Bioorganometallic Chemistry of Enzyme Active Sites with Focus on Hydrogenase

Texas A&M Research Foundation, College Station TX

Investigators

Abstract

The Research award in the Inorganic, Bioinorganic and Organometallic Chemisry program supports work by Professor Marcetta Darensbourg at the Texas A&M University in College Station, TX, to carry out fundamental studies on small molecule models of enzyme active sites responsible for controlling hydrogen metabolism in nature. In this research, synthetic analogues of the unique metal-organic fragments found in hydrogenase enzymes are prepared and assayed for their ability to mimic the hydrogen-producing and hydrogen-consuming catalysis found in organisms that subsist on a micro-hydrogen economy. The atom-atom connections, the geometrical structure, and spectroscopic footprints of these natural catalysts are reproduced in the small molecules. The intricate and facilitating role of the surrounding protein matrix is approached by imbedding the new molecules in polymer beads and cyclodextrins. By this approach we develop understanding of the way Nature has engineered hydrogen processing ability into base metal constructs of iron and nickel, whereas commercial fuel cells must rely on expensive and resource-limited platinum. Students at all levels (graduates and undergraduates) are excited by the chemistry of fuel cells and interest in hydrogen as an energy carrier is high. In the process of opening young minds to the needed research in alternative energy sources and challenges, inspiration from nature leads into the literature of biology, biochemistry, biophysics, as well as synthetic inorganic chemistry. Our culturally diverse research group works as a team in projects to encourage interest in science in grammar school children; undergraduates from historically black colleges and universities and from South Texas, largely Hispanic colleges, join the research group to help in the projects through summer research. A home-run from this work would result in hydrogen processing catalysts feasible enough to serve as a molecular fuel cell electrode, replacing platinum as a fuel cell electrode, and to make energy-efficient fuel cell technology feasible for a broader range of applications.