Christian B. Anfinsen (1916-1995) Remembering His Life and His Science

Christian B. Anfinsen died on May 14, 1995. At the time, he was Professor of Biology at The Johns Hopkins University. What follows is a brief tribute to this extraordinary biochemist and extraordinary human being. Chris was always “Chris” to all who worked with him-right down to his most junior students andfellows. He seemed embar- rassed to be called “Dr. Anfinsen.” He was born in Monessen, Pennsylvania and, following graduation from Swarthmore in 1937, he moved to the University of Pennsylvania, where he received his Masters degree in organic chemistry in 1939. He obtained his Ph.D. degree in Biological Chemistry from the Har- vard Medical School in 1943 under the tutelage of Baird Hast- ings, and remained at Harvard until 1950, first as Instructor and then as Assistant Professor of Biological Chemistry. In 1950, a signal event occurred that was profoundly to shape all that followed. Dr. James A. Shannon, then Director of the National Heart Institute, invited Chris to become chief of the Laboratory of Cellular Physiology. He left Boston and moved to Bethesda. Here began a journey that would ultimately lead to the Nobel Prize. Chris had long been interested in the problem of protein bio- synthesis, and his first five years at the NIH saw publication of several papers on this subject and on lipoprotein metabolism. Yet, although he worked on important biological problems, he thought like a chemist-and this thinking was strongly influ- enced by the work of Frederick Sanger on determination of pro- tein amino acidsequences. Consequently, in 1954 Chris set out for Cambrid_ce to learn how to sequence a protein and, follow- ing this, in the same year, he studied in Copenhagen with K. Linderstrom-Lang at the Carlsberg Laboratory to learn protein biophysical chemistry. The Carlsberg housed a premier group of protein chemists at Chris returned to the NIH and set about to establish the struc- the time, and it was here that Chris met Bill and lnge Harring- tural order of pairing of the eight cysteine residues of bovine ton and John and Charlotte Schellman-ameeting that was to pancreatic ribonuclease to form the four disulfide bonds of kindle Chris’ interest in playing chamber music. Linderstrom- the native structure. Stanford Moore and William H. Stein at Lang made an indelible impression upon all of his collaborators the Rockefcller Institute already had determined much of the and he was also an accomplishedviolist. Chris, already a good primary structureof this enzyme, andto do so they oxidatively pianist, bought a viola, Bill Harrington purchased a cello, and cleaved the disulfide bonds irreversibly to form sulfonic acid they began to take lessons. One day soon after, Chris andBill groups. In contrast, Chris chose to cleave the disulfides by re- walked into a music shop in Copenhagen and asked for a Mozart duction in the presence of strongdenaturing solvents (e.g., urea). quartet “without any sharpsor flats!” An ensemble was born - Under these conditions, of course, the proteindisplayed no en- Flossie Anfinsen and Inge (violins), John and Bill (cellos) and zymic activity. Among many experiments alongthese lines, one Charlotte (viola). Chris onceremarked that, inspite of no sharps/ turned out to be astounding. Upon removalof the urea and re- no flats, the quartet kept him busy for a long time. He loved ducing agent, a large fraction of enzyme activity re-appeared the viola and he played it for the rest of his life. in the presence of air. 2237 2238 M. Young

