Linked Life Data

1331708

Source:http://linkedlifedata.com/resource/pubmed/id/1331708

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1992-12-8
pubmed:abstractText
The assembly and function of the prothrombinase complex on the bovine and human platelet membrane is mediated through binding interactions in which factor Va bound to the platelet surface forms at least part of the "receptor" for factor Xa in a 1:1 stoichiometric complex. A model depicting these binding interactions is shown in Fig. 12. Data from our laboratory indicate that the prothrombinase catalyst assembles in an analogous manner on the surface of monocytes, lymphocytes, neutrophils, and well-defined phospholipid vesicles employed in model systems. The 74,000-Da subunit of factor Va, component E, which mediates the binding of factor Va to either bovine platelets, human monocytes, or phospholipid vesicles, is shown binding to the cell membrane through its putative "receptor." The 94,000-Da subunit of factor Va, component D, is associated with the membrane surface through its metal ion-dependent interaction with component E. Factor Va forms at least part of the receptor that mediates the binding of factor Xa to an appropriate membrane surface, because component E has been shown to contribute significantly to the interaction of factor Xa with either the platelet, monocyte, or vesicle membrane surface. Our data do not preclude the possibility that component D contributes to the binding of factor Xa and the function of the prothrombinase complex. Component D appears to be important for several reasons. Cleavage of component D by activated protein C results in the complete loss of factor Va cofactor activity. An interaction between factor Xa and component D is implied from the observation that factor Xa protects factor Va from activated protein C inactivation. Furthermore, the binding of factor Xa to platelet-bound factor Va results in the time-dependent cleavage of components D and D'. Because component D is not required absolutely for prothrombinase complex assembly, we would speculate that it may be important in mediating prothrombin binding (depicted as a three-domain molecule) and increasing the catalytic efficiency of the enzymatic complex.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0076-6879
pubmed:author
pubmed:issnType
Print
pubmed:volume
215
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
329-60
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Platelet factor Xa receptor.
pubmed:affiliation
Department of Biochemistry, University of Vermont College of Medicine, Burlington 05405.
pubmed:publicationType
Journal Article