Imaging Cellular Glycan Epitopes and Glycoproteins Using Glycosyltransferases

Zhengliang L. Wu, Anthony Person, Matthew Anderson, Barbara Burroughs, Timothy Tatge, Yonglong Zou, Lianchun Wang, Robert Sackstein, and Todd Geders


Glycans are basic molecules in all living organisms. However, they are not well characterized due to the unavailability of specific and high-sensitivity detection reagents. We describe here a method for enzyme-based glycan imaging using glycosyltransferases. Azido-sugars are incorporated into target glycans followed by click chemistry-based conjugation with fluorescent reporters. Since glycosyltransferases have well defined substrate specificities, this method offers precise detection of target glycans. Examples include imaging of of O-GlcNAc, O-GalNAc (Tn antigen), T antigen, sialyllactosamine (sLN), hyaluronan (HA), and heparan sulfate epitopes in different cell lines. This highly specific technique will facilitate the detection and characterization of biologically important glycans.