Fast and Comprehensive Characterization of Human IgG1 by High-Resolution Accurate-Mass Mass Spectrometry
Today, many newly approved drugs are derived from recombinant monoclonal antibodies (mAbs). mAbs produced from mammalian cells may be present in multiple isoforms due to alternate splicing, post-translational modification (PTM), and variations in genetic code. These variations of mAb can result in different biological consequences. Due to these differences, it is required to identify and characterize mAbs variants routinely to ensure the quality of therapeutic products. The analysis of intact mAb and partial proteolysis of mAb provides the number of protein variants and isoforms. For this purpose, we have developed a rapid, robust workflow to examine the heterogeneity of mAb products at the intact level.
Although human IgGs are highly homologous and share more than 95% sequence homology, each mAb drug product displays variable heterogeneity due to differences in manufacturing processes and storage conditions. Human IgGs constitute a variety of enzymatic and chemical modifications, such as deamidation, isomerization, oxidation, glycosylation, and terminal cyclization. The detailed analysis of post-translational modifications (PTMs) present on mAbs is required to ensure both safety and efficacy. Due to the heterogeneity of mAbs, thorough characterization is very challenging. We have developed a comprehensive antibody characterization workflow, coupling capillary LC with High-Resolution/Accurate-Mass (HR/AM) mass spectrometry.