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NEWS OF THE WEEK
NOBEL PRIZES: Merrifïeld wins chemistry award
R. Bruce Merrifield, John D. Rockefeller Jr. Professor at Rockefeller University in New York City, has been selected to receive the 1984 Nobel Prize in Chemistry. Merrifield, a protein biochemist, is being awarded the prize for his development in the early 1960s of a method of solid-phase synthesis of peptides.
The Royal Swedish Academy of Sciences, which selects chemistry prizewinners, calls the technique "a completely new approach to organic synthesis'' that has "brought about a revolution in peptide and protein chemistry" and led to the synthesis of thousands of different peptides. Merrifield's general principle also is used for synthesizing other b iopolymers , part icular ly oligonucleotides, which are important in hybrid DNA research, the Swedish academy says.
Before Merrifield's work, peptides were synthesized according to the method worked out by an earlier Nobel Prize winner, Emil Fischer. In his technique, the carboxylic acid group of one amino acid and the amino group of another were reacted with protecting groups and the two nonprotected ends allowed to react with one another to form a peptide bond. This dipeptide was purified, one of its protective groups removed, and the entire unit reacted with another partially blocked amino acid to produce a tripeptide. After many repetitions, a long-chain polypeptide could be built up. But the time involved and the loss of product in the repeated purifications required after each peptide bond synthesis put a practical limit of about eight or nine amino acid residues in a peptide synthesized by this method.
Merrifield attaches the first amino acid of his peptide chain through
Merrifield: peptide synthesis method
its carboxylic group to an insoluble polystyrene support. Thus, the product becomes part of a solid phase, and by-products and unreacted starting materials can be removed after each synthetic step by filtration and washing of the polymer. Only when the entire synthesis is complete is the peptide removed from the solid support. The process is much faster, and, even more important, the yield in each individual step can be increased with this technique to 99.5% or better. By this method a peptide containing 100 amino acid residues can be synthesized with an overall yield of 61%, compared with a theoretical yield in the neighborhood of 0.003% for the same synthesis without the solid support.
Merrifield and his coworkers at Rockefeller have used the technique
to synthesize several important peptides and proteins including brady-kinin, insulin, and ribonuclease. They also automated the technique, producing in 1965 the first working model of an automatic peptide synthesizer. Peptide synthesis is now done routinely using commercially available automatic synthesizers. A similar technique also has been applied to the synthesis of nucleic acid polymers, where automated apparatus that can be programed to synthesize the desired product are now in wide use. "Although Merrifield has not worked in [the area of DNA synthesis] himself, it is clearly his ideas which have found a new application here," the Swedish academy says.
This year's physics prize is to be awarded jointly to Carlo Rubbia, an Italian physicist who divides his time between the European Organization for Nuclear Research (CERN) in Geneva and Harvard University, where he is professor of physics, and Simon Van der Meer, a Dutch engineer who also works at CERN. Rubbia and Van Der Meer will receive the prize for "their decisive contributions to the large project which led to the discovery of the field particles W and Z, communicators of weak interaction," the Swedish academy says.
Discovery of the W and Ζ particles was announced only last year by Rubbia and large teams of collaborators working with CERN's super-accelerator. It was Rubbia's idea in the mid-1970s to convert an existing large accelerator into a storage ring for protons and antiprotons, where head-on collisions between the stored particles could take place and W and Ζ particles, if they existed, might be detected. Van der Meer invented a method for densely packing and storing protons and anti-
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protons that made the collision experiments possible.
The Nobel Prize in Physiology or Medicine this year is divided three ways among theoretical immunolo-gist Niels K. Jerne, a Danish scientist who is professor emeritus of the Basel Institute of Immunology in Switzerland, Georges J. F. Kôhler, a West German immunologist, also at the Basel Institute, and Argentinean Cesar Milstein, who heads the division of protein and nucleic acid chemistry at Cambridge University in England.
According to the Karolinska Institute, which selects the prizewinners in medicine, Jerne is the leading theoretician in immunology of the past 30 years. "In three main theories, he has elucidated central issues concerning specificity, development and regulation of the immune system in a comprehensive and convincing way/ ' the institute says. "By his theories, Jerne has
Nobel science prizewinners ( clockwise from bottom left) Milstein, Jerne, and Kôhler
outlined the development of modern immunology."
Kôhler and Milstein will receive their share of the prize for developing in the mid-1970s a method to produce monoclonal, or identical, antibodies with predetermined specificity using hybridoma cells. Their method, in which antibody-producing cells are immortalized by fusing them with the tumor cells, allows unlimited production of monoclonal antibodies with the predetermined specificity. It has opened up new avenues for detailed study of the immune system as well as new methods for characterizing diseases and treating them. Π
ACS election ballots mailed Ballots for this fall's ACS national election were mailed Oct. 4. If your ballot hasn't arrived yet, you may request that a duplicate ballot be sent to you by calling the ACS Office of the Assistant Secretary (202) 872-4510 no later than Nov. 1. Deadline for receipt of all marked ballots at ACS headquarters in Washington, D.C., is Nov. 13.
U.S. urged to lead in tropospheric chemistry In what one science manager terms the "most imaginative report the National Science Academy has produced / ' a panel of atmospheric chemists calls for the U.S. to take the lead in a global effort to understand the chemistry of the troposphere—that part of the atmosphere in which humans live and pollute.
The panel, chaired by Robert A. Duce of the University of Rhode Island, is asking the nation to do something rather radical: commit scientific expertise for a long period of time to a fundamental exercise that has no immediate payoff. But its plan for action spelled out in "Global Tropospheric Chemistry" is not just an intellectual exercise. As the panel's vice chairman Ralph Cicerone, head of the atmospheric chemistry division at the National Center for Atmospheric Chemistry, argues, the U.S. needs to extricate itself from the "crisis response mode" that has characterized its response to pollution problems of the past 15 years.
To do that, basic questions of how chemical systems of the biosphere— the land and oceans—interact with the chemistry of the troposphere, and in turn, how tropospheric chemistry governs global temperature need to be answered. "We're not asking the U.S. government to walk away from pollution crises such as acid rain and the greenhouse effect. We, as a panel, are trying to lay the scientific framework to allow the U.S. and others to get ahead of these problems," Cicerone explains.
That framework would build a coordinated research effort to answer basic questions about processes controlling the chemistry of the troposphere. What mechanisms control the input of trace chemicals to the troposphere? What controls the long-range transport and transformation of these chemicals? And, ultimately, how are these substances removed from the troposphere?
To answer these questions, the global tropospheric chemistry program, as proposed, would evaluate biological sources of chemical substances, determine the global distri-
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