Glycosylation is one of the most common posttranslational modifications in proteins of eukaryotic cells. It have been demonstrated that the glycosylation of a protein has a significant effect on the safety and efficacy of recombinant biotherapeutic proteins, with reports of glycosylation affecting the tertiary structure, solubility, stability, immunogenicity, in vivo clearance, and bioactivity of the protein. One recent trend is the increasing emphasis on understanding the nature of the different glycan structures involved in the protein glycosylation. Given that various cell lines, expression hosts and protocols can result in different glycosylation patterns, measuring and understanding glycosylation by various analytical techniques is crucial. Furthermore, to understand batch-to-batch variability and to compare recombinant therapeutic proteins with the plasma derived variant, it is necessary to determine where glycosylation occurs as well as the structure and content of the individual sugars. The first task is relatively straightforward using peptide mapping experiments however the latter represents a much more challenging task, and requires a whole suite of MS-based methods coupled with various separation methods.
Overall, in order to support the development and production of new recombinant proteins with improved efficacy and pharmacokinetics and a reduced risk of adverse immunological reactions, there is a regulatory requirement for the comprehensive characterisation of protein glycosylation.
The lecture will give an overview of different methods and technologies used for N-and O glycan characterization. Our major focus is to combine quantitative profiling methods using different label strategies and fluorescent detection in line with mass spectrometry based identification of the separated glycan structures.