Glycosyltransferases and their Assays

Abstract

Glycosyltransferases (GTs) are a large family of enzymes that are essential in all domains of life for the biosynthesis of complex carbohydrates and glycoconjugates. GTs catalyse the transfer of a sugar from a glycosyl donor to a variety of acceptor molecules, for example, oligosaccharides, peptides, lipids or small molecules. Such glycosylation reactions are central to many fundamental biological processes, including cellular adhesion, cell signalling and bacterial- and plant-cell-wall biosynthesis. GTs are therefore of significant interest as molecular targets in chemical biology and drug discovery. In addition, GTs have found wide application as synthetic tools for the preparation of complex carbohydrates and glycoconjugates. In order to exploit the potential of GTs both as molecular targets and synthetic tools, robust and operationally simple bioassays are essential, especially as more and more protein sequences with putative GT activity but unknown biochemical function are being identified. In this minireview, we give a brief introduction to GT biochemistry and biology. We outline the relevance of GTs for medicinal chemistry and chemical biology, and describe selected examples for recently developed GT bioassays, with a particular emphasis on fluorescence-based formats.

Non-reciprocal Interspecies Hybridization Barriers in the Capsella Genus Are Established in the Endosperm

“…Therefore, the observed correlation between precocious or delayed endosperm cellularization with respectively decreased or increased endosperm proliferation in response to interploidy hybridizations [13,44] seems unlikely to reflect a general mechanism coupling endosperm proliferation to cellularization. Our transcriptome data revealed that endosperm cellularization failure in response to interspecies and interploidy hybridizations correlated with increased expression of enzymes that hydrolyze glycosidic bonds between carbohydrates and could therefore degrade cell walls [45]. This suggests that the timing of endosperm cellularization is transcriptionally controlled and requires suppression of cell wall degrading enzymes.…”

Carbasugar Analogues of Galactofuranosides: Pseudodisaccharide Mimics of Fragments of Mycobacterial Arabino­galactan

“…The mode of binding is unknown, and the level of inhibitory activity of this pseudodisaccharide is fairly low compared to the state of the art for glycosyl transferase inhibition. [29][30][31] Nevertheless, this result demonstrates that inhibition of this medically relevant enzyme by carbasugar derivatives is possible, and in fact, significantly better inhibitors for galactofuranosyl transferases have not been reported.…”

New α-glucosides of caffeoyl quinic acid from the leaves of Moringa oleifera Lam.

“…Nucleophilic substitution at the anomeric carbon of the transferred glycosyl residue proceeds with either inversion or retention of configuration of the donor substrate [16][17][18]. Glucosides of secondary metabolites found in plants normally have a b-configuration.…”