New tools for the identification and analysis of glycans

Glycans, which are biopolymers made up of monosaccharide units linked by glycosidic bonds, are ubiquitous in biological systems. Because they decorate the surface of cells, they play a central role in virtually all cellular recognition processes and are directly implicated in almost every major disease. Their structural characterization is thus of utmost importance. Unfortunately, the isomeric complexity of glycans presents severe challenges for mass-spectrometric determination of primary structure. This is complicated by the fact that their synthesis is not template-driven as in the case of proteins. Thus, most of the powerful tools available for protein sequencing simply do not apply to glycans.
Over the last few years, we have been developing new tools for analysing released glycans by combining ultrahigh-resolution ion mobility with cryogenic vibrational spectroscopy and mass spectrometry. Ion mobility is used to separate isomeric species, and cryogenic IR spectra, which are extremely sensitive to the slightest differences in structure, are then used to identify them. The goal is to create a spectroscopic database of glycans and glycan fragments that can be used to rapidly identify them from a mixture.
This talk will demonstrate the variety of tools we have developed to identify glycans for which standards are available as well as schemes to analyse the primary structure of unknown glycans.