Structural Analysis of Human Glycoproteins by Tandem Mass Spectrometry

Abstract

The process of glycosylation is a highly conserved mechanism among species. The enzymatic addition of oligosaccharide chain to the protein significantly changes the physicochemical properties and protein-protein interactions. Therefore glycosylation considered as a CQA (Critical Quality Attribute) for biopharmaceutical products. At this point there is no routinely used, widespread analytical method to determine glycosylation. This may derive from the fact that the term glycosylation summarizes various features. The most often examined feature is the relative abundance of glycoforms. The position of different sugar residues within the oligosaccharide chain has been less frequently analyzed. In this study we have developed a method which, in addition to the commonly investigated features, determines the structural position of the fucose residue. We have examined glycosylation of three proteins: AGP (alpha-1-acid glycoprotein), PSA (Prostate Specific Antigen) and IgG (Immunoglobulin G).