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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-10-27
pubmed:abstractText
The binding properties of the coagulation factor IX/factor X-binding anticoagulant protein (IX/X-bp) isolated from the venom of Trimeresurus flavoviridis (habu snake) were investigated with an enzyme-linked immunosorbent assay. The half-maximal binding and maximal binding of IX/X-bp to both factors IX and X were observed at concentrations of Ca2+ ions of 0.4 mM and 1 mM, respectively. Concentration of IX/X-bp at half-maximal binding to solid-phase bovine factor IX and solid-phase bovine factor X were 0.4 +/- 0.1 nM and 1.1 +/- 0.4 nM, respectively, in the presence of 1 mM Ca2+ ions. The kinetics of binding activity of IX/X-bp to bovine factors IXa and Xa and to human factors IX and X resembled those of the binding to bovine factors IX and X. IX/X-bp did not bind to solid-phase coagulation factors other than factor IX/IXa and factor X/Xa, for example, prothrombin, factor VII, protein C, and protein Z, under the conditions of the experiment. To localize the binding sites of IX/X-bp on the coagulation factors, the ability of IX/X-bp to bind to various fragments derived from factors IX and X was examined. The binding of IX/X-bp to solid-phase factor IX was inhibited by a peptide containing the 4-carboxyglutamic acid (Gla) domain derived from factor IXa beta' (residues 1-42) in the liquid phase, but the binding was not inhibited by Gla-domainless factor IXa beta'. Half-maximal binding of IX/X-bp to solid-phase Gla-domain peptide of factor IX occurred at 9.2 +/- 1.9 nM. Factor X was partially reduced and the S-carboxymethylated light and heavy chains of factor X were prepared. IX/X-bp bound to the S-carboxymethylated light chain of factor X but not to the heavy chain. The binding of IX/X-bp to solid-phase factor X was inhibited by the Gla-domain peptide of factor X (residues 1-44) but not by Gla-domainless factor X. IX/X-bp bound to PCGFX, a recombinant human protein C whose Gla-domain region (residues 1-43) had been replaced by residues 1-43 of human factor X. The affinity of binding was about one tenth of that to intact human factor X. IX/X-bp was unable to bind at all to human protein C. These data indicate that IX/X-bp is a protein that binds to the Gla-domain regions of factors IX and X in the presence of Ca2+ ions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
224
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
703-8
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Binding properties of the coagulation factor IX/factor X-binding protein isolated from the venom of Trimeresurus flavoviridis.
pubmed:affiliation
Department of Biochemistry, Meiji College of Pharmacy, Tokyo, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't