Many hemoproteins, ranging from oxygen-carriers and electron- carries to heme enzymes, utilize protoheme as their prosthetic group. Since the primary and three-dimensional structures have been determined for a number of representative hemoproteins, it becomes feasible to analyze and rationally predict a correlation between the molecular structure and biochemical functions. Cytochrome c peroxidase (CCP) was the first heme enzyme whose crystal structure was determined. This allows a direct structural comparision of a heme enzyme with well established hemoproteins such as myoglobin, hemoglobin and the cytochromes to examine the structural basis for their functional diversity. Dr. Yonetani will investigate the spectroscopic, kinetic and enzymic properties of native and metal-substituted cytochrome c peroxidases and their interaction with cytochrome c. He is especially interested in probing the electronic and structural features of cytochrome peroxidase, particularly the prosthetic group and its environment, that can be correlated with the unique reactivity of the enzyme with hydroperoxides. This should further the understanding of the mechanism of electron transfer between two hemoproteins.
