Mass Spectrometry-Based Quantitative O-GlcNAcomic Analysis

The dynamic co- and post-translational modification (PTM) of proteins, O-linked β-D-N-acetylglucosamine modification (O-GlcNAcylation) of serine/threonine residues is critical in many cellular processes, contributing to multiple physiological and pathological events. The term "O-GlcNAcome" refers to not only the complete set of proteins that undergo O-GlcNAcylation but also the O-GlcNAc status at individual residues, as well as the dynamics of O-GlcNAcylation in response to various stimuli. O-GlcNAcomic analyses have been a challenge for many years. In this chapter, we describe a recently developed approach for the identification and quantification of O-GlcNAc proteins/peptides from complex samples.