Daniel Edward Koshland, Jr., president of the American Society of Biological Chemists in 1973, was born in New York City. He received his B.S. in chemistry from the University of California, Berkeley, in 1941 and then accepted a job at the Shell Chemical Company in Martinez, California. During World War II, he served as a group leader in the Manhattan Project, working on the purification of plutonium. At the war's conclusion, Koshland decided to remain at the University of Chicago and entered a Ph.D. program in biochemistry. His research involved using radioactive carbon-14 to study chemical reactions in the metabolism of glucose. He received his Ph.D. in 1949.
For his postdoctoral work, Koshland moved to Harvard University, where he worked under the direction of Paul Bartlett. It was here that Koshland became interested in enzymes. When he completed his 2-year tenure at Harvard, Koshland accepted an appointment at the Brookhaven National Laboratory and remained there for 14 years eventually becoming senior biochemist. At Brookhaven, Koshland developed his induced fit theory of enzymatic action, which posits that enzymes change shape as they react with other molecules. This, in turn, led to his sequential model for explaining the kinetics of allosteric enzymes. In 1964, Koshland was offered an appointment in the Department of Biochemistry at the University of California, Berkeley. He assumed his new position as professor of biochemistry in 1965 and served as chair of the department between 1973 and 1978.
Among Koshland's many honors were the Albert Lasker Award for Special Achievement in Medical Science, the National Medal of Science, the American Chemical Society's Pauling and Edgar Fahs Smith Awards, the Rosenstiel Award, the Wateford Prize, and election to the National Academy of Sciences. Koshland was editor-in-chief of the journal Science from 1985 to 1995 and a member of the Journal of Biological Chemistry editorial board. A grant from Koshland established the National Academy of Sciences' Marian Koshland Science Museum in honor of his late wife. The museum focuses on increasing the public understanding of science, which was one of Marian Koshland's passions.