Perspective and Review of Mass Spectrometric Based Sulfoglycomics of N-Linked and O-Linked Oligosaccharides

The research area of glycomics is maturing and it is realized that it is as difficult to identify the relevance of glycosylation amongst biological house-keeping as it is with any of the other omics techniques. This review focuses on sulfoglycomics of N-linked and O-linked oligosaccharides to identify relevant biological glycomics questions. The review describes how sulfated oligosaccharides have been analyzed in the past, with the focus on MS and its current application using ESI and MALDI. Also included are the particular issues of sample preparation of sulfated oligosaccharides, including enrichment and separation using capillary and nano liquid chromatography. Structural characterization of sulfated oligosaccharides is currently carried out by collision induced dissociation, but recent developments focus on increasing the structural information by improved derivatization techniques followed by MS analysis and fragmentation of derivatized intact sulfooligosaccharides. Significant progress has been shown in this field in the application of permethylation derivatization. Current trends for fragmentation of biomolecules using novel techniques are also discussed with emphasis on sulfoglycomics. The conclusion of the review is that in order to understand the largely unexplored area of sulfation of oligosaccharides, there are techniques that need to be adapted and optimized to address the structural characterization, ranging all the way from appropriate sample preparation to effective MS analysis.