Mass spectrometry-based analysis of IgG glycosylation and its applications

Human immunoglobulin G (IgG), which is a major class of globulin antibodies with a typical immunoglobulin monomer structure, is mainly involved in immune activities such as binding antigens and activating the complement system. Glycosylation, an important post-translational modification of proteins, is found highly conserved on IgG, having a significant impact on the structure and function of IgG. Currently, mass spectrometry (MS) has been widely used in the analysis of glycosylated IgG, and new optimized and improved MS methods are continuously proposed in sample pre-treatment, data acquisition and analysis, etc. This review highlights the MS-based detection techniques for glycosylated IgG and discusses the application of these methods in the diagnosis of clinical diseases, discovery of biomarker, and biopharmaceuticals.