Post-translational modifications (PTMs) occur for proteins intended for both intracellular and extracellular functions. These biochemical changes to a protein can be enzymatic or non-enzymatic and may involve changes to amino acids’ side-chain functional groups and their N-termini, as well as peptide hydrolysis. Many PTMs are polar by their nature, including glycosylation, deamidation, and oxidation.
These types of polar modifications are more readily analyzed (as released species or as modified proteins) using hydrophilic interaction liquid chromatography (HILIC) because they are retained and resolved better compared to reversed-phase liquid chromatography (RPLC). In this white paper we investigate the characterization of glycosylation, deamidation, and oxidation as different types of PTMs.