Ti, 8, 12, 16 & 20 krpm, 4deg.C, 230 or 280 nm; (Robertson) Enzymology Laboratory, Div. of Macromolecular Structure, Bristol-Myers Squibb Pharmaceutical Inst., Princeton, NJ 08543-4000

**Robertson, J. G., Yanchunas, J., Villafranca, J. J. Dimerization of native and C-terminally proteolyzed p56(lck) tyrosine kinase. Arch. Biochem. Biophys. 317, 259-266 (1995)

Optima XL-A, sed. equil., K(d), M(r), state of association; native and proteolyzed recombinant tyrosine kinase monomer-dimer; An-60 Ti, 12, 18 & 25 krpm, 280 nm; effect of speed; (Robertson) Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, NJ 08543-4000

**Sackett, D. L., Kosk-Kosicka, D. The active species of plasma membrane Ca(2+)-ATPase are a dimer and a monomer-calmodulin complex. J. Biol. Chem. 271, 9987-9991 (1996)

Optima XL-A and Model E with Scanner, sed. equil., m, state of oligomerization; erythrocyte membrane Ca(2+)-ATPase dimer and monomer-calmodulin complex; An-60 Ti, 12-15 krpm; 230, 280 and 350 nm, 20 or 25deg.C; (Kosk-Kosicka) Dept. of Anesthesiology/Critical Care Medicine, The Johns Hopkins Univ. School of Medicine, Baltimore, MD 21287

**Serina, L., Blondin, C., Krin, E., Sismeiro, O., Danchin, A., Sakamoto, H., Gilles, A.-M., Barzu, O. Escherichia coli UMP-kinase, a member of the aspartokinase family, is a hexamer regulated by guanine nucleotides and UTP. Biochemistry 34, 5066-5074 (1995)

Optima XL-A, sed. equil., m; recombinant UMP-kinase hexamer; 6 & 9 krpm, 280 nm, 20 ; fluorescence & PAGE also used; (Danchin) Unite de Biochimie des Regulations Cellulaires, Institut Pasteur, 28 rue du Docteur Roux 75724 Paris Cedex 15, France

**Serina, L., Bucurenci, N., Gilles, A.-M., Surewicz, W. K., Fabian, H., Mantsch, H. H., Takahashi, M., Petrescu, I., Batelier, G., Barzu, O. Structural properties of UMP-kinase from Escherichia coli: modulation of protein solubility by pH and UTP. Biochemistry 35, 7003-7011 (1996)

Optima XL-A, sed. equil., m, state of oligomerization; sed. vel., S; bacterial UMP-kinase; An-60 Ti, 6, 10 and 20 krpm (s.e.), 50 krpm (s.v.), 280 nm, 20deg.C; effect of pH 6 and 9 and GuHCl; fluorescence, CD, IR spectroscopy, and gel permeation chromatography also used; (Barzu) Unite de Biochimie des Regulations Cellulaires, Institut Pasteur, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France

**Sheta, E., Schwarz, P., McMillan, K., Hansen, J. C., Masters, B. S. S. Analytical ultracentrifugation studies reveal a monomer-dimer equilibrium in solutions of cerebellar nitric xide synthase. FASEB J. 8, A1383 (1994)

Optima XL-A, sed. equil., m; sed. vel., S; rat brain nitric oxide synthase monomer-dimer; Univ. of Texas Health Science Center, San Antonio, TX 78284-7760

**Sinclair, J. F., Ziegler, M. M., Baldwin, T. O. Kinetic partitioning during protein folding yields multiple native states. Nature Struct. Biol. 1, 320-326 (1994)

Optima XL-A, sed. equil., M; recombinant luciferase beta-subunit; 16 krpm, 280 nm, 23deg.C; Center for Macromolecular Design and the Dept. of Biochemistry and Biophysics, Texas A & M Univ., College Station, TX 77843-2128

**Staunton, J., Caffrey, P., Aparicio, J. F., Roberts, G. A., Bethell, S. S., Leadlay, P. F. Evidence for a double-helical structure for modular polyketide synthases. Nature, Struct. Biol. 3, 188-192 (1996)

Optima XL-A, sed. equil., M(r), state of oligomerization; Saccharopolyspora erythraea 6-deoxyerythronolide B synthase; An-60 Ti, 3, 5 and 7 krpm, 219 and 280 nm; effect of concentration and rotor speed; (Leadlay) Dept. of Biochemistry, Univ. of Cambridge, Tennis Court Rd., Cambridge CB2 1QW, UK

**Truckses, D. M., Somoza, J. R., Prehoda, K. E., Miller, S. C., Markley, J. L. Coupling between trans/cis proline isomerization and protein stability in staphylococcal nuclease. Protein Sci. 5, 1907-1916 (1996)

Optima XL-A, sed. equil., state of association; recombinant bacterial mutant nucleases; 25, 33 and 37 krpm; 280 nm; NMR and X-ray crystallography also used; (Markley) Dept. of Biochemistry, College of Agricultural and Life Sciences, Univ. of Wisconsin-Madison, 420 Henry Mall, Madison, WI 53706

**Usobiaga, P., Medrano, F. J., Gasset, M., Garcia, J. L., Saiz, J. L., Rivas, G., Laynez, J., Menendez, M. Structural organization of the major autolysin from Streptococcus pneumoniae. J. Biol. Chem. 271, 6832-6838 (1996)

Optima XL-A, sed. equil., K, state of aggregation; sed. vel., S; bacterial LytA and c-LytA amidases; 15, 20 and 42 krpm (s.e.); 60 krpm (s.v.), 280 nm, 25deg.C; effect of choline concentration and prior heating of sample; differential scanning calorimetry also used; (Menendez) Instituto de Quimica-Fisica "Rocasolano," Consejo Superior de Investigaciones Cientificas (CSIC), Serrano 119, 28006 Madrid, Spain

**Voelker, P., McRorie, D. alpha-Chymotrypsin: characterization of a self-associating system in the analytical ultracentrifuge. Technical Information T-1782A. Fullerton, Calif., Beckman Instruments, Inc., 1994.

Optima XL-A, sed. equil., K; alpha-chymotrypsin self-association; effect of concentration; Beckman Instruments, Inc., 1050 Page Mill Rd., Palo Alto, CA 94304

**Ward, D. G., Cavieres, J. D. Solubilized alpha/beta Na, K-ATPase remains protomeric during turnover yet shows apparent negative cooperativity toward ATP. Proc. Natl. Acad. Sci. 90, 5332-5336 (1993)

Optima XL-A or MSE Centriscan 75, sed. vel., S; Na,K-ATPase; 40 krpm; 55 krpm for active enzyme sedimentation in Centriscan & band-forming cell with phenol red indicator, 550 nm; Dept. of Physiology, Leicester Univ., P.O. Box 138, Leicester LE1 9HN, U.K.

**Ward, D. G., Cavieres, J. D. Binding of 2'(3')-O-(2,4,6-trinitrophenyl)ADP to soluble alpha-beta promoters of Na,K-ATPase modified with fluorescein isothiocyanate. Evidence for two distinct nucleotide sites. J. Biol. Chem. 271, 12317-12321 (1996)

Optima XL-A, sed. vel., S; pig kidney native and FITC-treated Na,K-ATPases; 40 krpm, 20deg.C; (Sites) Dept. of Cell Physiology and Pharmacology, Leicester Univ., P.O. Box 138, Leicester LE1 9HN, UK

**Wolff, E. C., Lee, Y. B., Chung, S. I., Folk, J. E., Park, M. H. Deoxyhypusine synthase from rat testis: purification and characterization. J. Biol. Chem. 270, 8660-8666 (1995)

Optima XL-A, sed. equil., degree of association, m; rat testis deoxyhypusine synthase15 krpm, 230 nm, 20deg.C; m results compared in table with results from mass spectrometry, gel filtration and SDS-PAGE; Laboratory of Cellular Development and Oncology, National Institute of Dental Research, NIH, Bethesda, MD 20892-4330

**Yang, Y. R., Schachman, H. K. In vivo formation of active aspartate transcarbamoylase from complementing fragments of the catalytic polypeptide chains. Protein Sci. 2, 1013-1023 (1993)

Optima XL-A, sed. vel., S with and without PALA ligand; E. coli aspartate transcarbamoylase and catalytic subunit trimers; Dept. of Molecular and Cell Biology and Virus Laboratory, Wendell M. Stanley Hall, Univ. of California, Berkeley, CA 94720

**Xia, J., Sinclair, J. F., Baldwin, T. O., Lindahl, P. A. Carbon monoxide dehydrogenase from Clostridium thermoaceticum: quaternary structure, stoichiometry of its SDS-induced dissociation, and characterization of the faster-migrating form. Biochemistry 35, 1965-1971 (1996)

Optima XL-A, sed. equil., M(r); bacterial carbon monoxide dehydrogenase and dissociation products; 8-15 krpm, 4-20deg.C, 420 nm; effect of SDS; (Lindahl) Dept. of Chemistry, Texas A and M Univ., College Station, TX 77843

**Yang, Y. R., Schachman, H. K. A bifunctional fusion protein containing the maltose-binding polypeptide and the catalytic chain of aspartate transcarbamoylase: assembly, oligomers, and domains. Biophys. Chem. 59, 289-297 (1996)

Optima XL-A, sed. equil., m, sed. vel., g*(s), S; recombinant maltose-binding protein complex and cleavage products; 50 krpm (s.v.), 235 or 280 nm, 20deg.C; PAGE also used; (Schachman) Dept. of Molecular and Cell Biology, Wendell M. Stanley Hall, Univ. of California, Berkeley, CA 94720-3206

**Zolkiewski, M., Nosworthy, N. J., Ginsburg, A. Urea-induced dissociation and unfolding of dodecameric glutamine synthetase from Escherichia coli: calorimetric and spectral studies. Protein Sci. 4, 1544-1552 (1995)

Optima XL-A, sed. equil., m; sed. vel., S; bacterial glutamine synthetase subunits; various speeds, 276 or 280 nm, 20deg.C; various urea concentrations; CD, light scattering and isothermal reaction calorimetry also used; (Ginsburg) Natl. Inst. of Health, Bldg. 3, Rm. 208, Bethesda, MD 20802-0340

Proteins: Receptors

**Brown, P. M., Tagari, P., Rowan, K. R., Yu, V. L., O'Neill, G. P., Middaugh, C. R., Sanyal, G., Ford-Hutchinson, A. W., Nicholson, D. W. Epitope-labeled soluble human interleukin-5 (IL-5) receptors. Affinity cross-link labeling, IL-5 binding, and biological activity. J. Biol. Chem. 270, 29236-29243 (1995)

Optima XL-A, sed. equil., m; recombinant-soluble IL-5 receptor domain and its interleukin-5 complex; An-60 Ti, 16 and 22 krpm, 4deg.C; BIAcore, CD and fluorescence also used; (Nicholson) Dept. of Biochemistry and Molecular Biology, Merck Frosst Centre for Therapeutic Research, P.O. Box 1005, Pointe Claire-Dorval, Quebec H9R 4P8, Canada

**Cheng, L., Norris, A. W., Tate, B. F., Rosenberger, M., Grippo, J. F., Li, E. Characterization of the ligand binding domain of human retinoid X receptor alpha expressed in Escherichia coli. J. Biol. Chem. 269, 18662-18667 (1994)

Optima XL-A, sed. equil., M; recombinant apo- and holo-DEF human retinoid X receptor peptide and ligand complex; (Rosenberger) Oncology, Hoffmann-LaRoche, Nutley, NJ 07110

**Cochran, A. G., Kim, P. S. Imitation of Escherichia coli aspartate receptor signaling in engineered dimers of the cytoplasmic domain. Science 271, 1113-1116 (1996)

Optima XL-A, sed. equil., state of oligomerization; recombinant bacterial aspartate receptor fragments; 9, 11 and 14 krpm; effect of glycerol; Howard Hughes Medical Inst., Whitehead Inst. for Biomedical Research, Dept. of Biology, Massachusetts Inst. of Technology, Nine Cambridge Ctr., Cambridge, MA 02142

**Cosgrove, L., Lovrecz, G. O., Verkuylen, A., Cavaleri, L., Black, L. A., Bentley, J. D., Howlett, G. J., Gray, P. P., Ward, C. W., McKern, N. M. Purification and properties of insulin receptor ectodomain from large-scale mammalian cell culture. Protein Expression Purif. 6, 789-798 (1995)

Optima XL-A, sed. equil., M; sed. vel., S; recombinant human insulin receptor ectodomain; 5 krpm (s.e.), 235 and 280 nm, 20deg.C; gel filtration and PAGE also used; Division of Biomolecular Engineering, CSIRO, Parkville, Victoria 3052, Australia

**Horan, T., Wen, J., Narhi, L., Parker, V., Garcia, A., Arakawa, T., Philo, J. Dimerization of the extracellular domain of granulocyte-colony stimulating factor receptor by ligand binding: a monovalent ligand induces 2:2 complexes. Biochemistry 35, 4886-4896 (1996)

Optima XL-A, sed. equil., K, state of association; recombinant granulocyte-colony stimulating factor receptor and its ligand complex; 5800, 7000 and 8000 rpm; 230 or 280 nm; CD and light scattering/SEC also used; (Arakawa) Amgen Inc., Thousand Oaks, CA 91320-1789

**Johanson, K., Appelbaum, E., Doyle, M., Hensley, P., Zhao, B., Abdel-Meguid, S. S., Young, P., Cook, R., Carr, S., Matico, R., Cusimano, D., Dul, E., Angelichio, M., Brooks, I., Winborne, E., McDonnell, P., Morton, T., Bennett, D., Sokoloski, T., McNulty, D., Rosenberg, M., Chaiken, I. Binding interactions of human interleukin 5 with its receptor alpha subunit. Large scale production, structural, and functional studies of Drosophila-expressed recombinant proteins. J. Biol. Chem. 270, 9459-9471 (1995)

Optima XL-A, sed. equil., m, stoichiometry; a recombinant human interleukin 5, its receptor alpha subunit and complex; 25deg.C; PAGE, size exclusion chromatrography, mass spectrometry, and filtration microcalorimetry also used; (Chaiken) Dept. of Molecular Immunology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406

