Discovery and characterization of unusual O-link glycosylation of IgG4 antibody using LC-MS

Abstract

4The analysis of several batches of commercial biopharmaceutical product Dupixent using top-down intact mass spectrometry revealed that this immunoglobulin IgG4 features a small amount of O-link glycosylation in Fab region. This is the first report of an O-link glycosylation in IgG4 antibody. The paper describes most likely structure of the O-link glycosylation as well as probable location(s). The relative quantification showed only small quantity of the modification but appearing consistently in several batches of Dupixent. The O-link glycosylation site was characterized by standard tryptic peptide digestion and LC-MS analysis approach.