O-glycosylation in hinge region of mouse immunoglobulin G2b.

摘要: Mouse monoclonal immunoglobulin G2b (IgG2b) antibodies are known to contain two forms of the heavy chain that different in susceptibility protease attack. In present study, by use an affinity column containing sialic acid-binding lectins from Maackia amurensis seeds, a mouse IgG2b was successfully separated into three phenotypes, which degree sialylation chain. N-linked oligosaccharides all virtually no detected. Elution profiles lysyl endopeptidase digestion products were compared for phenotypes. The peptides eluted at retention times subjected fast atom bombardment-mass spectrometry and amino acid sequence analyses. It revealed approximately 40% O-glycosylated Thr-221A hinge region, predominantly with tetrasaccharide composed GalNAc, Gal, N-glycolylneuraminic residues. We suggest O-glycosylation renders region resistant against proteolyses A therapeutic significance is briefly discussed.