**Junghans, R. P., Stone, A. L., Lewis, M. S. Biophysical characterization of a recombinant soluble interleukin 2 receptor (Tac). Evidence for a monomeric structure. J. Biol. Chem. 271, 10453-10460 (1996)

Optima XL-A, sed. vel., S; Model E with Scanner, sed. equil., M, v-bar; recombinant human soluble interleukin 2 receptor (Tac); 20 krpm (s.e.), 280 nm; 54 krpm, 230 nm; 20deg.C; CD and gel filtration also used; effect of salt concentration; New England Deaconess Hospital, 99 Brookline Ave., Rm. 301, Boston, MA 02215

**Keown, M. B., Ghirlando, R., Young, R. J., Beavil, A. J., Owens, R. J., Perkins, S. J., Sutton, B. J., Gould, H. J. Hydrodynamic studies of a complex between the Fc fragment of human IgE and a soluble fragment of the Fc-epsilon-RI alpha chain. Proc. Natl. Acad. Sci. 92, 1841-1845 (1995)

Optima XL-A, sed. equil., M(b); sed. vel., S; recombinant human IgE, its Fc-epsilon-RI receptor fragment, and complex; 11-17 krpm & 18-22 krpm (s.e.); 40 & 50 krpm (s.v.); 280 nm; PAGE also used; (Gould) The Randall Institute, King's College London, 26-29 Drury Lane, London WC2B 5RL, UK

**Malchiodi, E. L., Eisenstein, E., Fields, B. A., Ohlendorf, D. H., Schlievert, P. M., Karjalainen, K., Mariuzza, R. A. Superantigen binding to a T cell receptor beta chain of known three-dimensional structure. J. Exp. Med. 182, 1833-1845 (1995)

Optima XL-A, sed. equil., K(d), M; recombinant T-cell receptor beta-chain, bacterial toxin superantigens, and their complexes; An 55, 22-30 krpm, 20-25deg.C; BIAcore also used and K(d)s compared with XL-A data; (Mariuzza) Center for Advanced Research in Biotechnology, 9600 Gudelsky Dr., Rockville, MD 20850

**Pennica, D., Kohr, W. J., Fendly, B. M., Shire, S. J., Raab, H. E., Borchardt, P. E., Lewis, M., Goeddel, D. V. Characterization of a recombinant extracellular domain of the type 1 tumor necrosis factor receptor: evidence for tumor necrosis factor-alpha induced receptor aggregation. Biochemistry 31, 1134-1141 (1992)

Optima XL-A, sed. equil., M; recombinant tumor necrosis factor receptor aggregation; An-60 Ti, 15 or 18 krpm, 18-24 h; (Pennica) Dept. of Molecular Biology, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080.

**Pennica, D., Lam, V. T., Weber, R. F., Kohr, W. J., Basa, L. J., Spellman, M. W., Ashkenazi, A., Shire, S. J., Goeddel, D. V. Biochemical characterization of the extracellular domain of the 75-kilodalton tumor necrosis factor receptor. Biochemistry 32, 3131-3138 (1993)

Optima XL-A, sed. equil., M(r); recombinant human tissue factor-alpha, -beta, receptor, and complexes; 15 krpm, 235 nm; Depts. of Molecular Biology, Protein Chemistry, Medicinal and Analytical Chemistry, Pulmonary Research, and Pharmaceutical Research and Development, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Philo, J. S., Aoki, K. H., Arakawa, T., Narhi, L. O., Wen, J. Dimerization of the extracellular domain of the erythropoietin (EPO) receptor by EPO: one high-affinity and one low-affinity interaction. Biochemistry 35, 1681-1691 (1996)

Optima XL-A, sed. equil., K(d), M(r); recombinant glycosylated and deglycosylated erythropoietin receptor-erythropoietin interaction; 10, 11, 15 and 18 krpm (also final run at 48 krpm to establish baseline); 230 and 280 nm; light scattering/size exclusion chromatography and titration calorimetry also used; Protein Chemistry Dept., Amgen, Inc., Amgen Ctr., Thousand Oaks, CA 91320

**Shire, S. J. Analytical ultracentrifugation and its use in biotechnology. Modern Analytical Ultracentrifugation, pp. 261-297. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A, sed. equil., M; recombinant HIV-1 envelope glycoprotein, recombinant apolipoprotein A, and human tumor necrosis factor type 1 receptor and its TNF-alpha complex; 5, 10 or 15 krpm; Dept. of Pharmaceutical R&D, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Ward, L. D., Howlett, G. J., Discolo, G., Yasukawa, K., Hammacher, A., Moritz, R. L., Simpson, R. J. High affinity interleukin-6 receptor is a hexameric complex consisting of two molecules each of interleukin-6, interleukin-6 receptor, and gp-130. J. Biol. Chem. 269, 23286-23289 (1994)

Optima XL-A, sed. equil., M; recombinant human interleukin-6, its receptor and IL-6-receptor-gp-130 complex; 12-, 10-, 8- and 6-krpm; BIAcore & SEC also used; (Simpson) Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research, Post Office Royal Melbourne Hospital, Parksville, Victoria 3050, Australia

**Ward, L. D., Howlett, G. J., Hammacher, A., Weinstock, J., Yasukawa, K., Simpson, R. J., Winzor, D. J. Use of a biosensor with surface plasmon resonance detection for the determination of binding constants: measurement of interleukin-6 binding to the soluble interleukin-6 receptor. Biochemistry 34, 2901-2907 (1995)

Optima XL-A, sed. equil., M; recombinant interleukin and its receptor; 8 & 12 krpm 20deg.C, 230 nm; BIAcore used for binding constants; (Simpson) Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research, P.O., Royal Melbourne Hospital, Parkville, Victoria 3050, Australia

Proteins: Other Proteins

**Aerts, T., Wang, Q. H., Tatarkova, S., Clauwaert, J. Physical-chemical characterization of the different individual cortical alpha-crystallin fractions from bovine lenses. Progress in Colloid & Polymer Science, Vol. 99, pp. 94-100. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A, sed. equil., M(w); sed. vel., g(s); f/f(0); calf lens alpha-crystallin fractions; 280 nm, 20deg.C; (Clauwaert) Biophysics Research Group, Dept. of Biochemistry, Univ. of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium

**Babitzke, P., Stults, J. T., Shire, S. J., Yanofsky, C. TRAP, the trp RNA-binding attenuation protein of Bacillus subtilis, is a multisubunit complex that appears to recognize G/UAG repeats in the trpEDCFBA and trpG transcripts. J. Biol. Chem. 269, 16597-16604 (1994)

Optima XL-A, sed. equil., m; bacterial trp RNA-binding attenuation protein subunit composition; 8000 rpm and 25 krpm, effect of conc.; MALDI M/S and SDS-PAGE also used; (Yanofsky) Dept. of Biological Sciences, Stanford Univ., Stanford, CA 94305

**Bain, D. L., Ackers, G. K. Self-association and DNA binding of lambda cI repressor N-terminal domains reveal linkage between sequence-specific binding and the C-terminal cooperativity domain. Biochemistry 33, 14679-14689 (1994)

Optima XL-A, sed. equil., delta G, M(r); Model E, interference optics, extinction coefficient; recombinant bacteriophage lambda cI repressor N-terminal domains self-association; 10-20 krpm; effect of conc., temperature & KCl on monomer-dimer-tetramer stoichiometry; 280-290 nm; Dept. Biochem. and Mol. Biophysics, Washington Univ. School of Medicine, St. Louis, MO 63110

** Benaroudj, N., Batelier, G., Triniolles, F., Ladjimi, M. M. Self-association of the molecular chaperone HSC70. Biochemistry 34, 15282-15290 (1995)

Optima XL-A, sed. equil., K(a), M(w); sed. vel., S; recombinant heat shock cognate protein HSC70 monomer, dimer and trimer; An-60 Ti, 8, 12 and 16 krpm (s.e.), 60 krpm (s.v.), 280 nm, 20deg.C; PAGE and SEC also used; (Ladjimi) Laboratoire d'Enzymologie, CNRS, 91198 Gif-sur-Yvette, Cedex, France

**Benaroudj, N., Triniolles, F., Ladjimi, M. M. Effect of nucleotides, peptides, and unfolded proteins on the self-association of the molecular chaperone HSC70. J. Biol. Chem. 271, 18471-18476 (1996)

Optima XL-A, sed. equil., M(w), state of association; sed. vel., S; chaperone HSC 70 mononer-oligomer; An-60 Ti, 11 krpm, 4deg.C, (s.e.); 20deg.C (s.v.); SEC also used; effect of nucleotide and cations; (Ladjimi) Laboratoire d'Enzymologie et de Biochimie Structurales CNRS, 91198 Gif-sur-Yvette Cedex, France

**Bender, R. C., Bayne, C. J. Purification and characterization of a tetrameric alpha-macroglobulin proteinase inhibitor from the gastropod mollusc Biomphalaria glabrata. Biochem. J. 316, 893-900 (1996)

Optima XL-A, sed. equil., m; snail alpha-macroglobulin proteinase inhibitor; 4000 rpm, 280 nm, 4deg.C, MALDI-mass spectrometry and PAGE also used; Dept. of Zoology, Cordley Hall 3029, Oregon State Univ., Corvallis, OR 97331-2914

**Boice, J. A., Fairman, R. Structural characterization of the tumor suppressor p16, an ankyrin-like repeat protein. Protein Sci. 5, 1776-1784 (1996)

Optima XL-A, sed. equil., M(r), state of association; recombinant human tumor suppressor p16 monomer-dimer; An-60 Ti, 15, 20, 25 and 35 krpm; 239 and 280 nm, 4deg.C; CD and fluorescence also used; effect of concentration; (Fairman) Div. of Macromolecular Structure, Bristol-Myers Squibb Pharmaceutical Research Inst., P. O. Box 4000, Princeton, NJ 08543-4000

**Brooks, I., Wetzel, R., Chan, W., Lee, G., Watts, D. G., Soneson, K. K., Hensley, P. Association of REI immunoglobulin light chain V(L) domains: the functional linearity of parameters in equilibrium analytical ultracentrifuge models for self-associating systems. Modern Analytical Ultracentrifugation, pp. 15-36. Edited by T. M. Schuster and T. M. Laue. Boston,

Birkhauser, 1994.

Optima XL-A, sed. equil., state of association; wt REI immunoglobin light chain monomer-dimer; 25 krpm; see Fig. 5; Dept. of Macromolecular Sciences, Smithkline Beecham Pharmaceuticals, King of Prussia, PA 19406-0939

**Bubb, M. R., Spector, I., Bershadsky, A. D., Korn, E. D. Swinholide A is a microfilament disrupting marine toxin that stabilizes actin dimers and severs actin filaments. J. Biol. Chem. 270, 3463-3466 (1995)

Optima XL-A, sed. vel., S; effect of swinholide A on actin state of association; 53 krpm, 290 nm, 18deg.C; (Korn) Bldg. 3, Rm. B1-22, NIH, Bethesda, MD 20892

**Burrows, S. D., Doyle, M. L., Murphy, K. P., Franklin, S. G., White, J. R., Brooks, I., McNulty, D. E., Scott, M. O., Knutson, J. R., Porter, D., Young, P. R., Hensley, P. Determination of the monomer-dimer equilibrium of interleukin-8 reveals it is a monomer at physiological concentrations. Biochemistry 33, 12741-12745 (1994)

Optima XL-A, sed. equil., degree of association; recombinant human interleukin-8 monomer-dimer equilibrium; 45 krpm; fluorescence anisotropy & titration microcalorimetry also; (Young) Dept. Mol. Immunol., SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406

**Cabral, J. H. M., Petosa, C., Sutcliffe, M. J., Raza, S., Byron, O., Poy, F., Marfatia, S. M., Chishti, A. H., Liddington, R. C. Crystal structure of a PDZ domain. Nature 382, 649-652 (1996)

Optima XL-A, sed. equil., K(d), m; recombinant human Dlg protein PDZ-3 dimer; 30 krpm, 220 and 278 nm, 20deg.C; X-ray crystallography also used; Dept. of Biochemistry, NCMH and Chemistry, Univ. of Leicester, Leicester LE1 7RH, UK

**Calvert, R., Kahana, E., Gratzer, W. B. Stability of the dystrophin rod domain fold: evidence for nested repeating units. Biophys. J. 71, 1605-1610 (1996)

Optima XL-A, sed. equil., M; sed. vel., S; recombinant human dystrophin fragments; 24 and 28 krpm, then 42 krpm (s.e.), 42 or 60 krpm (s.v.); 230 and 280 nm, 5 or 10deg.C; CD and PAGE also used; (Gratzer) MRC Muscle and Cell Motility Unit, King's College, 26-29 Drury Lane, London WC2B 5RL, UK

**Campos-Olivas, R., Bruix, M., Santoro, J., Lacadena, J., Martinez del Pozo, A., Gavilanes, J. G., Rico, M. NMR solution structure of the antifungal protein from Aspergillus giganteus: evidence for cysteine pairing isomerism. Biochemistry 34, 3009-3021 (1995)

Optima XL-A, sed. equil., M(r); Aspergillus giganteus antifungal protein; An-60 Ti, 40 krpm, 280 & 300 nm, 5deg.C; NMR and MS also; effect of salt & conc.; 51 residues; (Rico) Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, Serrano 119, 28006 Madrid, Spain

**Chang, Z., Primm, T. P., Jakana, J., Lee, I. H., Serysheva, I., Chiu, W., Gilbert, H. F., Quiocho, F. A. Mycobacterium tuberculosis 16-kDa antigen (Hsp16.3) functions as an oligomeric structure in vitro to suppress thermal aggregation. J. Biol. Chem. 271, 7218-7223 (1996)

Optima XL-A, sed. equil., m; recombinant mycobacterial 16-kDa antigen; An-60 Ti, 10 krpm, 20deg.C; effect of concentration; light scattering also used; (Quiocho) Howard Hughes Medical Inst., Baylor College of Medicine, Houston, TX 77030

