Glycosyltransferase enzymes produced by Micromonospora echinospora bacteria reversibly catalyze complex organic reactions between sugars and other molecules.

Conventional industrial techniques for glycosylating organic compounds rely upon multi-step organic synthesis reactions; these reactions usually require toxic reagents and solvents and are not readily reversible. Glycosyltransferase enzymes represent a superior way to perform the same task. Not only do they not require toxic compounds, they also perform the reaction in one reversible step. The ramifications of this reversibility are that the relative abundance of the modified and un-modified forms of the compound can be regulated via addition or removal of the different forms.


"Glycosyltransferases (GTs) constitute a superfamily of ubiquitous enzymes that attach carbohydrate moieties to biological molecules...[they are] an essential class of ubiquitous enzymes, are generally perceived as unidirectional catalysts. In contrast, we report that four glycosyltransferases from two distinct natural product biosynthetic pathways--calicheamicin and vancomycin--readily catalyze reversible reactions allowing sugars and aglycons to be exchanged with ease...the reversibility of GT-catalyzed reactions may be general and useful for generating exotic nucleotide sugars...[GTs are] caltalysts that drive the formation of glycosidic bonds from nucleotide diphosphate sugar (NDP-sugar) donors and aglycon acceptor...[Also, recently they] were found to catalyze three new reactions: (i) the synthesis of exotic NDP-sugars from glycosylated natural products, (ii) the exchange of native natural-product glycosides with exogenous carbohydrates supplied as NDP-sugars, and (iii) the transfer of a sugar from one natural product backbone to a distinct natural-product scaffold." (Zhang et al. 2006:1291)

"The exploitation of GT-catalyzed reaction reversibility may facilitate the use of glycosylation as a tool to modulate the activity of therapeutically important natural products...GT-catalyzed reactions could be modulated via simple adjustments in relative substrate concentrations. Glycosyltransfer reversibility could be exploited to synthesize valuable rare NDP-sugars, exchange one sugar on a core scaffold for another, or transfer sugars from one scaffold to another." (Zhang et al. 2006:1293)

Journal article
Exploiting the Reversibility of Natural Product Glycosyltransferase-Catalyzed ReactionsScienceJanuary 19, 2017
C. Zhang