Profiling O-GlcNAcylation with Mass Spectrometry

O-linked β-N-acetylglucosamine modification (O-GlcNAcylation), one universal posttranslational modification commonly found in nuclear and cytoplasmic proteins, shows significant roles in a variety of biological processes, such as signal transduction, transcriptional regulation, stress response, apoptosis, and cellular signaling and metabolism. Moreover, O-GlcNAcylations with abnormal expression levels have proven to be closely associated with many diseases including Alzheimer’s, diabetes, tumors, etc. Therefore, sensitive and high-throughput profiling of O-GlcNAcylation is important for structure-function mechanism elucidating of O-GlcNAcylated proteins with high heterogeneity as required for glycomics. Mass spectrometry (MS) with high sensitivity and throughput properties has become widely used for comprehensive characterization of O-GlcNAcylation, enabling in-depth understanding of their biological roles these years. Herein, the chapter would provide a comprehensive update of MS-based methodologies for quali-quantitative characterization of O-GlcNAcylated proteins.