**C^lfen, H., Harding, S. E., Boulter, J. M., Watts, A. Hydrodynamic examination of the dimeric cytoplasmic domain of the human erythrocyte anion transporter, band 3. Biophys. J. 71, 1611-1615 (1996)

Optima XL-A, sed. equil., K(d), M(w); sed. vel., S; human erythrocyte band 3 protein cytoplasmic domain; 10 krpm (s.e.); 3, 5, 10, 15 and 40 krpm (s.v.); 280 nm, 20deg.C; Model E with interference optics used to compare sed. equil. data with XL-A; gel filtration also used; effect of concentration and speed; (Harding) Natl. Centre for Macromolecular Hydrodynamics, Univ. of Nottingham, Sutton Bonington LE12 5RD, UK

**Coffey, R. L., Purich, D. L. Non-cooperative binding of the MAP-2 microtubule-binding region to microtubules. J. Biol. Chem. 270, 1035-1040 (1995)

Optima XL-A, sed. equil., M(r), state of association; recombinant native and mutant MAP-2 microtubule binding region; 16.5 krpm, 256 nm, 23deg.C; (Purich) Dept. of Biochemistry and Molecular Biology, Health Science Center, Gainesville, FL 32610-0245

**Constantine, K. L., Friedrichs, M. S., Metzler, W. J., Wittekind, M., Hensley, P., Mueller, L. Solution structure of an isolated antibody V(L) domain. J. Mol. Biol. 236, 310-327 (1994)

Optima XL-A, sed. equil., K(d); antibody V(L) domain fit to monomer-dimer model; effect of speed (25-45 krpm); NMR also; (Constantine) Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, NJ 08543

**Correia, J. J. Assembly of tubulin dimers into polymers with the Optima XL-A analytical ultracentrifuge. Biophys. J. 66, A294 (1994)

Optima XL-A, technique(s) unspecified; effect of temperature, ionic strength, cations & guanine nucleotides on tubulin polymer assembly; W-Pos246; Dept. of Biochemistry, Univ. of Mississippi Medical Center, 2500 North State St., Jackson, MS 39216

**Darawshe, S., Merezhinskaya, N., Minton, A. P. PhosphorImager enhancement of sedimentation equilibrium-quantitative polyacrylamide gel electrophoresis: a highly sensitive technique for quantitation of equilibrium gradients of individual components in mixtures. Anal. Biochem. 229, 8-14 (1995)

Optima XL-A, sed. equil. in H(2)O-D(2)O, M, v-bar; chicken egg ovalbumin; 10 or 12 krpm, 250 and 280 nm; Edelstein-Schachman method for simultaneous determination of M and v-bar validated for described method using the TL-100 and TLS-55 followed by SDS-PAGE; Laboratories of Biochemical Pharmacology and Cell Biology and Genetics, Natl. Inst. of Diabetes and Digestive and Kidney Diseases, Natl. Inst. of Health, Bethesda, MD 20892

**Darimont, B., Sterner, R. Sequence, assembly and evolution of a primordial ferredoxin from Thermotoga maritima. EMBO J. 13, 1772-1781 (1994)

Optima XL-A, sed. equil., M(r); recombinant holo- and apoferredoxin; 28-56 krpm, 280 or 390 nm for ferredoxin; 38 & 46 krpm, 220 nm for apoferredoxin; PAGE & CD also used; Dept. of Biophysical Chemistry, Biozentrum, Univ. of Basel, CD-4056 Basel, Switzerland

**Davidson, A. R., Sauer, R. T. Folded proteins occur frequently in libraries of random amino acid sequences. Proc. Natl. Acad. Sci. 91, 2146-2150 (1994)

Optima XL-A, sed. equil., M(r); recombinant synthetic QLR proteins; An-60 Ti, 15, 20 or 30 krpm; also CD, fluorescence & gel filtration; Dept. of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139

**Davidson, A. R., Lumb, K. J., Sauer, R. T. Cooperatively folded proteins in random sequence libraries. Nature, Struct. Biol. 2, 856-863 (1995)

Optima XL-A, sed. equil., M(r), degree of oligomerization; random sequence library proteins; 20 or 30 krpm, 25deg.C; GuHCl; CD, gel filtration and NMR also used; 80-residues; (Sauer) Dept. of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139

**Davydov, D. R., Deprez, E., Hoa, G. H. B., Knyushko, T. V., Kuznetsova, G. P., Koen, Y. M., Archakov, A. I. High-pressure-induced transitions in microsomal cytochrome P450 2B4 in solution: evidence for conformational inhomogeneity in the oligomers. Arch. Biochem. Biophys. 320, 330-344 (1995)

Optima XL-A, sed. vel., S, state of aggregation in presence of Triton N-101; rabbit liver cytochrome P450 2B4; An-60 Ti, 420 nm; absorption spectroscopy also used; (Hoa) Institut de Biologie Physico-Chimique, INSERM U.310, Paris, France

**De Young, L. R., Burton, L. E., Liu, J., Powell, M. F., Schmelzer, C. H., Skelton, N. J. RhNGF slow unfolding is not due to proline isomerization: possibility of a cystine knot loop-threading mechanism. Protein Sci. 5, 1554-1566 (1996)

Optima XL-A, sed. equil., m; state of association; recombinant human nerve growth factor; 28 krpm and 30 krpm, 5 and 25deg.C; w/ and w/o GuHCl; fluorescence, NMR and SEC also used; Dept. of Pharmaceutical Research and Development, MS 82, Genentech, 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Ducret, A., Sidler, W., Wehrli, E., Frank, G., Zuber, H. Isolation, characterization and electron microscopy analysis of a hemidiscoidal phycobilisome type from the cyanobacterium Anabaena sp. PCC 7120. Eur. J. Biochem. 236, 1010-1024 (1996)

Optima XL-A, sed. equil., m, state of aggregation; sed. vel., S; cyanobacterial allophycocyanin-II complexes; 2000 rpm (s.e.), 44 krpm (s.v.), 650 nm, 20deg.C; fluorescence, electron microscopy, and PAGE also used; (Zuber) Inst. for Molecular Biology and Biophysics, Federal Inst. of Technology, CH-8093 Zurich, Switzerland

**Easa, A. M., Armstrong, H. J., Mitchell, J. R., Hill, S. E., Harding, S. E., Taylor, A. J. Maillard induced complexes of bovine serum albuminña dilute solution study. Int. J. Biol. Macromol. 18, 297-301 (1996)

Optima XL-A, sed. vel., S, m estimated from S and D (determined by light scattering); bovine serum albumin aggregates; 15-40 krpm, 280 nm, 20deg.C; albumin heated at 95deg.C between 10 and 80 min with and without the presence of xylose; (Hill) Univ. of Nottingham, Dept. of Applied Biochemistry and Food Science, Sutton Bonington Campus, Loughborough, LE12 5RD, UK

**Edwards, S. L., Davidson, V. L., Hyun, Y.-L., Wingfield, P. T. Spectroscopic evidence for a common electron transfer pathway for two tryptophan tryptophylquinone enzymes. J. Biol. Chem. 270, 4293-4298 (1995)

Optima XL-A, sed. equil., m; Alcaligenes faecalis azurin; An-60 Ti, 23 krpm; CD also; (Edwards) Section of Molecular and Cellular Biology, Briggs Hall, Rm. 149, Univ. of California, Davis, CA 95616

Faix, J., Steinmetz, M., Boves, H., Kammerer, R. A., Lottspeich, F., Mintert, U., Murphy, J., Stock, A., Aebi, U., Gerisch, G. Cortexillins, major determinants of cell shape and size, are actin-bundling proteins with a parallel coiled-coil tail. Cell 86, 631-642 (1996)

Optima XL-A, sed. equil., M(r); sed. vel., S; recombinant Dictyostelium discoideum cortexillin I dimer; 12 krpm (s.e.), 56 krpm (s.v.), 230 nm, 20deg.C; CD and electron microscopy also used; Max-Planck-Institut fur Biochemie D-82152 Martinsried, Federal Republic of Germany

**Ferrari, M. E., Lohman, T. M. Apparent heat capacity change accompanying a nonspecific protein-DNA interaction. Escherichia coli SSB tetramer binding to oligodeoxyadenylates. Biochemistry 33, 12896-12910 (1994)

Optima XL-A, sed. equil., S; effect of concentration on Escherichia coli SSB tetramer; 37deg.C, 220 nm; fluorescence also; Dept. Biochem. Mol. Biophysics, Washington Univ. School of Medicine, Box 8231, 660 Sourth Euclid Ave., St. Louis, MO 63110

**Field, C. M., Alberts, B. M. Anillin, a contractile ring protein that cycles from the nucleus to the cell cortex. J. Cell Biol. 131, 165-178 (1995)

Optima XL-A, sed. equil., m; recombinant anillin fragment monomer; effect of conc; (Field) Dept. of Biochemistry and Biophysics, Univ. of California at San Francisco Medical Center, San Francisco, CA 94143-0448

**Fiordalisi, J. J., Grant, G. A. Analytical ultracentrifugation analysis of the self-association of kappa-bungarotoxin. Techniques in Protein Chemistry, Vol. 5, pp. 269-274. Edited by J. W. Crabb. San Diego, Academic Press, 1994.

Optima XL-A, sed. equil., K(d), m; Bungarus multicinctus alpha- and kappa-bungarotoxins; 22 krpm; degree of association; 66-residue polypeptides; Depts. of Medicine and Molecular Biology & Pharmacology, Washington Univ. School. of Medicine, St. Louis, MO 63110

**Fless, G. M., Snyder, M. L., Furbee, J. W., Jr., Garcia-Hedo, M.-T., Mora, R. Subunit composition of lipoprotein(a) protein. Biochemistry 33, 13492-13501 (1994)

Optima XL-A, sed. equil., b.d., M(r); human plasma LDL, lipoprotein(a), reduced and carboxymethylated of apolipoproteins(a) and -(b), and apoB-apo(a) complex; 3-10 krpm, density adjusted with NaBr; GuHCl; (Fless) Dept. of Medicine, Univ. of Chicago, 5841 S. Maryland Ave., Chicago, IL 60637

**Fossati, G., Lucietto, P., Giuliani, P., Coates, A. R., Harding, S., C^lfen, H., Legname, G., Chan, E., Zaliani, A., Mascagni, P. Mycobacterium tuberculosis chaperonin 10 forms stable tetrameric and heptameric structures. Implications for its diverse biological activities. J. Biol. Chem. 270, 26159-26167 (1995)

Optima XL-A, sed. equil., M(r), state of aggregation; E. coli chaperonin 10 and Mycobacterium tuberculosis chaperonin 10 protein and peptides; 20 and 30 krpm, 220, 230 and 280 nm, 20deg.C; CD and SEC also used; (Mascagni) Dept. of Chemistry, Italfarmaco Research Centre, Via Lavoratori; 54, Cinisello Balsamo, 20092 Milan, Italy

**Garcia de Viedma, D., Giraldo, R., Rivas, G., Fernandez-Tresguerres, E., Diaz-Orejas, R. A leucine zipper motif determines different functions in a DNA replication protein. EMBO J. 15, 925-934 (1996)

Optima XL-A, sed. equil., M(w), state of oligomerization; recombinant DNA replication protein RepA monomer-dimer; 20 and 25 krpm, 230 and 280 nm, 4deg.C; effect of concentration; Departamento de Microbiologia Molecular, Centro de Investigaciones Biologicas, CSIC Velazquez 144, 28006 Madrid, Spain

**Gattoni, M., Boffi, A., Sarti, P., Chiancone, E. Stability of the heme-globin linkage in alpha-beta dimers and isolated chains of human hemoglobin. A study of the heme transfer reaction from the immobilized proteins to albumin. J. Biol. Chem. 271, 10130-10136 (1996)

Optima XL-A, sed. equil., K(a), sed. vel., K(a), S; human methemoglobin; 40 krpm (s.v.), 20 krpm (s.e.); 410, 540 or 630 nm; 10 and 20deg.C; (Chiancone) Dept. of Biochemical Sciences "A. Rossi Fanelli," Univ. La Sapienza, 00185 Rome, Italy

**Gibbons, D. L., Horowitz, P. M. Exposure of hydrophobic surfaces on the chaperonin GroEL oligomer by protonation or modification of His-401. J. Biol. Chem. 270, 7335-7340 (1995)

Optima XL-A, sed. vel., S; recombinant chaperonin GroEL oligomer; An-60 Ti, 20 or 27 krpm, effect of pH 5.5; fluorescence also used; 14-mer; Dept. of Biochemistry, Univ. of Texas Health Science Center, San Antonio, TX 78284-7760

**Goldmann, W. H., Bremer, A., Haner, M., Aebi, U., Isenberg, G. Native talin is a dumbbell-shaped homodimer when it interacts with actin. J. Struct. Biol. 112, 3-10 (1994)

Optima XL-A, sed. equil., m; sed. vel., S; human platelet talin; 5200, 6800 & 56 krpm; (Isenberg) Technical Univ. of Munich, Dept. of Biophysics, E22, James Franck Strasse, D-85748 Garching, FRG

**Gorovits, B. M., Horowitz, P. M. The chaperonin GroEL is destabilized by binding of ADP. J. Biol. Chem. 270, 28551-28556 (1995)

Optima XL-A, sed. vel., s distribution, state of oligomerization; recombinant chaperonin GroEL monomers and 14-mers; An-60 Ti, 27-40 krpm, 25deg.C with and without urea; light scattering also used; (Horowitz) Dept. of Biochemistry, Univ. of Texax Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78284

**Gorovits, B., Raman, C. S., Horowitz, P. M. High hydrostatic pressure induces the dissociation of cpn60 tetradecamers and reveals a plastictiy of the monomers. J. Biol. Chem. 270, 2061-2066 (1995)

Optima XL-A, sed. vel., S; Escherichia coli chaperonin Cpn60 monomers and 14-mers; An-60 Ti, 27 & 40 krpm, 10deg.C; pressure-treated protein; fluorescence & PAGE also; Dept. of Biochemistry, Univ. of Texas Health Science Center, San Antonio, TX 78284-7760

**Gorovits, B. M., Seale, J. W., Horowitz, P. M. Residual structure in urea-denatured chaperonin GroEL. Biochemistry 34, 13928-13933 (1995)

Optima XL-A, sed, vel., S; recombinant chaperonin GroEL; An-60 Ti, 27-40 krpm, 25deg.C; effect of urea concentration; CD, fluorescence and light scattering also used; (Horowitz) Dept. of Biochemistry, Univ. of Texas Health Sciences Center at San Antonio, San Antonio, TX 78240-7760

**Grandori, R., Lavoie, T. A., Pflumm, M., Tian, G., Niersbach, H., Maas, W. K., Fairman, R., Carey, J. The DNA-binding domain of the hexameric arginine repressor. J. Mol. Biol. 254, 150-162 (1995)

Optima XL-A, sed. equil., M(r), state of oligomerization; recombinant arginine repressor N-terminal; An-60 Ti, 20, 25, 35 or 40 krpm, 241 or 251 nm; effect of concentration and speed; CD and SEC also used; (Carey) Chemistry Dept., Princeton Univ., Princeton, NJ 08544-1009

**Harding, S. E. Some recent developments in the analytical ultracentrifugation of food proteins. Nahrung 39, 375-395 (1995)

Optima XL-A described along with methods and applications to food protein analysis; also mentioned: Model E, MOM Model 4170, MSE Analytical Mark II and MSE Centriscan; Univ. of Nottingham, Dept. of Applied Biochemistry and Food Science, Sutton Bonington, UK

**Harding, S. E., Horton, J. C., Morgan, P. J. MSTAR: a FORTRAN program for the model independent molecular weight analysis of macromolecules using low speed or high speed sedimentation equilibrium. Analytical Ultracentrifugation in Biochemistry and Polymer Science, pp. 275-294. Edited by S. E. Harding, A. J. Rowe and J. C. Horton. Cambridge, Royal Society of Chemistry, 1992.

