William Jencks
William Platt Jencks was an American biochemist. He was noted particularly for his work on enzymes, using concepts drawn from organic chemistry to understand their mechanisms.
Career
Jencks graduated from Harvard College in 1947 with a degree in English, and earned a Doctor of Medicine from Harvard University in 1951. He interned at the Peter Bent Brigham hospital. Jencks conducted his first postdoctoral research for two years with Fritz Lipmann at Harvard Medical School. Jencks was drafted into the Army Medical Corps and was assigned to the Army Medical Service Graduate School at Walter Reed Medical Center in Washington, DC. He worked with E. L. Durrum and served as the chair of the department of pharmacology. In 1956–1957, he did a second Public Health Service postdoc with R. B. Woodward of the Harvard University Department of Chemistry. In 1957, he moved to the new graduate program in biochemistry at Brandeis University. He became professor emeritus in 1996.Much of his career focused on reaction mechanisms used by enzyme catalysts. He was particularly well known for studies of the reaction of nucleophiles with carbon. He proposed that enzymes use ground state destabilization, termed the Circe Effect, to increase the reactivity of their bound substrates. In this work he proposed the frequently misunderstood concept of one-way enzymes — enzymes that are more effective catalysts in one direction than in the other. Many of these research interests were explored in his influential text Catalysis in Chemistry and Enzymology. Jencks published close to 400 scientific papers during his career.
Jencks was a co-founder of the biannual Winter Enzyme Mechanisms Conference. He was memorialized at the 20th Enzyme Mechanisms Meeting in St. Pete Beach, Florida, several days after his death.