Current Opin ion in STRUCTUNAE

BIOLOGY Volume 1 Number 1 February 1991

Wayne Hendrickson and Editorial Aaron Klug

Thomas E. Creighton and Peter S. Kim

Thomas E. Creighton

Brian W. Matthews

Christopher M. Dobson

C. Robert Matthews

Franz X. Schmid

Jo@l Janin

Wolfram Bode and Robert Huber

Cyrus Chothia

Folding and binding edited by Thomas E. Creishton and Peter S. Kim

Folding and binding:editorial overview

Stability of folded conformations

Mutational analysis of protein stability

Characterization of protein folding intermediates

The mechanism of protein folding

Catalysis and assistance of protein folding

Protein-protein interactions and assembly

Ligand binding: proteinase-protein inhibitor interactions

Antigen recognition

5

17

22

28

36

42

45

53

Paul B. Sigler

Robert Kaptein

Tom K. Kerppola and Tom Curran

Richard G. Brennan

Simon E.V. Phillips

Mary-Ann Bjomsti

John M. Rosenberg

Andrew A. Travers

Protein-nucleic acid interactions edited by Paul B. $igler

Protein-nucleic acid interactions: editorial overview

Zinc fingers

Transcription factor interactions: basics on zippers

61

63

71

Interactions of the helix-turn-helix binding domain 80

Specific ~-sheet interactions 89

DNA topoisomerases 99

Structure and function of restriction endonucleases 104

DNA bending and kinking - - sequence dependence and function 114

Continued

iii

iv

Catherine M. Joyce

Wolfram Saenger

Thomas A. Steitz

Can DNA polymerase I (Klenow fragment) serve as a model for other polymerases?

Structure and catalytic function of nucleases

Aminoacyl-tRNA synthetases: structural aspects of evolution and tRNA recognition

Current world literature

Contents

Folding and binding

Protein-nucleic acid interactions

Reports of structures

Index to subjects

List of journals scanned

Subscription information

123

130

139

145

145

156

167

Volume 1 Number 2 April 1991

Barry Honig

Kim A. Sharp

Donald Bashford

David S. Cafiso

Herman J.C. Berendsen

J. Andrew McCammon

Wendy D. Cornell, Allison E. Howard and

Peter Kollman

Stanley K. Burr, Charles W. Hutchins and

Jonathan Greer

Mark B, Swindells and Janet M. Thornton

Michael Levitt

Stephen C. Harrison and David J. DeRosier

Peter M. Colman

Theory and simulation edited by Barry Honig

Theory and simulation: editorial overview

The hydrophobic effect

Electrostatic effects in biological molecules

Lipid bilayers: membrane-protein electrostatic interactions

Molecular dynamics studies of proteins and nucleic acids

Free energy from simulations

Molecular mechanical potential functions and their application to study molecular systems

Predicting receptor-ligand interactions

Modelling by homology

Protein folding

Macromolecular assemblages edited by Stephen C. Harrison and David I. DeRosier

Macromolecular assemblages: editorial overview

Antigen-antigen receptor interactions

169

171

175

185

191

196

201

213

219

224

231

232

Continued

William C. Earnshaw

Jonathan Widom

Sandra L. Wolin and Peter Walter

Peter B. Moore

James A. Spudich and Hans M. Warrick

Kenneth C. Holmes and Wolfgang Kabsch

Anthony Bretscher

Stephen C. Harrison

Large scale chromosome structure and organization

Nucleosomes and chromatin

Small ribonucleoproteins

Ribosomes

A tale of two motors

Muscle proteins: actin

Molecular aspects of microfilament structure and assembly

Viruses

237

245

251

258

264

270

281

288

Current world literature

Theory and simulation

Macromolecular assemblages

Reports of structures

Index of subjects

List of journals scanned and subscription information

297

305

317

Thomas L. Blundell and Russell F. Doolittle

William R. Pearson

William R. Taylor and David T. Jones

Mark S. Johnson

Malcolm J. McGregor and Fred E. Cohen

L,~szl6 Patthy

Milton H. Saier Jr and Jonathan Reizer

Steven K. Hanks

Kei-ichi Kuma, Naoyuki Iwabe and

Takashi Miyata

Anthony R. Keflavage

Volume 1 Number 3 June 1991

Sequences and topology edited by Thomas Blundell and Russell Dooliltle

Sequences and topology: editorial overview

Identifying distantly related protein sequences

Templates, consensus patterns and motifs

Comparisons of protein structures

Analysis of conformational tendencies in proteins

Modular exchange principles in proteins

Families and superfamilies of transport proteins common to prokaryotes and eukaryotes

