Site-specific characterisation of densely O-glycosylated mucin-type peptides using electron transfer dissociation ESI-MS/MS

Author(s)
Thaysen-Andersen, Morten
Wilkinson, Brendan
Payne, Richard J
Packer, Nicolle H
Publication Date
2011
Abstract
Site-specific characterisation of mucin-type O-linked glycosylation is an analytical challenge due to glycan heterogeneity, lack of glycosylation site consensus sequence and high density of occupied glycosylation sites. Here, we report the use of electron transfer dissociation (ETD) for the site-specific characterisation of densely glycosylated mucin type O-linked glycopeptides using ESI-IT-MS/MS. Synthetic glycopeptides from the human mucin-1 (MUC-1) tandem repeat region containing a range of O-linked, tumour associated carbohydrate antigens, namely Tn, T and sialyl T, with different glycosylation site occupancies and an increasing number of tandem repeats were studied. In addition, a glycopeptide from the anti-freeze glycoprotein of Antarctic and Arctic notothenoids, bearing four O-linked, per-acetylated T antigens was characterised. ETD MS/MS of infused or capillary LC-separated glycopeptides provided broad peptide sequence coverage (c/z·-type fragment ions) with intact glycans still attached to the Ser/Thr residues. Thus, the glycosylation sites were unambiguously determined, while simultaneously obtaining information about the attached glycan mass and peptide identity. Highly sialylated O-glycopeptides showed less efficient peptide fragmentation, but some sequence and glycosylation site information was still obtained. This study demonstrates the capabilities of ETD MS/MS for site-specific characterisation of mucin-type glyco peptides containing high-density O-linked glycan clusters, using accessible and relative low-resolution/low-mass accuracy IT MS instrumentation.
Citation
Electrophoresis, 32(24), p. 3536-3545
ISSN
1522-2683
0173-0835
Link
Publisher
Wiley-VCH Verlag GmbH & Co KGaA
Title
Site-specific characterisation of densely O-glycosylated mucin-type peptides using electron transfer dissociation ESI-MS/MS
Type of document
Journal Article
Entity Type
Publication

Files:

NameSizeformatDescriptionLink