Assignment of Saccharide Identities through Analysis of Oxonium Ion Fragmentation Profiles in LC MS/MS of Glycopeptides

作者：Halim Adnan; Westerlind Ulrika; Pett Christian; Schorlemer Manuel; Ruetschi Ulla; Brinkmalm Gunnar; Sihlbom Carina; Lengqvist Johan; Larson Goran; Nilsson Jonas^*

来源：Journal of Proteome Research, 2014, 13(12): 6024-6032.

DOI：10.1021/pr500898r

• glycoproteomics
• oxonium ion
• LC-MS/MS
• glycopeptide
• O-glycosylation

Protein glycosylation plays critical roles in the regulation of diverse biological processes, and determination of glycan structure-function relationships is important to better understand these events. However, characterization of glycan and glycopeptide structural isomers remains challenging and often relies on biosynthetic pathways being conserved. In glycoproteomic analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS) using collision-induced dissociation (CID), saccharide oxonium ions containing N-acetylhexosamine (HexNAc) residues are prominent. Through analysis of beam-type CID spectra and ion trap CID spectra of synthetic and natively derived N- and O-glycopeptides, we found that the fragmentation patterns of oxonium ions characteristically differ between glycopeptides terminally substituted with GalNAca1-O-, GlcNAc beta 1-O-, Gal beta 3GalNAca1-O-, Gal beta 4GlcNAc beta-O-, and Gal beta 3GlcNAc beta-O- structures. The difference in the oxonium ion fragmentation profiles of such glycopeptides may thus be used to distinguish among these glycan structures and could be of importance in LC-MS/MS-based glycoproteomic studies.

• 出版日期2014-12