Linked Life Data

18000604

Source:http://linkedlifedata.com/resource/pubmed/id/18000604

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-11-16
pubmed:abstractText
Previous studies of factor (F)Va inactivation on human umbilical vein endothelial cells have shown that alpha-thrombin cleaves the heavy chain near the COOH-terminus to produce a M(r) 97,000 fragment containing the NH(2)-terminal portion of the heavy chain and a M(r) 8,000 peptide containing the rest of the molecule. The alpha-thrombin cleavage appeared to occur between amino acid residues 586 and 654 of FV. This region contains a consensus sequence for alpha-thrombin cleavage located at residues 640-644 (S-S-P-R-S). To test the hypothesis that alpha-thrombin cleaves the FVa heavy chain at Arg(643) and to evaluate the functional importance of this cleavage for FVa inactivation, site-directed mutagenesis was used to create recombinant FV molecules with mutations R(643) --> Q (FV(R643Q)) and R(643) --> A (FV(R643A)). All recombinant molecules were purified to homogeneity and assayed for activity following extended activation with alpha-thrombin. Under similar experimental conditions, appearance of the M(r) 97,000 heavy chain fragment in the plasma and wild-type FVa molecules correlated with partial loss of cofactor activity, while following extended incubation of FV(R643Q) and FV(R643A) with alpha-thrombin no cleavage of the heavy chain at Arg(643) was detected and no presence of the M(r) 97,000 heavy-chain fragment was noticed. Further, no loss in cofactor activity was observed using these mutant recombinant FVa molecules. Our data demonstrate that cleavage of FVa at Arg(643) by alpha-thrombin results in a partially inactive cofactor molecule and provides for an activated protein C (APC)-independent anticoagulant effect of alpha-thrombin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0340-6245
pubmed:author
pubmed:issnType
Print
pubmed:volume
98
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
998-1006
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Identification of an inactivating cleavage site for alpha-thrombin on the heavy chain of factor Va.
pubmed:affiliation
Department of Chemistry, Cleveland State University, 2351 Euclid Avenue, Science and Research Center SR 370, Cleveland, Ohio 44115, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural