Using Simple Donors to Drive the Equilibria of Glycosyltransferase-Catalyzed Reactions

We report the ability of simple glycoside donors to drastically shift the equilibria of glycosyltransferase-catalyzed reactions, transforming NDP-sugar formation from an endo- to an exothermic process. To demonstrate the utility of this thermodynamic adaptability, we highlight the glycosyltransferase-catalyzed synthesis of 22 sugar nucleotides from simple aromatic sugar donors as well as the corresponding in situ formation of sugar nucleotides as a driving force in context of glycosyltransferase-catalyzed reactions for small molecule glycodiversification. These simple aromatic donors also enabled the first general colorimetric assay for glycosyltransfer, applicable to drug discovery, protein engineering, and other fundamental sugar nucleotide-dependent investigations. This study directly challenges the general notion that NDP-sugars are ‘high-energy’ sugar donors when taken out of their traditional biological context.