Optima XL-A, sed. equil., human IgM(1); MSTARA for data analysis; Univ. of Nottingham, Dept. of Applied Biochemistry and Food Science, Sutton Bonington, LE12 5rd U.K.

**Harris, J. R., Markl, J. Electron microscopy and biochemical characterization of a 350-kDa annular hemolymph protein from the keyhole limpet Megathura crenulata. Eur. J. Biochem. 225, 521-528 (1994)

Optima XL-A, sed. equil., m; sed. vel., S; limpet hemolymph protein; 4-8 krpm (s.e.), 48 krpm (s.v.), 230 & 280 nm; PAGE also; Institute of Zoology, Univ. of Mainz, Germany

**Hatakeyama, T., Furukawa, M., Nagatomo, H., Yamasaki, N., Mori, T. Oligomerization of the hemolytic lectin CEL-III from the marine invertebrate Cucumaria echinata induced by the binding of carbohydrate ligands. J. Biol. Chem. 271, 16915-16920 (1996)

Optima XL-A, sed. vel., S; Cucumaria echinata hemolytic lectin CEL-III monomer and oligomer; An-60 Ti, 60 or 40 krpm, 280 nm, 20deg.C; CD, gel filtration and PAGE also used; Dept. of Applied Chemistry, Faculty of Engineering, Nagasaki Univ., Nagasaki 852, Japan

**Henniker, A., Ralston, G. B. Reinvestigation of the thermodynamics of spectrin self-association. Biophys. Chem. 52, 251-258 (1994)

Optima XL-A, Model E with interference optics, sed. equil., K, delta G, delta H, T delta S; effect of temperature on spectrin self-association; 7 krpm, 18-30deg.C, 280 or 360 nm (XL-A); 7.2 krpm, 18-40deg.C, in presence of metrizamide (Model E); Dept. of Biochemistry, Univ. of Sydney, Sydney, NSW 2006, Australia

**Hensley, P., McDevitt, P. J., Brooks, I., Trill, J. J., Feild, J. A., McNulty, D. E., Connor, J. R., Griswold, D. E., Kumar, N. V., Kopple, K. D., Carr, S. A., Dalton, B. J., Johanson, K. The soluble form of E-selectin is an asymmetric monomer. Expression, purification, and characterization of the recombinant protein. J. Biol. Chem. 269, 23949-23958 (1994)

Optima XL-A, sed. equil., M(r); sed. vel., S, f/f (0); recombinant E-selectin; 15 krpm (s.e.), 60 krpm (s.v.); NMR, MS, SEC & PAGE also used; (Hensley) Dept. of Macromolecular Sciences (UE-0447B), SmithKline Beecham Pharmaceuticals, 709 Swedeland Rd., King of Prussia, PA 19406-0939

**Henzl, M. T., Zhao, H., Saez, C. T. Self-association of CPV3, an avian thymic parvalbumin. FEBS Lett. 375, 137-142 (1995)

Optima XL-A, sed. equil., state of association; sed. vel., S; recombinant thymic parvalbumin apoprotein; An-60 Ti, 25 krpm (s.e.), 40 krpm (s.v.); effect of concentration and Ca(2+) or Mg(2+) ions; Biochemistry Dept., 117 Schweitzer Hall, Univ. of Missouri at Columbia, Columbia, MO 65211

**Herrera, J. E., Correia, J. J., Jones, A. E., Olson, M. O. J. Sedimentation analyses of the salt- and divalent metal ion-induced oligomerization of nucleolar protein B23. Biochemistry 35, 2668-2673 (1996)

Optima XL-A, sed. equil., m; sed. vel., g(s)*, S; recombinant rat nucleolar protein B23 and oligomers; An-60 Ti, 8 and 13 krpm (s.e.), 42 krpm, 280 nm, 25deg.C (corresponding to 24.6deg.C); effect of concentration, salts and divalent metal ions or reducing agents; (Olson) Dept. of Biochemistry, Univ. of Mississippi Medical Ctr., 2500 North State St., Jackson, MS 39216-4505

**Horowitz, P. M., Hua, S., Gibbons, D. L. Hydrophobic surfaces that are hidden in chaperonin Cpn60 can be exposed by formation of assembly-competent monomers or by ionic perturbation of the oligomer. J. Biol. Chem. 270, 1535-1542 (1995)

Optima XL-A, sed. vel., S; Escherichia coli chaperonin Cpn60 tetradecamer and monomers; effect of GuHCl, Gu(2)SO(4) & salt on association state; fluorescence also; Dept. of Biochemistry, Univ. of Texas Health Science Center, San Antonio, TX 78284-7760

**Hunter, M. G., Bawden, L., Brotherton, D., Craig, S., Cribbes, S., Czaplewski, L. G., Dexter, T. M., Drummond, A. H., Gearing, A. H., Heyworth, C. M., Lord, B. I., McCourt, M., Varley, P. G., Wood, L. M., Edwards, R. M., Lewis, P. J. BB-10010: an active variant of human macrophage inflammatory protein-1-alpha with improved pharmaceutical properties. Blood 86, 4400-4408 (1995)

Optima XL-A, sed. equil., m; recombinant macrophage inflammatory proteins BB-10010 and rhMIP-1-alpha; 15 krpm, 230 nm, 25deg.C; SEC also used; British Biotech Pharmaceuticals Ltd., Watlington Road, Oxford, OX4 5LY, UK

**Ingmer, H., Fong, E. L., Cohen, S. N. Monomer-dimer equilibrium of the pSC101 RepA protein. J. Mol. Biol. 250, 309-314 (1995)

Optima XL-A, sed. equil., K(d), m; Escherichia coli plasmid replication protein pSC101 monomer-dimer; 15, 18 and 25 krpm, 280 nm, 5deg.C; effect of concentration and speed; (Cohen) Dept. of Genetics, Rm. M-320, Stanford Univ. School of Medicine, Stanford, CA 94305

**Ishiai, M., Wada, C., Kawasaki, Y., Yura, T. Replication initiator protein RepE of mini-F plasmid: functional differentiation between monomers (initiator) and dimers (autogenous repressor). Proc. Natl. Acad. Sci. 91, 3839-3843 (1994)

Optima XL-A, sed vel., S; recombinant replication initiator protein RepE; 50 krpm; LALLS & SDS-PAGE also; Institute for Virus Research, Kyoto Universiity, Kyoto 606-01, Japan

**Iwasaki, T., Isogai, Y, Iizuka, T., Oshima, T. Sulredoxin: a novel iron-sulfur protein of the thermoacidophilic archaeon Sulfolobus sp. strain 7 with a Rieske-type [2Fe-2S] center. J. Bacteriol. 177, 2576-2582 (1995)

Optima XL-A, sed. equil., state of association (data not shown); bacterial sulredoxin; An-60 Ti, 20 krpm, 20deg.C; CD, mass spectrometry and PAGE also used; GuHCl; Dept. of Life Science, Tokyo Inst. of Technology, Nagatsuta, Yokohama 226, Japan

**Johanson, K., Appelbaum, E., Doyle, M., Hensley, P., Zhao, B., Abdel-Meguid, S. S., Young, P., Cook, R., Carr, S., Matico, R., Cusimano, D., Dul, E., Angelichio, M., Brooks, I., Winborne, E., McDonnell, P., Morton, T., Bennett, D., Sokoloski, T., McNulty, D., Rosenberg, M., Chaiken, I. Binding interactions of human interleukin 5 with its receptor alpha subunit. Large scale production, structural, and functional studies of Drosophila-expressed recombinant proteins. J. Biol. Chem. 270, 9459-9471 (1995)

Optima XL-A, sed. equil., m, stoichiometry; a recombinant human interleukin 5, its receptor alpha subunit and complex; 25deg.C; PAGE, size exclusion chromatrography, mass spectrometry, and filtration microcalorimetry also used; (Chaiken) Dept. of Molecular Immunology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406

**Joss, L. A., Ralston, G. B. beta-Lactoglobulin B: a proposed standard for the study of reversible self-association reactions in the analytical ultracentrifuge? Anal. Biochem. 236, 20-26 (1996)

Optima XL-A, sed. equil., delta G, delta H, delta S, state of association; beef milk beta-lactoglobulin B monomer-dimer; 25-30 krpm, 280 nm, 5-30deg.C; Dept. of Biochemistry, Univ. of Sydney, Sydney, New South Wales 2006, Australia

**Jumel, K., Wilson, S. E., Smith, M. C. M., Harding, S. E. Investigations of the oligometric state of the 42 kDa repressor isoform from the streptomyces temperate bacteriophage phiC31. Progress in Colloid & Polymer Science, Vol. 99, pp. 11-16. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

**Kalinin, N. L., Ward, L. D., Winzor, D. J. Effects of solute multivalence on the evaluation of binding constants by biosensor technology: studies with concanavalin A and interleukin-6 as partitioning proteins. Anal. Biochem. 228, 238-244 (1995)

Optima XL-A, sed. equil., M(w); concanavalin A; 18 krpm, 280 nm, 20deg.C, effect of concentration; BIAcore also used; (Winzor) Center for Protein Structure, Function and Engineering, Dept. of Biochemistry, Univ. of Queensland, Brisbane, QLD 4072, Australia

**Kammerer, R. A., Antonsson, P., Schulthess, T., Fauser, C., Engel, J. Selective chain recognition in the C-terminal alpha-helical coiled-coil region of laminin. J. Mol. Biol. 250, 64-73 (1995)

Optima XL-A, sed. equil., m; sed. vel., S; recombinant laminin fragments and heterodimers; 26 krpm (s.e.), 56 krpm (s.v.), 230 and 277 nm, 20deg.C; CD and PAGE also used; (Engel) Dept. of Biophysical Chemistry, Biozantrum Klingelburgstrasse 70 CH-4056 Basel, Switzerland

**Keown, M. B., Ghirlando, R., Young, R. J., Beavil, A. J., Owens, R. J., Perkins, S. J., Sutton, B. J., Gould, H. J. Hydrodynamic studies of a complex between the Fc fragment of human IgE and a soluble fragment of the Fc-epsilon-RI alpha chain. Proc. Natl. Acad. Sci. 92, 1841-1845 (1995)

Optima XL-A, sed. equil., M(b); sed. vel., S; recombinant human IgE, its Fc-epsilon-RI receptor fragment, and complex; 11-17 krpm & 18-22 krpm (s.e.); 40 & 50 krpm (s.v.); 280 nm; PAGE also used; (Gould) The Randall Institute, King's College London, 26-29 Drury Lane, London WC2B 5RL, UK

**Krebs, A., Kuchumov, A. R., Sharma, P. K., Braswell, E. H., Zipper, P., Weber, R. E., Chottard, G., Vinogradov, S. N. Molecular shape, dissociation, and oxygen binding of the dodecamer subunit of Lumbricus terrestris hemoglobin. J. Biol. Chem. 271, 18695-18704 (1996)

Optima XL-A, sed. equil., m, state of dissociation; sed. vel., S; earthworm hemoglobin dodecamer subunit; 10 or 14 krpm, 1deg.C or 25deg.C, 280, 418 or 540 nm; 55 krpm, 1deg.C, 25deg.C or 40deg.C, 280, 310 or 412 nm; in presence of urea or SiW; X-ray scattering also used; (Vinogradov) Biochemistry Dept., Wayne State Univ. School of Medicine, Detroit, MI 48201

**Krylov, D., Mikhailenko, I., Vinson, C. A thermodynamic scale for leucine zipper stability and dimerization specificity: e and g interhelical interactions. EMBO J. 13, 2849-2861 (1994)

Optima XL-A, sed. equil., m (no data given); effect of temperature on leucine zipper coiled-coil proteins associative states; An-60 Ti, 25 krpm, effect of conc. also; CD also used; Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892

**Ladjimi, M. M., Benaroudj, N., Batelier, G., Triniolles, F. Self-association of the molecular chaperone HSC 70 as assessed by analytical ultracentrifugation. Progress in Colloid & Polymer Science, Vol. 99, pp. 1-6. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A, sed. equil., K(a), M(w); sed. vel., S; recombinant chaperone heat shock cognate protein; An-60 Ti, 8, 12 and 16 krpm (s.e.), 60 krpm (s.v.), 280 nm, 4 and 20deg.C; effect of concentration; Laboratoire d'Enzymologie, C.N.R.S. 91198 Gif-sur-Yvette Cedex, France

**Ladror, U. S., Snyder, S. W., Wang, G. T., Holzman, T. F., Krafft, G. A. Cleavage at the amino and carboxyl termini of Alzheimer's amyloid-beta by cathepsin D. J. Biol. Chem. 269, 18422-18428 (1994)

Optima XL-A, sed. vel., S; amyloid-beta 1-40 and 1-42 fragments; 30 or 6 krpm, pH 3.5, 280 nm; (Holzman) Dept. 46Y, AP-10, Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, IL 60064

**Lai, Z., Colon, W., Kelly, J. W. The acid-mediated denaturation pathway of transthyretin yields a conformational intermediate that can self-assemble into amyloid. Biochemistry 35, 6470-6482 (1996)

Optima XL-A, sed. equil., m; recombinant human transthyretin; 17 krpm, 234 nm, 25deg.C; CD, fluorescence and PAGE also used; (Kelly) Dept. of Chemistry, Texas A & M Univ., College Station, TX 77843-3255

**Laue, T. M., Starovasnik, M. A., Weintraub, H., Sun, X.-H., Snider, L., Klevit, R. E. MyoD forms micelles which can dissociate to form heterodimers with E47: implications of micellization on function. Proc. Natl. Acad. Sci. 92, 11824-11828 (1995)

Optima XL-A, sed. vel., G(s*), g(s*); Model E with on-line interference optics, sed. equil., M(r), state of aggregation; recombinant DNA-binding transcription factor MyoD, E47, and heterodimer complexes; An-60 Ti, 10, 20, 48 and 60 krpm, 20deg.C or 36deg.C, effect of temperature (s.v.); 23.3deg.C (s.e.); Dept. of Biochemistry and Molecular Biology, Life Sciences Bldg., Univ. of New Hampshire, Durham, NH 03824-3544

**Lee, G. J., Pokala, N., Vierling, E. Structure and in vitro molecular chaperone activity of cytosolic small heat shock proteins from pea. J. Biol. Chem. 270, 10432-10438 (1995)

Optima XL-A, sed. equil., m; recombinant small heat shock protein oligomers; An-60 Ti, 7-15 krpm; (Lee) Dept. of Biochemistry, Univ. of Arizona, Tucson, AZ 85721

**Liu, J., Lester, P., Builder, S., Shire, S. J. Characterization of complex formation by humanized anti-IgE monoclonal antibody and monoclonal human IgE. Biochemistry 34, 10474-10482 (1995)

Optima XL-A, sed. equil., M(w); sed. vel., g(s)*, S; monoclonal IgE, humanized anti-IgE monoclonal antibody and their complexes; 5, 7 and 10 krpm (s.e.), 60 krpm (s.v.), 10deg.C; size exclusion chromatography also used; hydrodynamic models; (Shire) Pharmaceutical Research and Development and Recovery Process Research and Development, Genentech, Inc., South San Francisco, CA 94080

**Lu, H. S., Chang, D., Philo, J. S., Zhang, K., Narhi, L. O., Liu, N., Zhang, M., Sun, J., Wen, J., Yanagihara, D., Karunagaran, D., Yarden, Y., Ratzkin, B. Studies on the structure and function of glycosylated and nonglycosylated neu differentiation factors. Similarities and differences of the alpha and beta isoforms. J. Biol. Chem. 270, 4784-4791 (1995)

Optima XL-A, sed. equil., M; sed. vel., S; recombinant human or rat neu differentiation factors; 15 & 21 krpm (s.e.), 60 krpm (s.v.), 280 nm, 20deg.C; effect of conc.; CD, gel filtration, light scattering & PAGE; (Lu) Amgen Inc., Amgen Center, 1840 DeHavilland Dr., Thousand Oaks, CA 91320-1789

**Mach, H., Ryan, J. A., Burke, C. J., Volkin, D. B., Middaugh, C. R. Partially structured self-associating states of acidic fibroblast growth factor. Biochemistry 32, 7703-7711 (1993)

Optima XL-A, sed. equil.,v-bar; sed. vel., S; method did not detect changes in v-bar and S due to unfolding at acid pH (these were detected by SEC); effect of pH; recombinant acidic fibroblast growth factor; 30 & 37 krpm (s.e.); 50 krpm (s.v.); CD, fluorescence, IR & SEC also used; Dept. of Pharmaceutical Research, Merck Research Laboratories, WP78-302, West Point, PA 19486

**Malchiodi, E. L., Eisenstein, E., Fields, B. A., Ohlendorf, D. H., Schlievert, P. M., Karjalainen, K., Mariuzza, R. A. Superantigen binding to a T cell receptor beta chain of known three-dimensional structure. J. Exp. Med. 182, 1833-1845 (1995)

Optima XL-A, sed. equil., K(d), M; recombinant T-cell receptor beta-chain, bacterial toxin superantigens, and their complexes; An 55, 22-30 krpm, 20-25deg.C; BIAcore also used and K(d)s compared with XL-A data; (Mariuzza) Center for Advanced Research in Biotechnology, 9600 Gudelsky Dr., Rockville, MD 20850

**Malencik, D. A., Anderson, S. R. Dityrosine formation in calmodulin: conditions for intermolecular cross-linking. Biochemistry 33, 13363-13372 (1994)

Optima XL-A, sed. equil., M, state of association; sed. vel., S; photoactivated beef brain calmodulin dimer; 15 krpm (s.e.), 40 krpm (s.v.), 240-315 nm; 21.1deg.C; Dept. of Biochem. and Biophys., Oregon State Univ., Corvalis, OR 97331-7305

**Malencik, D. A., Anderson, S. R. Dityrosine formation in calmodulin: cross-linking and polymerization catalyzed by Arthromyces peroxidase. Biochemistry 35, 4375-4386 (1996)

Optima XL-A, sed. equil., M; sed. vel., S, s distribution; beef brain calmodulin, crosslinked and polymerized; 3600 or 5200 rpm (s.e.), 35 krpm (s.v.), 280 nm, 4deg.C or 21.1deg.C; fluorescence, gel filtration and PAGE also used; (Anderson) Dept. of Biochemistry and Biophysics, Oregon State Univ., Corvallis, OR 97331-7305

**Markovic-Housley, Z., Cooper, A., Lustig, A., Flukiger, K, Stolz, B., Erni, B. Independent folding of the domains in the hydrophilic subunit IIAB(man) of the mannose transporter of Escherichia coli. Biochemistry 33, 10977-10984 (1994)

Optima XL-A, sed. equil., m, sed. vel., S; effect of GuHCl concentration on mannose transporter subunits; 52 krpm (s.v.), 13-36 krpm (s.e.); CD, fluorescence & diff. calorimetry also; (Markovic-Housley) Institut fur Biochemie, Universitat Bern, Freiestrasse 3, CH-3012 Bern, Switzerland

**Mayer, E. J., McKenna, E., Garsky, V. M., Burke, C. J., Mach, H., Middaugh, C. R., Sardana, M., Smith, J. S., Johnson, R. G., Jr. Biochemical and biophysical comparison of native and chemically synthesized phospholamban and a monomeric phospholamban analog. J. Biol. Chem. 271, 1669-1677 (1996)

Optima XL-A, sed. vel., S, state of association; synthetic or dog heart membrane protein phospholamban and analog; An-60 Ti, 47 krpm, 20deg.C; CD, mass spectrometry and PAGE also used; (Johnson, Jr.) Merck Research Laboratories, Dept. of Pharmacology, WP44-L206, West Point, PA 19486

**Melki, R., Rommelaere, H., Leguy, R., Vandekerckhove, J., Ampe, C. Cofactor A is a molecular chaperone required for beta-tubulin folding: functional and structural characterization. Biochemistry 35, 10422-10435 (1996)

Optima XL-A, sed. equil., M; beef testis cofactor A; An-60 Ti, 40 krpm, 278 nm, 20deg.C; CD and PAGE also used; Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette, France

**Milla, M. E., Sauer, R. T. P22 arc repressor: folding kinetics of a single-domain, dimeric protein. Biochemistry 33, 1125-1133 (1994)

Optima XL-A, sed. equil., M(w); effect of pH on E. coli P22 Arc repressor protein (monomer & dimer); 27 & 39 krpm; fluorescence also; Dept. of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139

**Morgan, P. J., Byron, O. D., Harding, S. E. The solution conformation of novel antibody fragments studied using the Optimaô XL-A analytical ultracentrifuge. Technical Information DS-834. Palo Alto, Calif., Beckman Instruments, Inc., Spinco Division, 1992.

Optima XL-A, sed. equil. & sed. vel.; M, S of monoclonal antibody Fab' (Fab')(2) fragments; monodispersity and lack of self-association confirmed; 278 nm; Beckman Instruments, Inc., Spinco Business Unit, P.O. Box 10200, Palo Alto, California 94304.

**Morgan, P. J., Varley, P. G., Rowe, A. J., Andrew, P. W., Mitchell, T. J. Characterization of the solution properties and conformation of pneumolysin, the membrane-damaging toxin of Streptococcus pneumoniae. Biochem. J. 296, 671-674 (1993)

Optima XL-A, sed. equil., M(r); sed. vel., S; recombinant bacterial pneumolysin; CD and fluorescence also; (Morgan) Dept. of Microbiology, Univ. of Leicester, Leicester LE1 9HN, U.K.

**Munson, M., Balasubramanian, S., Fleming, K. G., Nagi, A. D., O'Brien, R., Sturtevant, J. M., Regan, L. What makes a protein a protein? Hydrophobic core designs that specify stability and structural properties. Protein Sci. 5, 1584-1593 (1996)

Optima XL-A, sed. equil., sed. vel., state of association; recombinant ROP protein mutants; 20-40 krpm (s.e.), 60 krpm (s.v.), 25deg.C; CD, NMR, and calorimetry also used; (Regan) Dept. of Molecular Biophysics and Biochemistry, 266 Whitney Ave., New Haven, CT 06520-8114

**Nagahora, H., Harata, K., Muraki, M., Jigami, Y. Site-directed mutagenesis and sugar-binding properties of the wheat germ agglutinin mutants Tyr73Phe and Phe116Tyr. Eur. J. Biochem. 233, 27-34 (1995)

Optima XL-A, sed. equil., K(a), m; wheat germ agglutinins and binding of N-acetylglucosamine;16 krpm, 280 nm; (Jigami) Molecular Biology Dept., National Institute of Bioscience and Human Technology, 1-1 Higashi, Tsukuba, Ibaraki, Japan 305

**Narhi, L. O., Rosenfeld, R., Wen, J., Arakawa, T., Prestrelski, S. J., Philo, J. S. Acid-induced unfolding of brain-derived neurotrophic factor results in the formation of a monomeric "A state." Biochemistry 32, 10819-10825 (1993)

Optima XL-A, sed. vel., S; effect of acid denaturation on compactness of recombinant human brain-derived neurotrophic factor monomer & dimer; also CD, SEC, fluorescence, IR & light scattering; Protein Chemistry Dept., Amgen Inc., Amgen Center, Thousand Oaks, CA 91320

**Narhi, L. O., Philo, J. S., Li, T., Zhang, M., Samal, B., Arakawa, T. Induction of alpha-helix in the beta-sheet protein tumor necrosis factor-alpha: thermal and trifluoroethanol-induced denaturation at neutral pH. Biochemistry 35, 11447-11453 (1996)

Optima XL-A, sed. equil., state of association; recombinant human or murine tumor necrosis factor-alpha monomer-trimer; 10, 14 and 20 krpm, 230 or 280 nm, 25deg.C; effect of concentration; CD also used; Amgen Inc., Amgen Center, M/S 14-2-D, Thousand Oaks, CA 91320-1789

**Narhi, L. O., Philo, J. S., Li, T., Zhang, M., Samal, B., Arakawa, T. Induction of alpha-helix in the beta-sheet protein tumor necrosis factor-alpha: acid-induced denaturation. Biochemistry 35, 11454-11460 (1996)

Optima XL-A, sed. vel., D, g(s*), M(r), S; recombinant human or murine tumor necrosis factor-alpha monomer-trimer; 60 krpm, 230 nm, 20deg.C; effect of pH; CD and FTIR also used; Amgen Inc., Amgen Center, M/S 14-2-D, Thousand Oaks, CA 91320-1789

**Nemeth, A., Krause, S., Blank, D., Jenny, A., Jen^, P., Lustig, A., Wahle, E. Isolation of genomic and cDNA clones encoding bovine poly(A) binding protein II. Nucleic Acids Res. 23, 4034-4041 (1995)

Optima XL-A, sed. equil., m; sed. vel., S; recombinant beef poly(A)-binding protein II; 20 and 28 krpm (s.e.), 56 krpm (s.v.), 20deg.C; PAGE also used; state of association. (Wahle) Universitat Giessen, Institut fur Biochemie, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany

**Norcum, M. T. Novel isolation method and structural stability of a eukaryotic chaperonin: the TCP-1 ring complex from rabbit reticulocytes. Protein Sci. 5, 1366-1375 (1996)

Optima XL-A, sed. vel., S; rabbit reticulocyte chaperonin; 30 krpm, 24.6deg.C; EM, fluorescence and PAGE also used; Dept. of Biochemistry, Univ. of Mississippi Medical Center, Jackson, MS 39216-4505

**Obermann, W. M. J., Plessmann, U., Weber, K., Furst, D. O. Purification and biochemical characterization of myomesin, a myosin-binding and titin-binding protein, from bovine skeletal muscle. Eur. J. Biochem. 233, 110-115 (1995)

Optima XL-A, S; sed. vel., S; beef skeletal muscle myomesin; An-60; CD also used; (Furst) Max-Planck-Institute for Biophysical Chemistry, Dept. of Biochemistry, P.O. Box 2841, D-37077 G^ttingen, Germany

