9513747 Hille This award will support the travel over three years to enable Dr. Charles Russell Hille from the Department of Medical Biochemistry at the Ohio State University to conduct collaborative research with Dr. Robert Anderson of the Department of Chemistry at the University of Auckland. The cooperative research will focus on the characterization of electron transfer within two complex oxidoreductases. Xanthine oxidase from cow's milk catalyses the oxidative hydroxylation of Xanthine to form uric acid. Studies of the four redox-active centers of this enzyme will be pursued using pulse radiolysis. Other work will focus on electron transfer within trimethylamine dehydrogenase. The pulse radiolysis data will be used to compare and contrast the behavior of these proteins with regard to the involvement of prototropic events in the observed electron transfer processes. The pulse radiolysis facilities in Auckland have been specifically designed with biological applications in mind. This project draws together the biochemical expertise of Dr. Hille with the facilities available in Dr. Anderson's laboratory.