Localization ofo-glycosylation sites of MUC1 tandem repeats by QTOF ESI mass spectrometry

✍ Scribed by Hanisch, Franz-Georg; Green, Brian N.; Bateman, Robert; Peter-Katalinic, Jasna

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 268 KB
• Volume: 33
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199804)33:4<358::aid-jms642>3.0.co;2-3

✦ Synopsis

The potential of electrospray mass spectrometry (ESMS) for the sequencing of glycopeptides was evaluated using quadrupole time-of-Ñight (QTOF) technology in the MS/MS mode. The location of O-glycosylation sites was possible in the positive ion (+ ) mode by detection of prominent y-and b-fragment ions from the underivatized TAP25-2 [ T1APPAHGVT9S10APDT14RPAPGS20T21APPA ] , an overlapping sequence of MUC1 tandem repeats which had been glycosylated in vitro by two GalNAc residues in the positions T9 and T21. The high mass resolution and accuracy of QTOF-(+ )ESMS allowed reliable structural assignments. The reduced complexity of the fragment spectra and the higher signal-to-noise ratio render QTOF-(+ )ESMS an alternative mass spectrometric approach to the identiÐcation of O-glycosylation sites when compared with sequencing by post-source decay matrix-assisted laser desorption/ionization MS. Diagnostic ions from the N-terminus in the b-series o †ered direct evidence, which was supported by indirect evidence from the C-terminus ions of the y-series. The higher glycosylated fragments were mainly observed as multiply ionized species. 1998 John Wiley & Sons, GalNAc 2 -substituted ( Ltd.