Biomaterial Database

Initiation of the extrinsic pathway of blood coagulation: evidence for the tissue factor dependent autoactivation of human coagulation factor VII. 1991

T Nakagaki, and D C Foster, and K L Berkner, and W Kisiel

Department of Pathology, University of New Mexico School of Medicine, Albuquerque 87131.

Previous studies demonstrated proteolytic activation of human blood coagulation factor VII by an unidentified protease following complex formation with tissue factor expressed on the surface of a human bladder carcinoma cell line (J82). In the present study, an active-site mutant human factor VII cDNA (Ser344----Ala) has been constructed, subcloned, and expressed in baby hamster kidney cells. Mutant factor VII was purified to homogeneity in a single step from serum-free culture supernatants by immunoaffinity column chromatography. Mutant factor VII was fully carboxylated, possessed no apparent clotting activity, and was indistinguishable from plasma factor VII by SDS-PAGE. Cell binding studies indicated that mutant factor VII bound to J82 tissue factor with essentially the same affinity as plasma factor VII and was cleaved by factor Xa at the same rate as plasma factor VII. In contrast to radiolabeled single-chain plasma factor VII that was progressively converted to two-chain factor VIIa on J82 monolayers, mutant factor VII was not cleaved following complex formation with J82 tissue factor. Incubation of radiolabeled mutant factor VII with J82 cells in the presence of recombinant factor VIIa resulted in the time-dependent and tissue factor dependent conversion of single-chain mutant factor VII to two-chain mutant factor VIIa. Plasma levels of antithrombin III had no discernible effect on the factor VIIa catalyzed activation of factor VII on J82 cell-surface tissue factor but completely blocked this reaction catalyzed by factor Xa. These results are consistent with an autocatalytic mechanism of factor VII activation following complex formation with cell-surface tissue factor, which may play an important role in the initiation of extrinsic coagulation in normal hemostasis.

UI	MeSH Term	Description	Entries
D001749	Urinary Bladder Neoplasms	Tumors or cancer of the URINARY BLADDER.	Bladder Cancer,Bladder Neoplasms,Cancer of Bladder,Bladder Tumors,Cancer of the Bladder,Malignant Tumor of Urinary Bladder,Neoplasms, Bladder,Urinary Bladder Cancer,Bladder Cancers,Bladder Neoplasm,Bladder Tumor,Cancer, Bladder,Cancer, Urinary Bladder,Neoplasm, Bladder,Neoplasm, Urinary Bladder,Tumor, Bladder,Tumors, Bladder,Urinary Bladder Neoplasm
D001777	Blood Coagulation	The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.	Blood Clotting,Coagulation, Blood,Blood Clottings,Clotting, Blood
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D005167	Factor VII	Heat- and storage-stable plasma protein that is activated by tissue thromboplastin to form factor VIIa in the extrinsic pathway of blood coagulation. The activated form then catalyzes the activation of factor X to factor Xa.	Coagulation Factor VII,Proconvertin,Stable Factor,Blood Coagulation Factor VII,Factor 7,Factor Seven,Factor VII, Coagulation
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000990	Antithrombin III	A plasma alpha 2 glycoprotein that accounts for the major antithrombin activity of normal plasma and also inhibits several other enzymes. It is a member of the serpin superfamily.	Heparin Cofactor I,Antithrombin III-Alpha,Atenativ,Heparin Co-Factor I,Kybernin,Serpin C1,Thrombate III,Antithrombin III Alpha,Antithrombin IIIAlpha,Cofactor I, Heparin,Heparin Co Factor I