Linked Life Data

9312074

Source:http://linkedlifedata.com/resource/pubmed/id/9312074

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
1997-10-22
pubmed:abstractText
Since there is no consensus sequence directing the initial GalNAc incorporation into mucin peptides, O-glycosylation sites are not reliably predictable. We have developed a mass spectrometric sequencing strategy that allows the identification of in vivo O-glycosylation sites on mucin-derived glycopeptides. Lactation-associated MUC1 was isolated from human milk and partially deglycosylated by trifluoromethanesulfonic acid to the level of core GalNAc residues. The product was fragmented by the Arg-C-specific endopeptidase clostripain to yield tandem repeat icosapeptides starting with the PAP motif. PAP20 glycopeptides were subjected to sequencing by post-source decay matrix-assisted laser desorption ionization mass spectrometry or by solid phase Edman degradation to localize the glycosylation sites. The masses of C- or N-terminal fragments registered for the mono- to pentasubstituted PAP20 indicated that GalNAc was linked to the peptide at Ser5,Thr6 (GSTA) and Thr14 (VTSA) but contrary to previous in vitro glycosylation studies also at Thr19 and Ser15 located within the PDTR or VTSA motifs, respectively. Quantitative data from solid phase Edman sequencing revealed no preferential glycosylation of the threonines. These discrepancies between in vivo and in vitro glycosylation patterns may be explained by assuming that O-glycosylation of adjacent peptide positions is a dynamically regulated process that depends on changes of the substrate qualities induced by glycosylation at vicinal sites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24780-93
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Localization of O-glycosylation sites on glycopeptide fragments from lactation-associated MUC1. All putative sites within the tandem repeat are glycosylation targets in vivo.
pubmed:affiliation
Institute of Biochemistry, Medical Faculty of the University, 50931 Cologne, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't