Title:

Characterization of Glycoproteins and Protein Dynamics using Mass Spectrometry-Based Proteomics 

Abstract:

Mass spectrometry (MS) has played an increasingly important role in protein analysis. Using MS, we can comprehensively analyze proteins without antibody. More importantly, it provides a unique opportunity to globally and site-specifically characterize protein modifications. Glycosylation is one of the most common and essential protein modifications in mammalian cells. Glycoproteins contain a wealth of information about developmental and diseased statuses of cells, and aberrant glycosylation is directly related to human disease, including cancer and infectious diseases. However, due to the low abundance of many glycoproteins and the heterogeneity of glycans, it is extraordinarily challenging to globally analyze glycoproteins in complex biological samples. Based on the common features of glycans, we have developed chemical and enzymatic methods to globally analyze protein glycosylation by MS. Glycoproteins located on the cell surface are especially interesting because they regulate nearly every extracellular event. In our lab, effective methods have been developed to specifically tag surface glycoproteins, and the dynamics of surface glycoproteins was systematically quantified during the cell immune response. Furthermore, through the integration of metabolic labeling, click chemistry, and multiplexed proteomics, we investigated protein degradation, protein synthesis and its inhibition, which will also be covered in this talk. Global analysis of protein glycosylation and protein dynamics aids in a better understanding of protein functions and the identification of proteins as disease biomarkers and drug targets.