Eukaryotic protein kinases

The immunoglobulin family

G-protein-coupled receptor family

319

321

327

334

345

351

362

369

384

394

Continued

vi

Paul I. Hagerman and Richard E. Dickerson

Brian Wimberly, Gabriele Varani and

Ignacio Tinoco Jr

Dino Moras

Kenneth J. Breslauer

Helen M. Berman

Thomas D. Tullius

Dipankar Sen and Walter Gilbert

Dara E. Gilbert and Juli Feigon

Zippora Shakked

David E. Wemmer

Olke C. Uhlenbeck

Julia P. Cooper and Paul J. Hagerman

Nucleic acids edited by Richard Dickerson and Paul Hagerman

Nucleic acids: editorial overview

Structural determinants of RNA function

403

405

Transfer RNA 410

A thermodynamic perspective of DNA bending 416

Hydration of DNA 423

The use of chemical probes to analyse DNA and RNA structures 428

The structure of telomeric DNA: DNA quadriplex formation 435

Structural analysis of drug-DNA interactions 439

The influence of the environment on DNA structures 446 determined by X-ray crystallography

The applicability of NMR methods to solution structure of 452 nucleic acids

Catalytic RNAs 459

Structure of branched DNA molecules in solution 464

Current world literature

Contents

Sequences and topology

Nucleic acids

Reports of structures

Index of subjects

List of journals scanned and subscription information

469

469

483

497

Volume 1 Number 4 August 1991

Vittorio Luzzati and Donald M. Small

Paolo Mariani

Fran(;oise Reiss-Husson

John P. Kane

Lipids edited by Vittorio Luzzati and Donald Small

Lipids: editorial overview

The cubic phases

Lipid-protein interactions in reconstituted model systems

Plasma lipoproteins and their receptors

499

501

5O6

510

Continued

Alfred H. Merrill Jr and Dennis C. Liotta

Michael A. J. Ferguson

Lipids as hormones and second messengers

Lipid anchors on membrane proteins

516

522

vii

Werner KOhlbrandt

J6rg Tittor

Tilman Schirmer and Jurg P. Rosenbusch

Bruce A. Diner, Peter J. Nixon and

Joseph W. Farchaus

David L. Stokes

Roderick A. Capaldi

F. Anne Stephenson

Paul A. Hargrave

Yosef Yarden and Zvi Kelman

Peter J.F. Henderson

Membrane proteins edited by Werner K~hlbrandt

Membrane proteins: editorial overview

A new view of an old pump: bacteriorhodopsin

Prokaryotic and eukaryotic porins

Site-directed mutagenesis of photosynthetic reaction centers

P-type ion pumps: structure determination may soon catch up with structure predictions

Structural features of the mitochondrial electron-transfer chain

Ion channels

Seven-helix receptors

Transmembrane signalling receptors for cytokines and growth factors

Sugar transport proteins

531

534

539

546

555

562

569

575

582

590

F. Raymond Salemme and James A. Wells

Mark J. Zoller

William M. Atkins and Stephen G. Sligar

Charles Wilson and David A. Agard

Cristina T. Lewis and Donald Hilvert

Chris Sander

David A. Tirrell, Maurille J. Fournier and

Thomas L. Mason

Roger D. Kornberg and Seth A. Darst

Harden M. McConnell, Peter Rice, Garrett H. Wada,

John C. Owicki and J. Wallace Parce

Nadrian C. Seeman

Engineering and design edited by F. Raymond Salemme and James Wells

Engineering and design: editorial overview

New molecular biology methods for protein engineering

Protein engineering for studying enzyme catalytic mechanism

Engineering substrate specificity

Engineered antibodies

De novo design of proteins

Protein engineering for materials applications

Two-dimensional crystals of proteins on lipid layers

The microphysiometer biosensor

DNA structural engineering using immobile junctions

603

605

611

617

624

630

638

642

647

653

Continued

. . o V I I I

Current world literature

Contents

Lipids

Membrane proteins

Engineering and design

Bibliography of atomic structures

Index of subjects

List of journals scanned and subscription information

663

663

672

695

707

Volume 1 Number 5 October 1991

Raymond A. Dwek and Florante A. Quiocho

John W. Brady

Jeremy P. Carver

Karl-Heinz Jung and Richard R. Schmidt

Nand K. Vyas

Halina Lis and Nathan Sharon

Raj B. Parekh

Harry Schachter

Ten Feizi

Philip R. Evans and Christopher T. Walsh

Philip R. Evans

Richard Wolfenden and Anna Radzicka

JoAnne Stubbe

Emil F. Pai

John B.C. Findlay

Paul Schimmel

Alan Hall

Carbohydrates and glycobiology edited by Raymond A. Dwek and Florante A. Quiocho

Carbohydrates and glycobiology: editorial overview

Theoretical studies of oligosaccharide structure and conformational dynamics

Experimental structure determination of oligosaccharides

Structure and synthesis of biologically active glycopeptides and glycolipids

Atomic features of protein-carbohydrate interactions

Lectin--carbohydrate interactions

Effects of glycosylation on protein function

Enzymes associated with glycosylation

Cell-cell adhesion and membrane glycosylation

Catalysis and regulation edited by Philip R. Evans and Chrislopher T. Walsh

Catalysis and regulation: editorial overview

Structural aspects of allostery

Transition-state analogues

Dinuclear non-heme iron centers: structure and function

Variations on a theme: the family of FAD-dependent NAD(P)H-(disulphide)-oxidoreductases

Structure and function in membrane transport systems

Mutant enzymes and dissected tRNAs that elucidate motifs for protein-RNA recognition

GTP-binding proteins

709

711

716

721

732

741

750

755

766

771

773

780

788

796

8O4

811

817

Continued

Joseph J. Villafranca

Robert M. Stroud

Michael H. Gelb, Otto Berg and

Mahendra K. Jain

Metal-assisted catalysis

Mechanisms of biological control by phosphorylation

Quantitative and structural analysis of inhibitors of phospholipase A 2

Current world literature

Contents

Carbohydrates and glycobiology

Catalysis and regulation

Bibliography of atomic structures

Index of subjects

List of journals scanned and subscription information

821

826

836

845

845

856

873

ix

Volume 1 Number 6 December 1991

Wim G.J. Hol

Donald LD. Caspar and John Badger

Georg E. Schulz

Jacques Vervoort

Elinor T. Adman

Natalie C.J. Strynadka and Michael N.G. James

Austen F. Ri&gs

Florante A. Quiocho

}ens Brange, Guy G. Dodson and

Bing Xiao

Emil F. Pal

Osnat Herzberg and John Moult

F. Scott Mathews

Judith P. Klinman

Robert L. Dorit and Walter Gilbert

Carl-lvar Br~nd~n

Proteins edited by Wim G.J. Hol

Proteins: editorial overview

Plasticity of crystalline proteins

Domain motions in proteins

Electron-transferring proteins

Structure and function of copper-containing proteins

Towards an understanding of the effects of calcium on protein structure and function

Hemoglobin

Atomic structures and function of periplasmic receptors for active transport and chemotaxis

Designing insulin for diabetes therapy by protein engineering

875

877

883

889

895

9O5

915

922

934

p21 and other guanine-nucleotide-interacting proteins

Penicillin-binding and degrading proteins

941

946

New flavoenzymes

Surprises among quinoproteins

The limited universe of exons

954

968

973

The TIM barrel-- the most frequently occurring folding motif in proteins

978

Continued

William F. DeGrado, Daniel P. Raleigh and

Tracey Handel

Keith Moffat and Gerhard Wagner

Ramachandran Murali and Roger M. Burnett

Janet L. Smith

Keith D. Watenpaugh

Axel T. Br6nger

Friedrich Zemlin

Ad Bax

Jeffrey C. Hoch, Christina Redfield and

Alan S. Stern

Thomas L. James

Franklyn G. Prendergast

Aaron Lewis

De novo protein design! what are we teaming?

Biophysical methods edited by Keith Moffat and Gerhard Wagner

Biophysical methods: editorial overview

X-ray crystallography of very large unit cells

Determination of three-dimensional structure by multiwavelength anomalous diffraction

Macromolecular crystallography at cryogenic temperatures

Crystallographic phasing and refinement of macromolecules

Recent developments in electron crystallography of protein crystals

Experimental NMR techniques for studies of biopolymers

Computer-aided analysis of protein NMR spectra

984

995

997

1002

1012

1016

1023

1030

1036

Relaxation matrix analysis of two-dimensional nuclear Overhauser 1042 effect spectra

Time-resolved fluorescence techniques: methods and applications 1054 in biology

Three-dimensional subwavelength resolution with light 1060

Current world literature

Contents 1065

Proteins 1065

Biophysical methods 1090

Bibliography of atomic structures 1099

List of journals scanned and subscription information

A complete author and subject index to volume 1 appears at the end of this issue

Cumulative index to authors

Volume 1 1991

Adman, ET, 895 Agard, DA, 617 Atkins, WM, 611

Badger, J, 877 Bashford, D, 175 Bax, A, 1030 Berendsen, HJC, 191 Berg, O, 836 Berman, HM, 423 Blundell, TL, 319 Brand,n, C-I, 978 Br6nger, AT, 1016 Brady, JW, 711 Brange, J, 934 Breslauer, KJ, 416 Bretscher, A, 281 Burnett, RM, 997 Burt, SK, 213

Cafiso, DS, 185 Capaldi, RA, 562 Carver, JP, 716 Caspar, DLD, 877 Cohen, FE, 345 Colman, PM, 232 Cooper, JP, 464 Cornell, WD, 201

Darst, SA, 642 DeGrado, WF, 984 DeRosier, DJ, 231 Dickerson, RE, 405 Diner, BA, 546 Dodson, GG, 934 Doolittle, RF, 319 Dorit, RL, 973 Dwek, RA, 709

Earnshaw, WC, 237 Evans, PR, 771, 773

Farchaus, JW, 546 Feigon, J, 439 Feizi, T, 766 Ferguson, MA, 522 Findlay, JBC, 804 Fournier, MJ, 638

Gelb, MH, 836 Gilbert, DE, 439 Gilbert, W, 435, 973 Greer, J, 213

Hagerman, PJ, 403, 464 Hall, A, 817 Handel, T, 984

Hanks, SK, 369 Hargrave, PA, 575 Harrison, SC, 231, 288 Henderson, PJF, 590 Herzberg, O, 946 Hilvert, D, 624 Hoch, JC, 1036 Holmes, KC, 270 Hol, WGJ, 875 Honig, B, 169 Howard, AE, 201 Hutchins, CW, 213

Iwabe, N, 384

Jain, MK, 836 James, MNG, 905 James, TL, 1042 Johnson, MS, 334 Jones, DT, 327 Joyce, CM, 123 Jung, K-H, 721

KOhlbrandt, W, 531 Kabsch, W, 270 Kane, JP, 510 Kelman, Z, 582 Kerlavage, AR, 394 Klinman, JP, 968 Kollman, P, 201 Kornber& RD, 642 Kuma, K, 384

Levitt, M, 224 Lewis, A, 1060 Lewis, CT, 624 Liotta, DC, 516 Lis, H, 741 Luzzati, V, 499

Mariani, P, 501 Mason, TL, 638 Mathews, FS, 954 McCammon, JA, 196 McConnell, HM, 647 McGregor, MJ, 345 Merrill, AH, Jr, 516 Miyata, T, 384 Moffat, K, 995 Moore, PB, 258 Moras, D, 410 Moult, J, 946 Murali, R, 997

Nixon, PJ, 546

Owicki, JC, 647

Pai, EF, 796, 941

Parce, JW, 647 Parekh, RB, 750 Patthy, L, 351 Pearson, WR, 321 Prendergast, FG, 1054

Quiocho, FA, 709, 922

Radzicka, A, 780 Raleigh, DP, 984 Redfield, C, 1036 Reiss-Husson, F, 506 Reizer, J, 362 Rice, P, 647 Riggs, AF, 915 Rosenbusch, JP, 539

Saenger, W, 130 Saier, MH, Jr, 362 Salemme, FR, 603 Sander, C, 630 Schachter, H, 755 Schimmel, P, 811 Schirmer, 1", 539 Schmidt, RR, 721 Schulz, GE, 883 Seeman, NC, 653 Sen, D, 435 Shakked, Z, 446 Sharon, N, 741 Sharp, KA, 171 Sligar, SG, 611 Small, DM, 499 Smith, JL, 1002 Spudich, JA, 264 Steitz, TA, 139 Stephenson, FA, 569 Stern, AS, 1036 Stokes, DL, 555 Stroud, RM, 826 Strynadka, NCJ, 905 Stubbe, JA, 788 Swindells, MB, 219

