9723828 Bagley Low temperature infrared difference spectroscopy will be used to delineate the molecular mechanism of hydrogen binding and activation in hydrogenases. Previous infrared spectroscopic studies on the NiFe hydrogenases have shown that this class of enzymes display anomalous, intense infrared bands arising from one intrinsic carbon monoxide molecule and two intrinsic cyanide molecules coordinated to the active site Fe ion. These anomalous infrared signatures will be used for further study of the various redox states of the enzyme; for exploration of the nature of the similarities in the active sites of the NiFe and Fe hydrogenases as detected using infrared spectroscopy; determination of the nature of carbon monoxide binding in the NiFe and Fe hydrogenases; and examination of the role amino acids play in the activation of hydrogen. The overall goal of this work is to understand the mechanism underlying the hydrogenases' ability to split molecular hydrogen into protons and electrons. Understanding this process has important consequences for the development of cheap and stable catalysts for use in hydrogen production and fuel cells. In addition, the development of methodologies for handling infrared samples under strictly anaerobic conditions as required in this research should prove of general utility in infrared studies of other oxygen sensitive metallo-proteins. The research will involve participation of undergraduate students. Participation in this project will afford undergraduate chemistry students a unique opportunity to apply skills and knowledge they have learned so far while contributing to a project in modern physical biochemistry. ***
