RUI: Characterization of the Manganese Centers of Oxalate Oxidase from Ceriporiopsis subvermispora

Kennesaw State University Research And Service Foundation, Kennesaw GA

Investigators

Abstract

This project seeks to elucidate how protein environment modulates the chemistry of oxalate degradation in recombinant oxalate oxidase from Ceriporiopsis subvermispora. Oxalate oxidase catalyzes the carbon-carbon bond cleavage of oxalate to yield carbon dioxide and hydrogen peroxide. Although there is currently no structural information available for oxalate oxidase from C. subvermispora (CsOxOx), sequence data and homology modeling indicate that it is the first manganese-containing bicupin enzyme identified that catalyzes this reaction. The best characterized oxalate oxidases are from barley and wheat. These enzymes, also known as germins, contain a single cupin domain and are therefore classified as monocupins. Interestingly, CsOxOx shares greatest sequence homology with the bicupin microbial oxalate decarboxylases. The short term goals of this research are to 1) to characterize the manganese-dependence of oxalate oxidase from C. subvermispora and 2) to identify the active site of the enzyme. This research is expected to contribute to the understanding of how subtle structural changes effect remarkable functional variation in evolutionarily related proteins. Characterizing the manganese-dependence of CsOxOx is significant in order to place this enzyme in the context of other oxalate degrading enzymes and that of other cupin proteins. Identifying the active site of CsOxOx is an important problem. If only one of the manganese centers mediates catalysis, critical questions are raised concerning the function (if any) of the second Mn-binding domain and the extent to which local protein structure in each domain results in differential reactivity. Broader Impacts This project is transforming Gainesville State College (a two-year unit of the University System of Georgia) from an institution that provides excellent coursework in the sciences into one that also provides students the opportunity to participate in meaningful and important laboratory research. Undergraduate students carry out most of this work at Gainesville State College (GSC), but also have the opportunity to work with collaborators at the University of Florida and the National High Magnetic Field Laboratory in Tallahassee, FL. Student researchers are expected to communicate their research experiences to broad audiences through diverse media. Student researchers also are expected to publish their results and report research findings at professional meetings and to the regional educational community. Funds from this project are used to acquire, operate, and maintain research equipment that is not otherwise available at GSC.