Taylor, WR, 327 Thornton, JM, 219 Tinoco, I, Jr, 405 Tirrell, DA, 638 Tittor, J, 534 Tullius, TD, 428

Uhlenbeck, OC, 459

Varani, G, 405 Vervoort, J, 889 Villafranca, J J, 821 Vyas, NK, 732

Wada, GH, 647

© Current Biology Ud ISSN 0959-440X xi

xii

Wagner, C;, 995 Walsh, CT, 771 Walter, P, 251 Warrick HM, 264 Watenpaugh, KD, 1012 Wells, JA, 603

Wemmer, DE, 452 Widom, J, 245 Wilson, C, 617 Wimberly, B, 405 Wolfenden, R, 780 Wolin, SL, 251

Xiao, B, 934

Yarden, Y, 582

Zemlin, F, 1023 Zoller, MJ, 605

Cumulative index to subjects Volume 1 1991

A-factor export protein, 366 ABC transporters, 590 ABL subfamily, 379 ABO system, 759 ABP, 281, 282 Absorption spectrum, retinal, 577 Acceptor, of tRNA, 137, 813 Acceptor~elix subdomain, 814 Acetyl-pepstatin, 885 Acetylation, of histones, 245 Acetylcholine receptor

muscarinic, 575, 648 nicotinic, 569, 1026

Acetylcholinesterase, 523, 525 Acholeplasma laidlawii, 721-722 Achromobacter cycloclastes, nitrate reductase, 900 Acriflavine, 593 Actin

ATP hydrolysis, 273 binding sites, 274, 281 domain structure, 271 electron microscopy, 278 filaments, 264, 281-284

atomic model, 276-277 disordered, 277 structure, 274

monomer and polymer, 270, 271 organization into bundles, 281 ribbon hypothesis, 277 stability, 270 structure and function, 270-278, 281 X-ray studies, 278

Actin-DNAase complex, 278, 281 Actin-myosin complex, 265 Actin-profilin complex, 271,277 alpha-Actinin, 281, 282 Actinomyces spp., 745 Activation

free energy, 196 of lipase, 884

Active sites of glutathione reductase, 958 of isocitrate dehydrogenase, 829, 831, 833 of Klenow fragment, 123, 131-132 of beta-lactamases, 948 of lipoamide dehydrogenase, 958 of mercuric ion reductase, 799, 959 of phospholipase A2, 840, 841 of protein disulfide isomerase, 36 of proteinase inhibitor, 46 of proteinases, 4, 46, 49 of ribonuclease, 132, 133 of RNA synthetase, 138 of serine proteases, 323 of trypanothione reductase, 958

Active transport systems, 366, 922-931 Acyl coenzyme A dehydrogenase, 954, 955 Acyl coenzyme A reductase, 960 Acylation, of beta-lactamases, 949 Adenosine deaminase, 781,821-822, 978, 981 Adenoviruses, 292, 998 Adenylate cyclase, 363, 366, 818 Adenylate kinase

activation, 906 complex with substrate, 943 conformational changes, 884-886

Adhesion cell-cell, 766-769 inhibitors, 746 of pathogens, 746

Adhesion proteins, 640, 745 ADP~actin, 270, 271 ADP/ATP carrier, mitochondial, 506, 507 ADR1 protein, yeast, 63-64 Adrenergic receptor, 396 Adriamycin, 441 Aerolysin, 539 Affinity potential, 192 Affinity selection, 621 Aggregation

of proteins, 4, 32, 39 of synthetic peptides, 987-988

Aida, 634-635 ALADDIN, 214 Alamethicin, 186-187 Alanine tRNA synthetase, 813 Alanine-scanning mutagenesis, 606 Alcaligenes denitrificans, azurin, 897 Alcaligenes faecalis, nitrite reductase, 900 Alcohol dehydrogenase, 618 Aldophosphamide, 727 Algebra, linear, in NMR analysis, 1044, 1046 Algorithms

dynamic programming, 337 for image processing, 1037 for metalloprotein engineering, 633 for molecular modelling, 219, 220 multiple-alignment, 324, 328 for NMR studies, 1036-1039 optimization, in crystallography, 1017 pattern search, 899 for rigid-body superposition, 336 search, selectivity vs. sensitivity, 321 for sequence-symmetry minimization, 653-655, 656 simulated annealing, 1017 for structural analysis, 346 for structure refinement, 1018 for substrate specificity, 619 Taylor series, 1045 for tRNA motif identification, 412

