Sharon Murphy, Ph.D. is a professor in the Department of Biochemistry, Molecular Biology and Biophysics and the Director of Graduate Studies BMBB Graduate Program. Dr. Murphy received her Doctorate from the University of Colorado.
Her research interest include nicotine metabolism in smokers and are on-going to investigate the influence of individual differences in nicotine metabolism on smoking behavior and nicotine dependence. Her studies in the laboratory have characterized P450 2A6 and P450 2A13-catalyzed metabolism of both nicotine and cotinine. P450 2A6, which is present in human liver is 94% identical to the extrahepatic enzyme, P450 2A13 found in the lung. Recently her laboratory determined that both enzymes are inactivated during nicotine metabolism, and are investigating the mechanism of this inactivation. P450 2A6 and P450 2A13 are also catalysts of the metabolic activation of the tobacco specific carcinogens NNN and NNK. However, despite the similarity of these two enzymes, they catalyze NNK metabolism with strikingly different efficiencies. Metabolism by site directed mutagens of these two enzymes are being studied to investigate these structure activity relationship. Polymorphisms of both P450 2A6 and P450 2A13 exist and her laboratory and others are studying the influence of enzyme variants on nicotine and nitrosamine metabolism.
