Identification of substituted sites on MUC5AC mucin motif peptides after enzymatic O‐glycosylation combining β‐elimination and fixed‐charge derivatization

Publisher Website
Google Scholar
Abstract
A strategy for determination of O‐glycosylation site(s) in glycopeptides has been developed using model compounds obtained by enzymatic glycosylation (by human GaNTase‐T2 isoform) on peptides derived from the human MUC5AC mucin tandem repeat motif. The β‐elimination‐addition reaction (using dimethylamine and concomitantly ethanethiol) on the formerly glycosylated sites through a Michael‐type condensation produced efficient deglycosylation with appropriate chemical modification. After N‐terminal derivatization by a phosphonium group, peptide sequencing was then carried out by nanospray tandem mass spectrometry experiments. The highly predictable fragmentation pathways of these fixed‐charge phosphonium derivatives enable straightforward recognition of glycosylation site(s) based on the mass increment of +44 Da for originally glycosylated threonine compared to the mass of fragments containing nonglycosylated residues. Copyright © 2001 John Wiley & Sons, Ltd.

This publication has 20 references indexed in Scilit: