Linked Life Data

12683946

Source:http://linkedlifedata.com/resource/pubmed/id/12683946

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-4-9
pubmed:abstractText
Metabolism of the human chorionic gonadotrophin (hCG)- and LHbeta-subunits (hCGbeta, LHbeta) terminates with the urinary excretion of core fragment (hCGbetacf, LHbetacf) molecules that retain antigenic shape and constituent N-linked carbohydrate moieties. We have previously demonstrated the resolved mass spectra of hCGbetacf, from which the carbohydrate moieties present at two N-linked glycosylation sites were identified. LHbetacf was subjected to the same mass spectrometric analysis. As LHbeta shares 82% homology with hCGbeta but possesses only one glycosylation consensus site a simpler spectral fingerprint of LHbetacf glycoforms was expected. LHbetacf was reduced with dithiothreitol and analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Glycoforms were predicted by subtracting the peptide mass from the m/z values of the observed peaks and then sequentially subtracting the masses of the monosaccharide residues of hCGbeta N-linked carbohydrates reported in the literature. The mass spectra of LHbetacf revealed a broad single peak ranging from m/z 8700 to 10 700. Following reduction, this peak was replaced by a set of partially resolved peaks between m/z 4130 and 5205 corresponding to glycosylated forms of the peptide LHbeta6-40. A peak at m/z 4252.2 corresponded to the non-glycosylated peptide LHbeta55-93. Remaining peaks indicated that the pooled sample comprised a wide set of glycoforms, contained LHbetacf with two N-linked carbohydrate moieties and indicated evidence of further glycosylation due to amino acid substitution in polymorphic variants. This is evidence that a single nucleotide polymorphism alters the post-translational modification of a protein and hence its structural phenotype.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0952-5041
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
239-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Identification of post-translational modifications resulting from LHbeta polymorphisms by matrix-assisted laser desorption time-of-flight mass spectrometric analysis of pituitary LHbeta core fragment.
pubmed:affiliation
Department of Obstetrics and Gynaecology, St Bartholomew's and the Royal London School of Medicine and Dentistry, West Smithfield, London EC1A 7BE, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't