Robert Bruce Merrifield

Robert Bruce Merrifield, (1921-2006), American biochemist and Nobel Prize winner. Merrifield developed a laboratory method for the automatic synthesis of proteins. As a result, the time necessary for this process was cut from months to mere days. His work also enabled researchers to develop many synthetic antibodies and vaccines. For his contributions to the synthesis of proteins, Merrifield was awarded the 1984 Nobel Prize in chemistry.

Born in Fort Worth, Texas, Merrifield received a Ph.D. degree from the University of California at Los Angeles (UCLA) in 1949. That year, he joined the Rockefeller Institute for Medical Research (now Rockefeller University) in New York City, where he was named chair of biochemistry in 1966. Merrifield became John D. Rockefeller, Jr., Professor at Rockefeller University in 1983.

Proteins are chains of amino acids linked by peptide bonds. Peptides have the same structure as proteins but have shorter chains of amino acids. Scientists artificially create peptides, using their chemical components, in order to manufacture whole proteins. Before Merrifield developed his technique in the late 1950s, this process was tedious and time-consuming. To get the amino acids to link in the proper sequence, certain parts had to be blocked so that only the desired sites would interact and bond. Between each step, the peptide had to be isolated and purified. When the by-products of the previous reaction were washed away, part of the peptide structure was inevitably lost. Merrifield's idea was simple but effective: He bonded the amino acids, one at a time, to a polystyrene resin that could not be dissolved. That way, no matter what solvent was used, the structure would remain intact during washing. When the chain was complete, the solid resin could be removed chemically. In 1965 Merrifield used his method, called solid-phase peptide synthesis, to create the human protein insulin in only 21 days. He also helped design and construct a machine to perform automated peptide synthesis. In 1969 he became the first to synthesize a naturally occurring enzyme.