C2-Carbon Isostere of N-acetylglucosamine as Substrate for Bacterial Polysaccharide Remodeling

Abstract

Introduction of unique structural modifications into a living cell presents opportunities to investigate and manipulate specific biological pathways and functions. Cell surface oligosaccharides represent one area where structural modifications can easily be made which allow for the investigation and manipulation of such processes. Bacterial cell surface oligosaccharides, while both structurally diverse and biological relevant, have not been extensively probed as a source for introducing chemically modified structures. In this study, we demonstrate the incorporation of an unnatural ketone containing monosaccharide, which heterogeneously is incorporated into the cell surface oligosaccharides of E. coli. Through bioorthogonal chemistry we selectively label the cell surface oligosaccharides containing the ketone modified monosaccharide with various probes, which are used to image and identify the cell surface oligosaccharides. In summary, this study presents a facile and effective method for the in vivo incorporation of a ketone containing monosaccharide which can be exploited for studying the bacterium.