title: O-glycosylation sites identified from mucin core-1 type glycopeptides from human serum.
abstract: In this work O-linked glycopeptides bearing mucin core-1 type structures were enriched from human serum. Since about 70 % of the O-glycans in human serum bind to the plant lectin Jacalin, we tested a previously successful protocol that combined Jacalin affinity enrichment on the protein- and peptide-level with ERLIC chromatography as a further enrichment step in between, to eliminate the high background of unmodified peptides. In parallel, we developed a simpler and significantly faster new workflow that used two lectins sequentially: wheat germ agglutinin and then Jacalin. The first lectin provides general glycopeptide enrichment, while the second specifically enriches O-linked glycopeptides with Galβ1-3GalNAcα structures. Mass spectrometric analysis of enriched samples showed that the new sample preparation method is more selective and sensitive than the former. Altogether, 52 unique glycosylation sites in 20 proteins were identified in this study.
authors.affiliation: Laboratory of Proteomics Research, Biological Research Centre of the Hungarian Academy of Sciences, Institute of Biochemistry, Szeged, Hungary. darula.zsuzsanna@brc.mta.hu.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Darula
authors.affiliation: Laboratory of Proteomics Research, Biological Research Centre of the Hungarian Academy of Sciences, Institute of Biochemistry, Szeged, Hungary.
authors.forename: Farkas
authors.initials: F
authors.lastname: Sarnyai
authors.affiliation: Laboratory of Proteomics Research, Biological Research Centre of the Hungarian Academy of Sciences, Institute of Biochemistry, Szeged, Hungary.|Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, USA.
authors.forename: Katalin F
authors.initials: KF
authors.lastname: Medzihradszky
mesh_terms: D001665:Binding Sites; D006031:Glycosylation; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D018396:Mucin-1 / Q000097:blood / Q000737:chemistry* / Q000378:metabolism; D037121:Plant Lectins / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational
chemical_list: D018396:Mucin-1; D037121:Plant Lectins
keywords: Automated glycopeptide identification; ETD; HCD; Human serum; O-glycosylation