Reaction: Selective cleavage of ArgThr and ArgIle in prothrombin to form thrombin and two inactive fragments
Other name(s): taipan activator; Oxyuranus scutellatus prothrombin-activating proteinase
Comments: From the venom of the Taipan snake (Oxyuranus scutellatus). Converts prothrombin to thrombin. Specificity is similar to that of Factor Xa (EC 188.8.131.52). However, unlike Factor Xa this enzyme can cleave its target in the absence of coagulation Factor Va. Activity is potentiated by phospholipid and Ca2+ which binds via γ-carboxyglutamic acid residues. Similar enzymes are known from the venom of other Australian elapid snakes, including Pseudonaja textilis textilis. Oxyuranus microlepidotus and Demansia nuchalis affinis.
Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, CAS registry number: 93389-45-8
1. Walker, F.J., Owen, W.G. and Esmon, C.T. Characterization of the prothrombin activator from the venom of Oxyuranus scutellatus scutellatus (taipan venom). Biochemistry 19 (1980) 1020-1023. [PMID: 6986908]
2. Speijer, H., Govers-Reimslag, J.W., Zwaal, R.F. and Rosing, J. Prothrombin activation by an activator from the venom of Oxyuranus scutellatus (taipan snake). J. Biol. Chem. 261 (1986) 13258-13267. [PMID: 3531198]