**Okino, N., Kawabata, S., Saito, T., Hirata, M., Takagi, T., Iwanaga, S. Purification, characterization, and cDNA cloning of a 27-kDa lectin (L10) from horseshoe crab hemocytes. J. Biol. Chem. 270, 31008-31015 (1995)

Optima XL-A, sed. equil., state of oligomerization; recombinant lectin L10b monomer; 14 krpm, 4deg.C; fluorescence also used; (Iwanaga) Dept. of Biology, Faculty of Science, Kyushu Univ. 33, Fukuoka 812-81, Japan

**Paolini, J. F., Willard, D., Consler, T., Luther, M., Krangel, M. S. The chemokines IL-8, monocyte chemoattractant protein-1, and I-309 are monomers at physiologically relevant concentrations. J. Immunol. 153, 2704-2717 (1994)

Optima XL-A, sed. equil., K(a) associative state; recombinant interleukin-8 monomer-dimer, monocyte chemoattractant protein-1 monomer-dimer, and I-309; effect of 15-, 20- and 25-krpm; 280 nm; (Krangel) Dept. of Immunology, PO Box 3010, Duke Univ. Medical Center, Durham, NC 27710

**Pascual, J., Pfuhl, M., Rivas, G., Pastore, A., Saraste, M. The spectrin repeat folds into a three-helix bundle in solution. FEBS Lett. 383, 201-207 (1996)

Optima XL-A, sed. equil., M(w); recombinant chicken brain alpha-subunit; An-60 Ti; 30 krpm, 280-300 nm, 25deg.C; effect of concentration; NMR also used; (Saraste) European Molecular Biology Laboratory, Meyerhofstr. 1, Postfach 102209, D-69012 Heidelberg, Germany

**Patel, S. R., Evans, S., Dunne, K., Knight, G. C., Morgan, P. J., Varley, P. G., Craig, S. Characterization of the quaternary structure and conformational properties of the human stem cell inhibitor protein LD78 in solution. Biochemistry 32, 5466-5471 (1993)

Optima XL-A, sed. equil., effect of various buffers on M(w); recombinant stem cell inhibitor protein LD78; SEC, CD & fluorescence also used; 278 nm; (Craig) British Bio-technology Ltd., Watlington Rd., Cowley, Oxford, OX4 5LY, U.K.

**Pei, G., Laue, T. M., Aulabaugh, A., Fowlkes, D. M., Lentz, B. R. Structural comparisons of meizothrombin and its precursor prothrombin in the presence or absence of procoagulant membranes. Biochemistry 31, 6990-6996 (1992)

Optima XL-A, sed. vel., g*(s), S; Model E with interference optics, M(z); effect of concentration and speed; beef or recombinant mutant prothrombin or meizothrombin; 10-32 krpm (s.e.), 60 krpm (s.v.)

**Peng, Z., Kim, P. S. A protein dissection study of a molten globule. Biochemistry 33, 2136-2141 (1994)

Optima XL-A, sed. equil., m; human alpha-lactalbumin and its alpha-domain(ox); An-60 Ti, 25-33 krpm; CD, fluorescence, NMR & dynamic LS also used; Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Dept. of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142

**Peng, Z., Wu, L. C., Kim, P. S. Local structural preferences in the alpha-lactalbumin molten globule. Biochemistry 34, 3248-3252 (1995)

Optima XL-A, sed. equil., M(app); alpha-lactalbumin; 25 & 30 krpm; 230-285 nm; effect of concentration; CD also; Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Dept. of Biology, MIT, Nine Cambridge Center, Cambridge, MA 02142

**Pennica, D., Lam, V. T., Weber, R. F., Kohr, W. J., Basa, L. J., Spellman, M. W., Ashkenazi, A., Shire, S. J., Goeddel, D. V. Biochemical characterization of the extracellular domain of the 75-kilodalton tumor necrosis factor receptor. Biochemistry 32, 3131-3138 (1993)

Optima XL-A, sed. equil., M(r); recombinant human tissue factor-alpha, -beta, receptor, and complexes; 15 krpm, 235 nm; Depts. of Molecular Biology, Protein Chemistry, Medicinal and Analytical Chemistry, Pulmonary Research, and Pharmaceutical Research and Development, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Perelroizen, I., Marchand, J.-B., Blanchoin, L., Didry, D., Carlier, M.-F. Interaction of profilin with G-actin and poly(L-proline). Biochemistry 33, 8472-8478 (1994)

Optima XL-A, sed. vel., S; G-actin, profilin, and profilin-actin complex; 60 krpm, 280 nm; fluorescence & stopped-flow kinetics also; Laboratoire d'Enzymologie, CNRS, 91190 Gif-sur-Yvette Cedex, France

**Peteranderl, R., Nelson, H. C. M. Trimerization of the heat shock transcription factor by a triple-stranded alpha-helical coiled-coil. Biochemistry 31, 12272-12276 (1992)

Optima XL-A, sed. equil., M; sed. vel., S; Kluyveromyces lactis and Saccharomyces cerevisiae heat shock transcription factor fragments; 15 krpm (s.e.) and 60 krpm (s.v.); 2-100 micron conc.; also CD and light scattering

**Phillips, M. L., Lembertas, A. V., Schumaker, V. N., Lawn, R. M., Shire, S. J., Zioncheck, T. F. Physical properties of recombinant apolipoprotein(a) and its association with LDL to form an Lp(a)-like complex. Biochemistry 32, 3722-3728 (1993)

Optima XL-A, sed. equil., M; Model E with Scanner, sed. vel., D, f/f (0), S, Stokes' radius; recombinant apolipoprotein(a); 48 krpm (s.v.), 6.4 krpm (diff); effect of concentration; 10% dimer; (Schumaker) Dept. of Chemistry and Biochemistry and the Molecular Biology Institute, Univ. of California, Los Angeles, CA 90024

**Philo, J. S. Measuring sedimentation, diffusion, and molecular weights by direct fitting of sedimentation velocity concentration profiles. Modern Analytical Ultracentrifugation, pp. 156-170. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A, sed. vel., D, m, S; recombinant brain-derived neurotrophic growth factor, transforming growth factor alpha and bovine serum albumin; Protein Chemistry Dept. 14-2-A-223, Amgen, Inc., Amgen, Inc., Amgen Center, Thousand Oaks, CA 91320

**Ralston, G., Cronin, T. J., Branton, D. Self-association of spectrin's repeating segments. Biochemistry 35, 5257-5263 (1996)

Optima XL-A, Model E with interference optics, sed. equil., M(r); sed. vel., f/f(0), S; recombinant spectrin monomers and dimers; various speeds, 225-280 nm, 4, 30 and 37deg.C, PAGE also used; Dept. of Biochemistry, Univ. of Sydney, Sydney, NSW 2006, Australia

**Redowicz, M. J., Martin, B., Zolkiewski, M., Ginsburg, A., Korn, E. D. Effects of phosphorylation and nucleotides on the conformation of myosin II from Acanthamoeba castellanii. J. Biol. Chem. 269, 13558-13563 (1994)

Optima XL-A, diff. sed. vel., delta s, S; amoeba monomeric myosin II; Model E, schlieren optics, diff. sed. vel., delta s, S; filamentous and monomeric myosin; phosphorylated & dephosphorylated myosins; 280 or 232 nm; (Korn) Laboratory of Cell Biology, National Institutes of Health, Bethesda, MD 20892

**Rety, S., Futterer, K., Grucza, R. A., Munoz, C. M., Frazier, W. A., Waksman, G. pH-dependent self-association of the Src homology 2 (SH2) domain of the Src homologous and collagen-like (SHC) protein. Protein Sci. 5, 405-413 (1996)

Optima XL-A, sed. equil., M, state of association; recombinant Src homologous and collagen-like (SHC) protein domain dimer; 25, 30 and 35 krpm, 280 nm, 5deg.C; PAGE and X-ray crystallography also used; Washington Univ. School of Medicine, Dept. of Biochemistry and Molecular Biophysics, St. Louis, MO 63110

**Rice, P., GarduÒo, R., Itoh, T., Katagiri, C., Ausio, J. Nucleoplasmin-mediated decondensation of Mytilus sperm chromatin. Identification and partial characterization of a nucleoplasmin-like protein with sperm-nuclei decondensing activity in Mytilus californianus. Biochemistry 34, 7563-7568 (1995)

Optima XL-A, sed. vel., S; Mytilus californianus, nucleoplasmin-like protein; An-60 Ti, 44 krpm, 20 , 230 nm; PAGE also used; (Ausio), Dept. of Biochemistry and Microbiology, Univ. of Victoria, Victoria, BC, Canada V8W 3P6

**Ries, A., Engel, J., Lustig, A., Kuhn, K. The function of the NC1 domains in type IV collagen. J. Biol. Chem. 270, 23790-23794 (1995)

Optima XL-A, sed. equil., m; sed. vel., S; human placenta collagen type IV collagen NCI domain hexamers and dimer-monomer complexes; An-D, 9-22 krpm (s.e.), 56 krpm (s.v.), 20deg.C; PAGE also used; (Kuhn) Max-Planck-Institut fur Biochemie, D-82152 Martinsried b. Munchen, Germany

**Rivas, G., Tangemann, K., Minton, A. P., Engal, J. Binding of fibrinogen to platelet integrin alpha-IIb-beta-3 in solution as monitored by tracer sedimentation equilibrium. J. Mol. Recognit. 9, 31-38 (1996)

Optima XL-A, tracer sed. equil., K(d); integrin alpha-IIb-beta-3ñfibrinogen binding; 3-10 krpm, 280-290 nm or 495-550 nm, 10deg.C; with and without detergent; electron microscopy also used; Centro de Investigaciones Biologicas, CSIC, Velazquez 144, 28006-Madrid, Spain

**Robinson, C. R., Sauer, R. T. Covalent attachment of Arc repressor subunits by a peptide linker enhances affinity for operator DNA. Biochemistry 35, 109-116 (1996)

Optima XL-A, sed. equil., m, state of association; recombinant Arc-L1-Arc protein; 15 or 25 krpm; 222, 236 or 280 nm; 25deg.C; CD also used; (Sauer) Dept. of Biology, Massachusetts Inst. of Technology, Cambridge, MA 02139-4307

**Rosenfeld, R., Philo, J. S., Haniu, M., Stoney, K., Rohde, M. F., Wu, G.-M., Narhi, L. O., Wong, C., Boone, T., Hawkins, N. N., Miller, J. M., Arakawa, T. Sites of iodination in recombinant human brain-derived neurotrophic factor and its effect on neurotrophic activity. Protein Sci. 2, 1664-1674 (1993)

Optima XL-A, sed. equil., M; recombinant human brain neurotrophic factor native and iodinated dimers; An-60 Ti, 20 & 28 krpm, 280 nm; also used CD, GPC/LALLS, mass spec.; Amgen Inc., Amgen Center, Thousand Oaks, CA 91320-1789

**Rosenfeld, S. S., Rener, B., Correia, J. J., Mayo, M. S., Cheung, H. C. Equilibrium studies of kinesin-nucleotide intermediates. J. Biol. Chem. 271, 9473-9482 (1996)

Optima XL-A, sed. vel., S; recombinant human kinesin; An-60 Ti, 42 krpm, 232-237 or 280 nm, 24.6deg.C; sed. equil. data to be reported later; Airfuge also used; Dept. of Neurology, Univ. of Alabama at Birmingham, UAB Station, 510 Medical Education Bldg., Birmingham, AL 35294-0007

**Saez, C. T., Jansen, G. J., Smith, A., Morgan, W. T. Interaction of histidineñproline-rich glycoprotein with plasminogen: effect of ligands, pH, ionic strength, and chemical modification. Biochemistry 34, 2496-2503 (1995)

Optima XL-A, sed. equil., K(d), M; FITC-plasminogen interaction with histidineñproline-rich glycoprotein; An-60 Ti, 10 krpm & 30-10 krpm, 495 nm; effect of temperature (25-4deg.C; sucrose gradient centrifugation (VTi 80) also used; (Morgan) Univ. of MissouriñKansas City, Division of Biochemistry and Molecular Biology, School of Biological Sciences, Kansas City, Missouri 64110

**Sanyal, G., Marquis-Omer, D., Gress, J. O., Middaugh, C. R. A transforming growth factor-alpha-Pseudomonas exotoxin hybrid protein undergoes pH-dependent conformational changes conducive to membrane interaction. Biochemistry 32, 3488-3497 (1993)

Optima XL-A, sed. equil, M; sed. vel., S; effect of pH on chimeric protein TP40 association; 10-40 krpm; Nonlin; CD, fluorescence & light scattering also used; Dept. of Pharmaceutical Research, WP 26-331, Merck Research Laboratories, West Point, PA 19486

**Sch^nfeld, H.-J., Schmidt, D., Schr^der, H., Bukau, B. The DnaK chaperone system of Escherichia coli: quaternary structures and interactions of the DnaK and GrpE components. J. Biol. Chem. 270, 2183-2189 (1995)

Optima XL-A, sed. equil., m; sed. vel., S; Escherichia coli heat shock proteins DnaK, GrpE, and their complex; 40 krpm (s.v.), 7 krpm (s.e.), 20deg.C; light scattering, gel filtration & PAGE also used; (Sch^nfeld) Hoffmann-La Roche Limited, Pharmaceutical Research-New Technologies, CD-4002 Basel, Switzerland

**Sch^nfeld, H.-J., Schmidt, D., Zulauf, M. Investigation of the molecular chaperone DnaJ by analytical ultracentrifugation. Progress in Colloid & Polymer Science, Vol. 99, pp. 7-10. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A, sed. equil., state of oligomerization; recombinant molecular chaperone DnaJ; 7000 or 9000 rpm; effect of pH 5.5, 7.7 and 9.5; 10 or 20deg.C; Hoffmann-La Roche Limited Pharmaceutical Research-New Technologies, 4002 Basel, Switzerland

**Schubert, D., Tziatzios, C., van den Broek, J. A., Schuck, P., Germeroth, L., Michel, H. Determination of the molar mass of pigment-containing complexes of intrinsic membrane proteins: problems, solutions and application to the light-harvesting complex B800/820 of Rhodospirillum molischianum. Progress in Colloid & Polymer Science, Vol. 94, pp. 14-19. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil, m, v-bar; Rhodospirillum molischianum light harvesting protein-pigment complex oligomers in various detergent solutions; 15-25 krpm, 357 or 370 nm, 6deg.C; Institut fur Biophysik der Johann Wolfgang Goethe-Universitat and Max-Planck-Institut fur Biophysik, Frankfurt am Main, FRG

**Schuck, P. Simultaneous radial and wavelength analysis with the Optima XL-A analytical ultracentrifuge. Progress in Colloid & Polymer Science, Vol. 94, pp. 1-13. Edited by M. D. Lechner. Darmstadt, Steinkopf, 1994.

