ハブ毒からの Thrombin-like enzyme の分離

抄録

It has been not reported whether thrombin-like enzyme was contained or not in venom of Habu (Trimeresurus flavoviridis) which have the strongest toxic effect in the case of the Habu bite. The present study was taken to clarify the existence of thrombin-like enzyme in venom of Habu. As a starting material, the lyophilized crude venom of T. flavoviridis was used and ammonium sulphate fractionation gel filtration using sephadex G-150 and affinity chromatography using arginine-sepharose were procedured in order to separate and purify a thrombin-like enzyme from crude venom. Time required to convert from the purified rabbit fibrinogen to fibrin by the addition of this enzyme was determined as clotting time using Hema tracer. The enzyme was purified a 137-fold increase in specific activity and purified preparation showed a single band on SDS-PAGE. Molecular weight of this enzyme was 65, 000-70, 000 daltons by means of SDS-PAGE and gel filtration and isoelectric point of this enzyme was pH 4.5-5.5. Any enzymatic properties were studied on the differences between this enzyme and bovine thrombin and this enzyme could coagulate only the rabbit plasma.
From these results, it was concluded that thrombin-like enzyme entirely different from bovine thrombin, existed in T. flavoviridis venom.