This singular result implied that the correctly paired disul- The second major contribution was the developmentin 1968 fide bonds had reformed by reoxidation! Chris immediately of the technique of affinity chromatography as a method for recognized the significance of this experiment, which was that selective purification of enzymes. Finally, and perhapsmost cen- the chemical folding and bonding information containedin the tral to Chris’ interests, was the work on staphylococcal nucle- amino acid sequenceitself was sufficient to direct refolding of ase. He wanted to synthesize chemically a catalytically active the molecule to yield its native structure. Thebasis for thefinal enzyme from scratch. For this purpose he chose staphylococ- stage of protein biosynthesis was now solved. cal nuclease, and his goal was realized following coupling of pep- From 1956 to 1963, many papers on the refolding process tide fragments prepared by solid phase synthesis. arose from the NIH laboratory-a laboratory thatbecame a rich In 1972, Chris was awarded the Nobel Prize in chemistry, a training ground for postdoctoral fellows, manyof whom were prize that he shared with William H. Stein and Stanford Moore. dedicated young physicians pursuing careers in academic med- Perhaps the most quintessential example ofthis man’s humble icine. This period also witnessed development of Chris’ strong and self-effacing personality came from his response to this scientific as well as emotionalties to the Weizmann Institute of award. He simply felt uncomfortable in talking about it, or in Science and the Stateof Israel. In particular, Michael Sela was receiving congratulations, and he would swiftly try to change a frequent visitor and he contributed greatly to the scientific the subject of conversation. life of the laboratory. Chris became a member of the Board Chris took few respites from science, but he liked to play of Governors of the Weizmann Institute and remainedso until Scriabin piano sonatas and the viola. He also loved ocean sail- his death. ing, of which many stories abound from friends who voyaged In 1959, Chris wrote a small book. It was entitled the Molec- with him. Chris took risks! Facing 30 feet swells in a storm, he ular Basis of Evolution (John Wiley, New York). In it, he set could go below and sleep with abiding faith in another crew forth his ideas on protein structure and protein folding and on member who stood watch at the helm. Or, while exploring shoal the importance of protein structureanalysis for an understand- waters, running agroundwas not uncommon. All of this is not ing of evolutionary processes. (He often said thathe wrote the surprising because Chris also took risks in science-risks that book as much for himself as for anyoneelse.) That single mono- paid handsomely. Above all, both his scientific and seafaring graph proved to have a marked influence on the thinking of exploits provided him with much sheer fun. members of his laboratory at the time, well as as uponthose who In 1982, Chris was invited to become Professor of Biology at came later. Indeed, several individuals were stimulated to work the Johns Hopkins University, where his longtime friend and in the Anfinsen laboratory largely because they had read this colleague Bill Harrington was chairman of the department. At small, but scientifically rich publication. this time, Chris embarked on a new enterprise- the structure In 1963, Chris was invited to become Professor of Biologi- and function of enzymes from hyperthermophilic bacteria. He cal Chemistry at his Ph.D. aha mater, the Harvard Medical supervised graduate students, developed a stimulating research School. However, he remained at Harvard but one year, forin program and taught courses. For nearly 40 years, he had been 1963 he was asked to return to the NIH to directa new labora- an editor of Advances in Protein Chemistry (currently with John tory in the Institute of Arthritis and MetabolicDiseases. He ac- T. Edsall, Frederic M. Richards, and David Eisenberg). At the cepted the offer. Chris himself named this new laboratory the time of his death, his research was funded by the National Sci- Laboratory of Chemical Biology, and that name couldserve by ence Foundation and he was busily editing the next issue of itself as a statementof his scientific philosophy- biological un- Advances. derstanding was the goal, hut its attainment was to he reached Chris received many awards and honorary degrees. Hewas through chemistry. Pertinent to Chris’ return to the NIH was a member of the National Academy of Sciences, the Royal Dan- the humorous story concoctedby Howard Schachman and of- ish Academy, the Pontifical Academyof Sciences, and he was ten told at Gordon conferences of the time. Howard’stale con- a Past-President of the American Society of Biological Chem- cerned the departure of NIH scientists who had been lured to ists. He had three children fromhis marriage to Flossie Anfin- accept more lucrative university professorships. This pathway $en (Carol Craft, Margot Britton, andChristian B. Anfinsen 111) was called “the NIH shunt” and the reactionwas catalyzed by and five grandchildren. From his second marriage, he leaves his the enzyme “money transferase.” Howard noted that Chris just wife Libby. proved that this pathway was freely reversible. To all who knew him, the kindness, sensitivity, and social con- Chris remained at the NIH for thenext 18 years and he was science of Chris Anfinsen were cornerstones of his life. It is not surrounded by an extraordinarilytalented group of young scien- that he will not be forgotten. Rather, he will always be vividly tists. Among many creative contributions, three areparticularly remembered. noteworthy. Chris had long realized that simple air-induced re- Many individuals worked in Chris Anfinsen’s laboratory over oxidation of reduced ribonuclease was a slow process that by the years. Chris himself compiled a list of these scientists dur- itself could not account for the more rapid andefficient in vivo ing the year before his death and I present it here in tribute to biosynthesis of the enzyme.So a search was initiated for a frac- him and to them. tion of beef liver that might enhance the rate of oxidation. In 1966, he and his collaborators identified and purified an enzyme that catalyzed sulfhydryl-disulfide interchange. This enzyme, MICHAEL YOUNG protein disulfide isomerase, became a chaperone-although that University of Florida name was ultimately coined by others many years later. Gainesville, Florida 32610-0266 Christian B. Anfisen (1916-1995) 2239