Optima XL-A, sed. equil., extinction profiles, M(r); human erythrocyte band 3 protein, DBDS nonionic detergent and oxyhemoglobin mixtures studied as model systems; 11-12,500 rpm; mathematical analysis described; 4 , 270-340 nm; Institut fur Biophysik der Johann Wolfgang Goethe-Universitat and Max-Planck-Institut fur Biophysik, Frankfurt am Main, FRG

**Schuck, P., Legrum, B., Passow, H., Schubert, D. The influence of two anion-transport inhibitors, 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonate and 4,4'-dibenzoylstilbene-2,2'-disulfonate, on the self-association of erythrocyte band 3 protein. Eur. J. Biochem. 230, 806-812 (1995)

Optima XL-A, sed. equil., state of association; human erythrocyte membrane band 3 protein and its interactions with stilbenedisulfonates; 9-12.5 krpm, 4deg.C, 280 nm; (Schubert) Institut fur Biophysik der J. W. Goethe-Univ. Theodor-Stern-Kai 7, Haus 74, D-60590 Frankfurt am Main, Germany

**Seale, J. W., Horowitz, P. M. The C-terminal sequence of the chaperonin GroES is required for oligomerization. J. Biol. Chem. 270, 30268-30270 (1995)

Optima XL-A, sed. vel., S, state of oligomerization; recombinant truncated chaperonin GroES; 60 krpm, 25deg.C; (Horowitz) Dept. of Biochemistry, Univ. of Texas Health Sciences Center, San Antonio, TX 78240-7760

**Seale, J. W., Gorovits, B. M., Ybarra, J., Horowitz, P. M. Reversible oligomerization and denaturation of the chaperonin GroES. Biochemistry 35, 4079-4083 (1996)

Optima XL-A, sed. vel., S, state of oligomerization; native, denatured and renatured Escherichia coli chaperonin GroES; 40 krpm, 230 nm, 25deg.C; fluorescence also used; effect of urea; (Horowitz) Dept. of Biochemistry, Univ. of Texas Health Sciences Center at San Antonio, San Antonio, TX 78240-7760

**Seifert, A., Heinevetter, L., C^lfen, H., Harding, S. E. Characterization of gliadin-galactomannan incubation mixtures by analytical ultracentrifugation. Part I. Sedimentation velocity. Carbohydr. Polym. 28, 325-332 (1995)

Optima XL-A, sed. equil., M(w); wheat gliadin and locust bean galactomannan; Model E and MOM 3170B analytical ultracentrifuge with schlieren optics, S; gliadin, galactomannan and their interaction; 10 and 15 krpm, 220 and 230 nm (XL-A); PAGE also used; German Institute for Human Nutrition, Arthur-Scheunert-Allee 114-116, D-14558 Bergholz-Rehbrucke, Germany

**Silkowski, H., Byron, O., Davis, S. J., Barclay, A. N., Davies, E. A., Rowe, A. J., Harding, S. E. Estimation of the dissociation constant of the cell adhesion molecules srCD2 and srCD48 using analytical ultracentrifugation. Biochem. Soc. Trans. 23, 435S (1995)

Optima XL-A, sed. equil., sed. vel., M(w), S, K(d); cell adhesion molecules; no exptl. detail; abstract only; K(d) values compared with BIAcore data; National Centre for Macromolecular Hydrodynamics, Dept. of Biochemistry, Leicester Univ., University Rd., Leicester, LE1 7RH, UK

**Smith, S. V., Correia, J. J., Case, S. T. Disulfide bonds in a recombinant protein modeled after a core repeat in an aquatic insect's silk protein. Protein Sci. 4, 945-954 (1995)

Optima XL-A, sed. equil., M; recombinant silk protein; An-60 Ti, 48 krpm, 25deg.C; effect of concentration; mass spectrometry & PAGE also used; Univ. of Mississippi Medical Ctr., Dept. of Biochemistry, Jackson, Miss. 39216-4505

**Staley, J. P., Kim, P. S. Formation of a native-like subdomain in a partially folded intermediate of bovine pancreatic trypsin inhibitor. Protein Sci. 3, 1822-1832 (1994)

Optima XL-A, sed. equil., m; native and recombinant analog of bovine pancreatic-trypsin inhibitor; 37, 41 & 45 krpm; 249, 261 & 272 nm; effect of conc.; CD and NMR also; (Kim) Dept. of Biology, Howard Hughes Medical Institute, Whitehead Institute of Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA 02142

**Stefanini, S., Cavallo, S., Wang, C.-Q., Tataseo, P., Vecchini, P., Giartosio, A., Chiancone, E. Thermal stability of horse spleen apoferritin and human recombinant H apoferritin. Arch. Biochem. Biophys. 325, 58-64 (1996)

Optima XL-A, sed. vel., S; native and reassociated horse spleen apoferritin and subunits; 20deg.C; CD and calorimetry also used; (Chiancone) CNR Center of Molecular Biology c/o Dept. of Biochemical Sciences "A. Rossi Farelli" Univ. La Sapianza, Piazzale A. Moro 5, 00185 Rome, Italy

**Tomschy, A., Fauser, C., Landwehr, R., Engel, J. Homophilic adhesion of E-cadherin occurs by a co-operative two-step interaction of N-terminal domains. EMBO J. 15, 3507-3514 (1996)

Optima XL-A, sed. equil., m, state of association; sed. vel., S; recombinant mouse E-cadherin and chimeric ECAD-COMP protein; An-60 Ti, 4.2, 6.8, 12 and 17 krpm (s.e.); 32, 48 and 56 krpm (s.v.); 230 and 278 nm; electron microscopy also used; (Engel) Abteilung fur Biophysikalische Chemie, Biozentrum, Universitat Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland

**Tziatzios, C., Schuck, P., Schubert, D., Tsiotis, G. The molar mass of an active photosystem I complex from the cyanobacterium Synechococcus PCC 7002. Z. Naturforsch., C: Biosci. 49, 220-222 (1994)

Optima XL-A, sed. equil., M(r), v-bar; Synechococcus photosystem I complex (protein-pigment complex); D(2)O/D(18)O method for v-bar; effect of three detergents; (Schubert) Institut fur Biophysik der J. W. Goethe-Universitat, Theodor-Stern, Kai 7, Hous 74, D-60590 Frankfurt am Main, Bundesrepublik Deutschland

**Ushiyama, S., Laue, T. M., Moore, K. L., Erickson, H. P., McEver, R. P. Structural and functional characterization of monomeric soluble P-selectin and comparison with membrane P-selectin. J. Biol. Chem. 268, 15229-15237 (1993)

Optima XL-A, sed. equil., M(r) in 6 M GuHCl & D(2)O; Optima XL-A, Model E with absorbance optics, sed. vel., S; Model E, interference optics, sed. equil., M(r) in detergent & D(2)O; recombinant membrane and soluble P-selectin and modified forms; 10-30 krpm (s.e.), 36-60 krpm (s.v.); 280 or 230 nm; (McEver) W. K. Warren Medical Research Institute, Univ. of Oklahoma Health Sciences Center, 825 N. E. 13th St., Oklahoma City, OK 73104

**Voelker, P. Measurement of the extinction coefficient of prostate specific antigen using interference and absorbance optics in the Optima XL-A analytical ultracentrifuge. Progress in Colloid & Polymer Science, Vol. 99, pp. 162-166. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-I (prototype), interference and absorbance optics, sed. vel., extinction coefficient; prostate-specific antigen; 8, then 4 krpm, synthetic boundary cell; interference optical system diagramed and described, 25deg.C; 280 nm; Beckman Instruments, Inc., 1050 Page Mill Rd., Palo Alto, CA 94304

**Waldburger, C. D., Sauer, R. T. Domains of Mnt repressor: roles in tetramer formation, protein stability, and operator DNA binding. Biochemistry 34, 13109-13116 (1995)

Optima XL-A, sed. equil., M(w), state of oligomerization; bacteriophage P22 Mnt repressor and fragments; 15, 20 and 30 krpm, 22deg.C, CD and PAGE also used; (Sauer) Dept. of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139

**Ward, L. D., Howlett, G. J., Discolo, G., Yasukawa, K., Hammacher, A., Moritz, R. L., Simpson, R. J. High affinity interleukin-6 receptor is a hexameric complex consisting of two molecules each of interleukin-6, interleukin-6 receptor, and gp-130. J. Biol. Chem. 269, 23286-23289 (1994)

Optima XL-A, sed. equil., M; recombinant human interleukin-6, its receptor and IL-6-receptor-gp-130 complex; 12-, 10-, 8- and 6-krpm; BIAcore & SEC also used; (Simpson) Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research, Post Office Royal Melbourne Hospital, Parksville, Victoria 3050, Australia

**Ward, L. D., Howlett, G. J., Hammacher, A., Weinstock, J., Yasukawa, K., Simpson, R. J., Winzor, D. J. Use of a biosensor with surface plasmon resonance detection for the determination of binding constants: measurement of interleukin-6 binding to the soluble interleukin-6 receptor. Biochemistry 34, 2901-2907 (1995)

Optima XL-A, sed. equil., M; recombinant interleukin and its receptor; 8 & 12 krpm 20deg.C, 230 nm; BIAcore used for binding constants; (Simpson) Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research, P.O., Royal Melbourne Hospital, Parkville, Victoria 3050, Australia

**Ward, L. D., Howlett, G. J., Moritz, R. L., Hammacher, A., Yasukawa, K., Simpson, R. J. Studies of cytokine-cytokine receptor interactions: influence of ligand dimerization. Techniques in Protein Chemistry, Vol. 6, pp. 417-425. Edited by J. W. Crabb. San Diego, Academic Press, 1995.

Optima XL-A, sed. equil., M; recombinant interleukins IL-6D and IL-6M; 12 krpm; BIAcore also used; state of association; Joint Protein Structure Laboratory, Ludwig Inst. for Cancer Research (Melbourne) and The Walter and Eliza Hall Inst. of Medical Research, Parkville, Vic., Australia

**Ward, L. D., Hammacher, A., Howlett, G. J., Matthews, J. M., Fabri, L., Moritz, R. L., Nice, E. C., Weinstock, J., Simpson, R. J. Influence of interleukin-6 (IL-6) dimerization on formation of the high affinity hexameric IL-6:receptor complex. J. Biol. Chem. 271, 20138-20144 (1996)

Optima XL-A, sed. equil., M(r); recombinant human interleukin-6 monomer, dimer and their receptor complexes; 8 and 12 krpm, 20deg.C; BIAcore also used; (Simpson) Joint Protein Structure Laboratory, Ludwig Inst. for Cancer Research, P.O. Box 2008, Royal Melbourne Hospital, Victoria, 3050, Australia

**Waxman, E., Laws, W. R., Laue, T. M., Nemerson, Y., Ross, J. B. A. Human factor VIIa and its complex with soluble tissue factor: evaluation of asymmetry and conformational dynamics by ultracentrifugation and fluorescence anisotropy decay methods. Biochemistry 32, 3005-3012 (1993)

Optima XL-A, sed. vel., f/f (sphere), S; Model E with interference optics, sed. equil., M(r); human blood coagulation factor VIIa and its soluble tissue factor complex; (Nemerson) Dept. of Biochemistry, Mount Sinai School of Medicine, New York, NY 10029

**Willard, D. H., Bodnar, W., Harris, C., Kiefer, L., Nichols, J. S., Blanchard, S., Hoffman, C., Moyer, M., Burkhart, W., Weiel, J., Luther, M. A., Wilkison, W. O., Rocque, W. J. Agouti structure and function: characterization of a potent alpha-melanocyte stimulating hormone receptor antagonist. Biochemistry 34, 12341-12346 (1995)

Optima XL-A, sed. equil., state of association; recombinant murine agouti and its C-terminal domain monomer-dimer; 15, 17, 20, 22.5 and 25 krpm, 220 nm, 4deg.C; CD and fluorescence also used; (Rocque) Dept. of Biochemistry, Glaxo Wellcome, Inc., Five Moore Drive, Research Triangle Park, NC 27709

**Williams, P. A., Ful^p, V., Leung, Y.-C., Chan, C., Moir, J. W. B., Howlett, G., Ferguson, S. J., Radford, S. E., Hajdu, J. Pseudospecific docking surfaces on electron transfer proteins as illustrated by pseudoazurin, cytochrome c(550) and cytochrome cd(1) nitrite reductase. Nature, Struct. Biol. 2, 975-982 (1995)

Optima XL-A, sed. equil., K(a), degree of oligomerization; recombinant oxidized and reduced pseudoazurin; 15 krpm, 450 or 290 nm, effect of pH, 20 or 30deg.C; X-ray diffraction also used; (Williams and Hajdu) Laboratory of Molecular Biophysics, Univ. of Oxford, South Parks Rd., Oxford OX1 3QU, UK

**Wilson, T. J., Maroudas, P., Howlett, G. J., Davidson, B. E. Ligand-induced self-association of the Escherichia coli regulatory protein TyrR. J. Mol. Biol. 238, 309-318 (1994)

Optima XL-A, sed. equil., m; sed. vel., S; effect of ligands ATP and tyrosine on E. coli regulatory protein TyrR self-association; An-60 Ti, 5 kg (s.e.), 125 kg (s.v.); Russell Grimwade School of Biochemistry, Univ. of Melbourne, Parkville, Victoria 3052, Australia

