Linked Life Data

8256861

Source:http://linkedlifedata.com/resource/pubmed/id/8256861

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
1994-1-13
pubmed:abstractText
Electrospray ionization mass spectrometry utilizing a single quadrupole on line with reversed-phase HPLC (LC/MS) enables the characterization of glycoproteins in a relatively short period of time. In this approach the protein is digested with a suitable protease and the peptides are separated by reversed-phase HPLC and detected by electrospray ionization mass spectrometry. The glycopeptides are initially observed as a cluster of negatively sloping ions in a contour plot of data from the LC/MS run (m/z vs retention time) or as a characteristics series of masses at different elution times. The search for a particular glycopeptide is based on previously known carbohydrate structures and on consensus glycosylation sites. Further structural information is obtainable with glycosidase digestion and LC/MS analysis. The mass shifts following glycosidase digestion allow further confirmation of the structure. This approach identifies the site of attachment of two hybrid glycoforms to the T11 tryptic peptide in a reversed-phase tryptic map of recombinant tissue plasminogen activator (rt-PA). Use of selected ion extraction of the LC/MS data files allows one to graphically describe the elution order of closely related glycopeptides. The potential of LC/MS for the characterization of small amounts of unknown glycoproteins is shown by the study of an rt-PA mutant. A new potential site for glycosylation is created by site directed mutagenesis of wild type rt-PA with replacement of a threonine residue with asparagine at residue 103. An examination of a tryptic map shows that the mutant contains two new complex carbohydrate chains. The introduction of the new asparagine proximal to asparagine 117 changes this native high-mannose site in rt-PA to a complex-type glycosylation. This method allows rapid identification of carbohydrate containing peptides and yields useful structural information on microgram amounts of material.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0003-2700
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2953-62
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Identification of carbohydrate structures in glycoprotein peptide maps by the use of LC/MS with selected ion extraction with special reference to tissue plasminogen activator and a glycosylation variant produced by site directed mutagenesis.
pubmed:affiliation
Department of Medicinal and Analytical Chemistry, Genentech Inc., South San Francisco, California 94080.
pubmed:publicationType
Journal Article