Biomaterial Database

Factor XI activation in a revised model of blood coagulation. 1991

D Gailani, and G J Broze

Department of Medicine, Jewish Hospital, Washington University Medical Center, St. Louis, MO 63110.

Coagulation factor XI is activated in vitro by factor XIIa in the presence of high molecular weight kininogen (HMWK) and a negatively charged surface. Factor XII deficiency is not associated with bleeding, which suggests that another mechanism for factor XI activation exists in vivo. A revised model of coagulation is proposed in which factor XI is activated by thrombin. In the absence of cofactors, thrombin is more effective (kcat/Km = 1.6 x 10(5)) than factor XIIa (1.7 x 10(4)) in activating factor XI. Dextran sulfate enhances activation of factor XI by thrombin 2000-fold; part of this effect is due to autoactivation of factor XI by activated factor XI.

UI	MeSH Term	Description	Entries
D007704	Kininogens	Endogenous peptides present in most body fluids. Certain enzymes convert them to active KININS which are involved in inflammation, blood clotting, complement reactions, etc. Kininogens belong to the cystatin superfamily. They are cysteine proteinase inhibitors. HIGH-MOLECULAR-WEIGHT KININOGEN; (HMWK); is split by plasma kallikrein to produce BRADYKININ. LOW-MOLECULAR-WEIGHT KININOGEN; (LMWK); is split by tissue kallikrein to produce KALLIDIN.	Cystatins, Kininogen,Kininogen,Prekinins,Prokinins,T-Kininogen,Thiostatin,Kininogen Cystatins,T Kininogen
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D011761	Pyrrolidonecarboxylic Acid	A cyclized derivative of L-GLUTAMIC ACID. Elevated blood levels may be associated with problems of GLUTAMINE or GLUTATHIONE metabolism.	5-Oxoproline,Pidolic Acid,Pyroglutamic Acid,5-Ketoproline,5-Oxopyrrolidine-2-Carboxylic Acid,Magnesium Pidolate,Pyroglutamate,Pidolate, Magnesium
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
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
D002863	Chromogenic Compounds	Colorless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into colored compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. Synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens).	Chromogenic Compound,Chromogenic Substrate,Chromogenic Substrates,Compound, Chromogenic,Compounds, Chromogenic,Substrate, Chromogenic,Substrates, Chromogenic
D005172	Factor XI	Stable blood coagulation factor involved in the intrinsic pathway. The activated form XIa activates factor IX to IXa. Deficiency of factor XI is often called hemophilia C.	Coagulation Factor XI,Plasma Thromboplastin Antecedent,Blood Coagulation Factor XI,Factor 11,Factor Eleven,Antecedent, Plasma Thromboplastin,Factor XI, Coagulation,Thromboplastin Antecedent, Plasma
D006487	Hemostasis	The process which spontaneously arrests the flow of BLOOD from vessels carrying blood under pressure. It is accomplished by contraction of the vessels, adhesion and aggregation of formed blood elements (eg. ERYTHROCYTE AGGREGATION), and the process of BLOOD COAGULATION.	Hemostases