title: [Proteolysis of prothrombin by beta/gamma thrombin].
abstract: beta/gamma-thrombin containing 25% of beta-form and 75% of gamma-form was obtained from alpha-thrombin by limited trypsin proteolysis. As compared to the parent alpha-thrombin, these preparations preserved less than 0.02% of fibrinogen-clotting activity, the entire esterase activity and 27% of the amidolytic activity toward N-benzoyl-Phe-Val-Arg-p-nitroanilide. Like alpha-thrombin, beta/gamma-thrombin splits prothrombin to prethrombin I (Mr 58000) and fragment I of prothrombin (Mr 25000) possessing antithrombin activity. Kinetics of prothrombin hydrolysis was studied by different concentrations of enzymes. It was shown that alpha-form is more specific than beta/gamma-form that preserved approximately 5% of prothrombinolytic activity of alpha-thrombin. It is emphasized that beta/gamma-form devoid of clotting activity retains regulatory functions.
mesh_terms: D000581:Amidohydrolases; D001777:Blood Coagulation; D004950:Esterases; D006868:Hydrolysis; D007700:Kinetics; D011516:Prothrombin; D013917:Thrombin
chemical_list: D011516:Prothrombin; D004950:Esterases; D013917:Thrombin; D000581:Amidohydrolases
vernacular_title: Proteoliz protrombina beta/gamma-trombin.