Bovine Factor Xa
Factor Xa is prepared by activating purified Factor X with the Factor X activator isolated from Russell’s viper venom. Cleavage occurs at the Arg51-Ile52 bond and releases an activation peptide. Factor Xa is purified from the activation mixture by chromatography over benzamidine-Sepharose. Purity is determined by SDS-PAGE analysis and activity is measured in a Factor Xa clotting assay and/or chromogenic substrate assay.