Figure 6
N-linked glycosylation mapping by IGOT showing three N-linked glycosylated sites. Tandem mass spectra of peptides showing a 3-dalton increase in mass at Asn139 (A), Asn202 (B), and Asn289 (C) after digestion with PNGase F in 18O-labeled water, suggesting that this site was previously glycosylated.