Judith P. Klinman

Biography

 Judith Pollock Klinman, President of the American Society for Biochemistry and Molecular Biology in 1998, was born in Philadelphia, Pennsylvania. She received her A.B. and Ph.D. from the University of Pennsylvania in 1962 and 1966, and then performed postdoctoral research with David Samuel at the Weizmann Institute of Science in Israel and with Irwin Rose at the Institute for Cancer Research in Philadelphia, Pennsylvania. She was an independent researcher at the Institute for Cancer Research for many years before moving to the University of California, Berkeley, in 1978, where she is now a professor of chemistry and of molecular and cell biology.

Research Interest

 Klinman has contributed to the understanding of the fundamental properties that underlie enzyme catalysis. Early in her career, she developed the application of kinetic isotope effects to the study of enzyme catalysis, showing how these probes can be used to uncover chemical steps, to determine kinetic order, and to obtain substrate dissociation constants. In 1990, she demonstrated the presence of the neurotoxin 6-hydroxydopa quinone (TPQ) at the active site of a copper-containing amine oxidase from bovine plasma, overcoming years of incorrect speculation regarding the nature of the active site structure and opening up the currently active field of protein-derived cofactors. Subsequent work from her group showed that the extracellular protein lysyl oxidase, responsible for collagen and elastin cross-linking, contains a lysine crosslinked variant of TPQ. Since the 1990s, Klinman's kinetic studies of enzyme reactions have demonstrated anomalies that implicate quantum mechanical hydrogen tunneling in enzyme-catalyzed hydrogen activation reactions. In recent years she has developed a unique set of experimental probes for determining the mechanism of oxygen activation. These probes are beginning to shed light on how proteins can reductively activate O2 to free radical intermediates, while avoiding oxidative damage to themselves.