Glycosyltransferase Mechanisms and Inhibition

University Of Florida, Gainesville FL

Investigators

Abstract

0091881 Horenstein Glycosyltransferases are enzymes that catalyze the creation of glycosidic bonds to sugars. These enzymes are responsible for the creation of an incredibly diverse and important group of compounds that range from cellulose and starch to the heterogeneous oligosaccharides that are found at the surface of cells. The mechanisms by which these enzymes work are not well characterized. The research described here is aimed at elucidation of glycosyltransferase mechanisms, in particular the sialyltransferase and trans-sialidase enzymes. These enzymes catalyze formation of glycosidic bonds to N-acetylneuraminic acid, a negatively charged sugar often located at the non-reducing termini of oligosaccharides on the cell surface. The four specific aims of this work are to measure oxygen-18 isotope effects for sialyltransferase and trans-sialidase, use mutagenesis to perform chemical rescue of trans-sialidase, analyze the isotope effects with ab-initio computational techniques, and synthesize novel inhibitors of sialyltransferases. The results of these studies will allow for a deeper understanding of how these enzymes function and provide information required for manipulation of their activity. Further, the mechanistic information dovetails into the synthetic work by providing the basis for logical inhibitor design.