Alignments

P © Current Biology Ltd ISSN 0959-440X xiii

xiv Index to subjects

consensus, 327 multiple, 323, 328 pairwise, 323, 328 sequence-based, 339 tree-based, 327

ALISON, software, 1038 Alkyl ethers, force fields, 204 AIIosteric effects

in hemoglobin, 915 in phosphorylation, 826, 828, 834 structural aspects, 773-778

Alpha4, synthetic protein, 988 Alpha-helix see also helix, 338, 348

antiparallel, 988 in bacteriorhodopsin, 534, 1024 barrel, 71, 104 bundle, 25, 71, 104 dipole, 18 in DNA contact surface, 75-76 formation, 25, 29 in glucocorticoid receptor, 66 in light-harvesting complex, 1025 in praying mantis ootheca protein, 1025 propensity, 19 protected amides in, 29 in reaction centres, 506 stability, 986 in zinc-finger peptides, 64-65

Alpha/beta barrel see also TIM barrel, 328, 339, 348, 981,980, 989

Alpha/beta structure, of binding proteins, 924 Alzheimer's disease, 565 Amalgam, 387 Amaranthus hybridus, 549 AMBER (assisted model building with energy refinement), 193, 203, 204, 206, 718 Amicyanin, 898 Amide

groups, interactions with nucleic acid, 89 hydrogen bond, 198 hydrogens, 23-24, 29

Amine oxidases, 902, 968, 969-970 Amino acid decarboxylases, 968 Amino acid residues

buried, 347 in de novo proteins, 630-631 functional, identification, 606 in heme pocket, 915, 917-918 in native and mutant insulin, 935-939

Amino acid sequence of DNA polymerases, 125-126 of DNA topoisomerases, 99 of DNA-binding proteins, 71 of gag gene products, 65-66 of immunoglobulins, 53, 55 in leucine zipper, 74 of P-type pumps, 555 of repressor proteins, 84 of RNA synthetases, 137, 139

of T cell receptors, 57 of transport proteins, 590, 593 of zinc fingers, 64

Amino acid transporter, AroP, 365 Amino acids

active transport, 923 hydration, 341, 345 interchange, 341 non-standard, 347, 989-990 recognition by tRNA, 137

Aminoacyl-tRNA synthetases see RNA synthetases Aminoacylaction, of minihelices, 813-814 Ammonium sulphate, as cosolvent, 10 AMP deaminase, 784 Amphiphilicity, of designed proteins, 991 Amsacrine, 101 Amycolatatopsis orientalis, 726 Amylase, 732, 909, 981 Amylose, end-to-end distances, 712 Anabaena, ferredoxin, 964 Ancestry, common see homology Angiotensinogen, 216 Angle

deformation, 206 dihedral, 198

Aniline hydroxylase, 990 Anion exchangers, 808 Anisotropy

of anomalous scattering, 1004 distribution, 193 fluorescence and phosphorescence, 191, 507, 1054-1055

Ankyrin, 281, 284 Annealing see simulated annealing Annelids, hemoglobin, 918-919 Annexins, 330, 884, 886 Anomeric ratio, of simple sugars, 713 ANS, fluorescent probe, 984 Anthracycline antibiotics, binding to DNA, 440 Anthramycin, 444 Anti-CD 15, 767 Anti-cancer agents, binding to DNA, 215 Antibiotics

and DNA topoisomerases, 99-100 glycopeptide, 726 transport proteins, 599594

Antibodies anti-idiotope, 57 catalytic, 626-628, 784 chimeric, 624 cloning, 608 combining sites, 56 engineered, 624~628 functional domains, 624 McPC, 603, 234 monoclonal, 22, 56-57, 624 production, 53 specificity, 626 structure, 56 therapeutic power, 626 to p-azophenylarsonate, 55-56 to lysozyme, 232, 233