Glycosylation is one of the most prevalent co- and post-translational modifications of human proteins and is known to affect the protein properties. Glycosylation is known to be involved in many different diseases. The sialic acids at the end of the glycan chain serve as a binding site for toxins, pathogens and human lectins in a linkage-specific manner having great biomarker potential. During the development and production of biopharmaceuticals glycosylation is a critical quality attribute and therefore has to be monitored. It is known that different cell culture conditions can lead to different glycoform patterns of specific proteins. Characterization of the heterogeneous character of glycoproteins in biopharmaceuticals and in biomarker discovery can be challenging and mass spectrometry (MS) based platforms are increasingly being used for the glycosylation analysis.
In this webinar we investigate the use of CESI-MS, which is capillary electrophoresis (CE) separation combined with sheathless electrospray ionization (ESI) for biomarker discovery targeting the glycoprotein prostate specific antigen (PSA). Furthermore, in combination with a dopant enriched nitrogen gas (DEN-gas) the analysis of tryptic Fc-N-glycopeptides of a monoclonal IgG1 antibody (mAb) are explored. The precision of CESI-MS in glycosylation profiling will be compared to nano liquid chromatography (LC)–ESI–MS and matrix assisted laser desorption/ionization (MALDI)–TOF–MS. The improved repeatability and sensitivity by employing the DEN-gas will be discussed as well its application for the analysis of other glycoproteins. Moreover, CESI-MS with DEN-gas will be reviewed for the analysis of glycans after reducing-end labeling.