Linked Life Data

19150337

Source:http://linkedlifedata.com/resource/pubmed/id/19150337

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-2-6
pubmed:abstractText
Platelet Factor 4 (PF4) prevents inhibition of blood coagulation proteases by heparin via formation of a putative enzyme-PF4 complex. To investigate the contribution of the latter, the activity of factor Xa (fXa) was determined in chromogenic assays measuring hydrolysis of a peptide substrate S2765 or cleavage of the macromolecular substrate prothrombin in the activating complex, prothrombinase. Upon preincubation with fXa and heparin, PF4 at about 250 nM decreased the k(cat) of S2765 hydrolysis about fivefold and that of prothrombin activation about 25-fold. In the presence of saturating fVa, inhibition of fXa by PF4 was abolished, while in the presence of limiting fVa, PF4 altered the interaction of fXa with fVa. Interestingly, high concentrations of PF4 restored fXa activity toward S2765 and prothrombin, indicating a dual effect of PF4 on fXa activities. These findings suggest that PF4 in the presence of heparin is an allosteric effector of the prothrombinase complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1090-2104
pubmed:author
pubmed:issnType
Electronic
pubmed:day
20
pubmed:volume
379
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1072-5
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Dual effect of Platelet Factor 4 on the activities of Factor Xa.
pubmed:affiliation
University College London, Haemostasis Research Unit, Department of Haematology, 51, Chenies Mews, London WC1E 6HX, United Kingdom. m.fiore@ucl.ac.uk
pubmed:publicationType
Journal Article