Approaches for site mapping and quantification of O-linked glycopeptides

As a complex post-translational event, the biosynthesis, structures, and functions of O-linked glycans have attracted research interests in various aspects. The recent development of novel technologies for the analysis of glycans and glycoproteins sheds new insights with regard to determining site occupancy, structure-function relationships, and the contributions of O-linked glycosylation to physiological and pathological processes. In this chapter, we refer to several approaches for the structural characterization and quantification of O-linked glycopeptides, with a focus on O-GlcNAc and O-Mannose modified glycoproteins.