Fischer, Edmond (1920– )

US biochemist who was awarded a Nobel Prize for Physiology or Medicine in 1992 with Edwin Krebs for isolating and describing the action of the enzyme responsible for reversible protein phosphorylation, a major biological control mechanism. Reversible phosphorylation is the attachment or detachment of phosphate groups to or from proteins in cells. It is at the heart of a wide range of biological processes ranging from muscle contraction to the regulation of genes.

In 1955 and 1956 Fischer and Krebs, both at the University of Washington, Seattle, USA, isolated the enzyme, called phosphorylase, involved in phosphorylation. They also discovered other enzymes, called protein kinases and phosphatase, which add and remove phosphate groups to the phosphorylase. By adding and removing phosphate groups, the enzymes change the shape of the phosphorylase molecule, switching on and off its catalytic properties.

Fischer was born in Shanghai, China, the son of Swiss parents. He was educated in chemistry at the University of Geneva, receiving his doctorate in 1947. In 1953 he moved to the University of Washington, Seattle, becoming a full professor in 1961.