【摘要】 经过 75 %硫酸铵沉淀、SephadexG 75凝胶过滤层析、DEAESephadexA 2 5离子交换层析、Benzamide Sepharose 4B亲和层析 ,从杭州虻 (Tabanushongchowensis )腹部匀浆液中分离纯化出分子量约为 36 5kD的纤溶酶THFE。经纤维蛋白平板测定表明 ,THFE既具有纤溶酶作用 ,又具有激活纤溶酶原的作用。THFE能分解纤溶酶原激活剂的生色底物———ChromozymUK及S 2 2 88,对纤溶酶的生色底物ChromozymP的活性较高 ,合成生色底物测定结果与纤维蛋白平板测定结果一致。THFE具有类胰蛋白酶活性 ,专一水解精氨酸形成的酰胺键 (或肽键 ) ,几乎不具有胰凝乳蛋白酶活性。抑制剂对THFE活性的抑制也证明了上述测定结果更多还原

【Abstract】 After ammonium sulphate precipitation, Sephadex G 75 gel filtration, DEAE Sephadex A 25 ion exchange chromatography and Benzamide Sepharose 4B affinity chromatography, the fibrinolytic enzyme(THFE) was separated from the extract of T.hongchowensis Liu abdomen in the buffer. It appeared as a single band corresponding to molecular weight(MW) of approximately 36.5kD on SDS PAGE. On the fibrin plate and plasminogen free fibrin plate which had been heated at 85℃ for 30 minutes to eliminate plasminogen, THFE showed the same fibrinolytic activity. The result indicated that THFE might contain both a fibrinolytic enzyme which degraded fibrin directly, and a plasminogen activator which degraded fibrin by activating plasminogen. THFE showed stronger activity against Chromozym UK and S 2288(chromogenic substrate for plasminogen activator).The results which THFE degraded chromogenic substrates might indicate that THFE possessed trypsin like activity,and specific degraded amide bond or arginine formed peptide bond, but had litter chymotrypsin activity. THFE was almost inhibited powerfully by antipain, soybean trypsin inhibitor and soybean Bowman Birk inhibitor. However, chicken egg white trypsin inhibitor was least effective as inhibitor of THFE. THFE activity could be inhibited half by PMSF, leupeptin, antitrypsin and TLCK.更多还原