Members of the Anfinsen Laboratory

A. Seetharama Acharya M. Flavin Edward D. Korn Urs Th. Ruegg Herman L. Ammon Angelo Fontana John S. Kovach David H. Sachs Generoso Andria Caye Franklin Floyd Kregenow Guillermo Sanchez Antonio Ballesteros-Olmo Donald S. Fredrickson Henry Kronenberg Alan N. Schechter Robert Barton Theodore Friedmann S. J. Leach Peter W.Schiller Giandomenico Basile Sara Fuchs Robert Lesick Sheldon Schlaff Janine R. Beisson Bruce Furie Albert Light B. Schneider Mary Anne Berberich John A. Gerlt Loren Lipson Michael Sela Shelby L. Berger David Givol Patrick E. Lorenz Parker A. Small, Jr. Jay A. Berzofsky Robert F. Goldberger Kenneth L. Luskey Oliver H. Smith Francesco Blasi Robert S. Gordon Sally L. Marchesi Marco Soria Robert E. Canfield R. Gordon Could Michael N. Margolies Daniel Steinberg Robert Coifman John H. Griffin 0. Wesley McBride J. Robert Suriano Gary R. Craven Dalia Curari-Rotman Thomas C. Merigan J. William H. Sutherland Pedro Cuatrecasas Edgar Haber Elemer Mihalyi Brian F. Tack John B. Curd Hanspaul Hagenmaier Ladislav Moravek Hiroshi Taniuchi Charles L. Cusumano Roy Hantgan Kathleen Mullinix Kenneth Thomas Richard Davis Paul A. Hargrave Paola Di Natale Peter Tishler Roger G. Deeley William F. Harrington Motonori Ohno Agnes Ullmann Francesco DeLorenzo James N. Heins Gilbert S. Omenn Martha Vaughan Carlo DiBello Nanine Henderson David Ontjes Pal Venetianer William J. Dreyer Richard Hendler Indu S. Parikh Robert Vigna Ben M. Dunn David J. Herzig Theodore Peters, Jr. Tikvah VogeI David East Gene Homandberg James M. Phang Frederick H. White, Jr. Dan Eilat Gennaro llliano Sidney Pollack Meir Wilchek S. Walter Englander Nubuo Izumiya Harvey Pollard Bernard Wildi Charles J. Epstein Ikunoshin Kat0 John T. Potts, Jr. Kerry T. Yasunobu Henry R. Epstein Arnold Katz Sitka Pradhan Michael Young Robert P. Erickson W. Wayne Kielley David C. Richardson Neal S. Young Ernst A. Fischer Stanley G. Korenman Martin Rodbell Allen R. Zeiger Waldo R. Fisher

~~ ~~ *We hope that the above list is complete, and we sincerely regret any omissions.