**Wu, L. C., Peng, Z., Kim, P. S. Bipartite structure of the alpha-lactalbumin molten globule. Nature, Struct. Biol. 2, 281-286 (1995)

Optima XL-A, sed. equil., state of association; recombinant alpha-lactalbumin alpha- and beta-variant monomers; An-60 Ti, 23 & 27 krpm, 4deg.C; CD also; Howard Hughes Medical Institute, Whiehead Institute for Biomedical Research, Dept. of Biology, MIT, Nine Cambridge Center, Cambridge, MA

**Wu, L. C., Schulman, B. A., Peng, Z., Kim, P. S. Disulfide determinants of calcium-induced packing in alpha-lactalbumin. Biochemistry 35, 859-863 (1996)

Optima XL-A, sed. equil., effect of CaCl(2) on state of aggregation; recombinant alpha-lactalbumin variants; CD also used; (Kim) Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Dept. of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142

**Ybarra, J., Horowitz, P. M. Inactive GroEL monomers can be isolated and reassembled to functional tetradecamers that contain few bound peptides. J. Biol. Chem. 270, 22962-22967 (1995)

Optima XL-A, sed. vel., state of association; chaperonin EL monomers; fluorescence and PAGE also used; (Horowitz) Dept. of Biochemistry, 7703 Floyd Curl Dr., San Antonio, TX 78284-7760

**Yoo, S. H., Lewis, M. S. Effects of pH and Ca(2+) on heterodimer and heterotetramer formation by chromogranin A and chromogranin B. J. Biol. Chem. 271, 17041-17046 (1996)

Optima XL-A, sed. equil., delta C, delta G, delta H, T delta S; beef adrenal chromogranin A and chromogranin B heterodimer and heterotetramer formation; 8 krpm, 2, 5, 8, 11, 14, 17, and 20deg.C; 280 nm, effect of pH and temperature; Laboratory of Neurochemistry, 5 Research Court, 2A37 NIDCD, Natl. Inst. of Health, Bethesda, MD 20892-3320

**Yu, F.-X., Lin, S.-C., Morrison-Bogorad, M., Atkinson, M. A. L., Yin. H. L. Thymosin beta 10 and thymosin beta 4 are both actin monomer sequestering proteins. J. Biol. Chem. 268, 502-509 (1993)

Optima XL-A, sed. equil., M(w); recombinant thymosin beta 4 monomer-dimer; An-60-Ti, 40 krpm, 277 K; (Yu) Dept. of Physiology, Univ. of Texas Southwestern Medical Center, Dallas, TX 75235.

**Zioncheck, T. F., Richardson, L., Liu, J., Chang, L., King, K. L., Bennett, G. L., Fugedi, P., Chamow, S. M., Schwall, R. H., Stack, R. J. Sulfated oligosaccharides promote hepatocyte growth factor association and govern its mitogenic activity. J. Biol. Chem. 270, 16871-16878 (1995)

Optima XL-A, sed. equil., m, state of association; recombinant human hepatocyte growth factor in presence of sulfated maltoheptaose; 10 and 15 krpm, 20deg.C; SEC also used; Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 95247

**Zondlo, J., Fisher, K. E., Lin, Z., Ducote, K. R., Eisenstein, E. Monomer-heptamer equilibrium of the Escherichia coli chaperonin GroES. Biochemistry 34, 10334-10339 (1995)

Optima XL-A, sed. equil., association constants; recombinant Escherichia coli chaperonin GroES monomer-heptamer; An-55, 28-32 krpm, 275 nm, 25deg.C; fluorescence and light scattering also used; (Eisenstein) Center for Advanced Research in Biotechnology, Univ. of Maryland Biotechnology Institute, 9600 Gudelsky Dr., Rockville, MD 20850, and Dept. of Chemistry and Biochemistry, Univ. of Maryland Baltimore County, Baltimore, MD 21228

Synthetic Polymers

**Kehrhahn, J.-H., Lechner, M. D., Machtle, W. Analytical ultracentrifugation with the new Optima XL-A and its digital u.v./vis. detector: determination of molar mass distribution of polymers from sedimentation velocity. Polymer 34, 2447-2452 (1993)

Optima XL-A, sed. vel., m, mol. mass distribution (MMD); several polystyrenes and sodium polystyrene sulfonate; contains both favorable comments and some criticisms; used own software, which is available on requests; (Lechner) Physikalische Chemie, Universitat Osnabruck, Barbarastrsse 7, D-4500 Osnabruck, Germany

**Lechner, M. D., Machtle, W. Sedimentation equilibrium measurements with the new analytical ultracentrifuge Optima XL-A and its digital ultraviolet/visible detector. Makromol. Chem., Rapid Commun. 13, 555-563 (1992)

Optima XL-A, sed. equil., M(n), M(w), M(z); polystyrene and polystyrene sulfonate; also specific decadic absorption coefficient detd; 260 nm; (Lechner) Physikalische Chemie, Universitat Osnabruck, Germany

**Muller, H. G., Herrmann, F. Simultaneous determination of particle and density distributions of dispersions by analytical ultracentrifugation. Progress in Colloid & Polymer Science, Vol. 99, pp. 114-119. Edited by J. Behlke. Darmstadt, Steinkopff Verlag, 1995.

Optima XL-A with modified optics and Heraeus-Christ 8-hole rotor, sed. vel., rho and S distributions; polystyrene and SBR latex mixtures; D(2)O and H(2)O; Bayer AG, Central Research Div., ZF-TPP 3, Geb. E-41, 51368 Leverkusen, Germany

Viruses

**Barge, A., Gagnon, J., Chaffotte, A., Timmins, P., Langowski, J., Ruigrok, R. W. H., Gaudin, Y. Rod-like shape of vesicular stomatitis virus matrix protein. Virology 219, 465-470 (1996)

Optima XL-A (inferred), sed. vel., S; vesicular stomatitis virus M protein; 60 krpm; effect of concentration; light scattering and small-angle neutron scattering; (Gaudin) Laboratoire de Genetique des virus, CNRS, 91198 Gif sur Yvette Cedex, France

**Blacklow, S. C., Lu, M., Kim, P. S. A trimeric subdomain of the simian immunodeficiency virus envelope glycoprotein. Biochemistry 34, 14955-14962 (1995)

Optima XL-A, sed. equil., m, state of oligomerization; recombinant SIV envelope glycoprotein domain peptides and their trimeric complex; An-60 Ti, 13-20 krpm, 20deg.C, CD also used; (Kim) Howard Hughes Medical Institute, Whitehead Institute for Biomedical Research, Dept. of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142

**Burz, D. S., Ackers, G. K. Cooperativity mutants of bacteriophage lambda cI repressor: temperature dependence of self-assembly. Biochemistry 35, 3341-3350 (1996)

Optima, XL-A, sed. equil., delta G, M, state of oligomerization; recombinant bacteriophage lambda cI repressor and mutants; An-60 Ti, 10-45 krpm, 280 nm, 5-40deg.C; effect of speed and concentration; FC43 used; (Ackers) Dept. of Biochemistry and Molecular Biophysics, Washington Univ. School of Medicine, St. Louis, MO 63110

**Cole, J. L., Gehman, J. D., Shafer, J. A., Kuo, L. C. Solution oligomerization of the rev protein of HIV-1: implications for function. Biochemistry 32, 11769-11775 (1993)

Optima XL-A, sed. equil., K(a); recombinant HIV-1 rev RNA-binding protein; 10-26 krpm; Dept. of Biological Chemistry, Merck Research Laboratories, West Point, PA 19486

**Gaudin, Y., Barge, A., Ebel, C., Ruigrok, R. W. H. Aggregation of VSV M protein is reversible and mediated by nucleation sites: implications for viral assembly. Virology 206, 28-37 (1995)

Optima XL-A, sed. vel., S; vesicular stomatitis protein M and aggregates; An-60 Ti, 3 & 24 krpm; effect of salt conc.; 280 nm; (Gaudin) Laboratoire de genetique des virus du CNRS, 91198 Gif sur Yvette Cedex, France

**Kosukegawa, A., Arisaka, F., Takayama, M., Yajima, H., Kaidow, A., Handa, H. Purification and characterization of virus-like particles and pentamers produced by the expression of SV40 capsid proteins in insect cells. Biochim. Biophys. Acta 1290, 37-45 (1996)

Optima XL-A, sed. equil., m; sed. vel., S; recombinant baculovirus-expressed SV40 virus-like particles and capsid protein pentamers; An-60 Ti, 3500 rpm (s.e.), 10, 15, or 40 krpm (s.v.), 20deg.C, 280 nm; electron microscopy also used; (Handa) Faculty of Bioscience and Biotechnology, Tokyo Inst. of Technology, 4259 Nagatsuta-cho, Midori-ku Yokohama 226, Japan

**Rabenstein, M., Shin, Y.-K. A peptide from the heptad repeat of human immunodeficiency virus gp41 shows both membrane binding and coiled-coil formation. Biochemistry 34, 13390-13397 (1995)

Optima XL-A, sed, equil., m, state of oligomerization; HIV envelope glycoprotein coiled-coil peptide; 40 krpm, effect of concentration; CD and EPR also used; (Shin) Dept. of Chemistry, Univ. of California, Berkeley, CA 94720

**Senear, D. F., Laue, T. M., Ross, J. B. A., Waxman, E., Eaton, S., Rusinova, E. The primary self-assembly reaction of bacteriophage lambda cI repressor dimers is to octamer. Biochemistry 32, 6179-6189 (1993)

Optima XL-A, sed. equil., M(r); sed. vel., g (s), S; Model E, interference optics, sed. equil., M(r); native and 5-OHTrp-substituted repressor dimers and octamers; effect of speed, salt, and concentration; 10-40 krpm (s.e.), 60 krpm, (s.v.); (Senear) Dept. of Molecular Biology and Biochemistry, Univ. of California, Irvine, California 92717

**Shearwin, K. E., Egan, J. B. Purification and self-association equilibria of the lysis-lysogeny switch proteins of coliphage 186. J. Biol. Chem. 271, 11525-11531 (1996)

Optima XL-A, sed. equil., M, state of association; recombinant bacteriophage 186 switch proteins; An-60 Ti, 12, 16 and 24 krpm; 230 or 280 nm, 5deg.C, PAGE also used; effect of speed and concentration; (Egan) Dept. of Biochemistry, Univ. of Adelaide, Adelaide, Australia 5005

**Shire, S. J. Analytical ultracentrifugation and its use in biotechnology. Modern Analytical Ultracentrifugation, pp. 261-297. Edited by T. M. Schuster and T. M. Laue. Boston, Birkhauser, 1994.

Optima XL-A, sed. equil., M; recombinant HIV-1 envelope glycoprotein, recombinant apolipoprotein A, and human tumor necrosis factor type 1 receptor and its TNF-alpha complex; 5, 10 or 15 krpm; Dept. of Pharmaceutical R&D, Genentech, Inc., 460 Point San Bruno Blvd., South San Francisco, CA 94080

**Shugars, D. C., Wild, C. T., Greenwell, T. K., Matthews, T. J. Biophysical characterization of recombinant proteins expressing the leucine zipper-like domain of the human immunodeficiency virus type 1 transmembrane protein gp41. J. Virol. 70, 2982-2991 (1996)

Optima XL-A, sed. equil., K(a), M, state of oligomerization; sed. vel., S; recombinant HIV-1 protein gp(41) leucine zipper-like domain; An-60 Ti, 7-12 krpm (s.e.), 24 krpm (s.v.), 220 or 280 nm, 20 or 25deg.C; light scattering and SEC also used; (Matthews) Dept. of Surgery, Duke Univ. Med. Ctr., Durham, NC 27710

**Stafford, W. F., Liu, S., Prevelige, P. E. New high sensitivity sedimentation methods: application to the analysis of the assembly of bacteriophage P22. Techniques in Protein Chemistry, Vol. 6, pp. 427-434. Edited by J. W. Crabb. San Diego, Academic Press, 1995.

Optima XL-A with both absorption and video-based on-line interference optics, g(s*) vs. s*; bacteriophage P22 coat protein-bisANS dye interaction; Analytical Centrifugation Research Laboratory, Boston Biomedical Research Institute, Boston, MA 02114

**Tuma, R., Bamford, J. H. K., Bamford, D. H., Russell, M. P., Thomas, G. J., Jr. Structure, interactions and dynamics of PRD1 virus. I. Coupling of subunit folding and capsid assembly. J. Mol. Biol. 257, 87-101 (1996)

Optima XL-A, sed. equil., m; state of association; bacteriophage PRD1 P3 shells; An-60, 10 krpm; 280, 310 and 330 nm, 10deg.C; Raman spectroscopy and electron microscopy also used; effect of concentration; (Thomas) Div. of Cell Biology and Biophysics, School of Biological Sciences, Univ. of Missouri-Kansas City, Kansas City, MO 64110

**Wingfield, P. T., Stahl, S. J., Williams, R. W., Steven, A. C. Hepatitis core antigen produced in Escherichia coli: subunit composition, conformational analysis, and in vitro capsid assembly. Biochemistry 34, 4919-4932 (1995)

Optima XL-A, sed. equil., m, sed. vel., S; recombinant hepatitis B virus capsid antigens; An-60 Ti, 1800-2800 rpm (s.e.), 12-45 krpm (s.v.), 20deg.C, CD, fluorescence, Raman spectroscopy and EM also used, Protein Expression Laboratory, National Institutes of Health, Bethesda, MD 20892-2775

**Zlotnick, A., Cheng, N., Conway, J. F., Booy, F. P., Steven, A. C., Stahl, S. J., Wingfield, P. T. Dimorphism of hepatitis B virus capsids is strongly influenced by the C-terminus of the capsid protein. Biochemistry 35, 7412-7421 (1996)

Optima XL-A, sed. vel., g*(s), state of oligomerization; hepatitis B virus capsids; An-60 Ti, 20 krpm, 20deg.C; electron microscopy and sucrose gradient centrifugation also used and data compared; (Steven) Bldg. 6, Rm. 425, NIH, Bethesda, MD 20892-2855