Biomaterial Database

Activation of factor IX by factor XIa--a spectrophotometric assay for factor IX in human plasma. 1982

G Tans, and T Janssen-Claessen, and G van Dieijen, and H C Hemker, and J Rosing

The activation of Factor IX by partially purified Factor XIa was followed by active site titration, gelelectrophoresis and by a spectrophotometric assay. The assay is based on the finding that the rate of Factor X activation in the presence of phospholipid and Ca2+ is linear in time and proportional to the amount of Factor IXa present and can be determined with the chromogenic substrate S2222. Conditions were found that allowed complete activation of Factor IX in human plasma by Factor XIa. The amount of Factor IXa present in the plasma sample can be determined with the spectrophotometric assay and is proportional with the amount of plasma present. In plasma from patients receiving vitamin-K antagonists reduced Factor IX activity is found with the spectrophotometric assay and the new assay method may be useful in monitoring oral anticoagulant therapy.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D001780	Blood Coagulation Tests	Laboratory tests for evaluating the individual's clotting mechanism.	Coagulation Tests, Blood,Tests, Blood Coagulation,Blood Coagulation Test,Coagulation Test, Blood,Test, Blood Coagulation
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
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
D005164	Factor IX	Storage-stable blood coagulation factor acting in the intrinsic pathway of blood coagulation. Its activated form, IXa, forms a complex with factor VIII and calcium on platelet factor 3 to activate factor X to Xa. Deficiency of factor IX results in HEMOPHILIA B (Christmas Disease).	Autoprothrombin II,Christmas Factor,Coagulation Factor IX,Plasma Thromboplastin Component,Blood Coagulation Factor IX,Factor 9,Factor IX Complex,Factor IX Fraction,Factor Nine,Factor IX, Coagulation
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
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man