华广虻溶纤活性蛋白(TAFP)的性质和对大鼠血液流变学的影响

华广虻溶纤活性蛋白 (TAFP)经血纤蛋白平板法和试管凝块法测定表明 ,TAFP只具有纤溶酶作用 ,不具有激活纤溶酶原的作用 .TAFP的最适 p H为 7.5,且在 p H为 6.0时最稳定 .蛋白水解酶抑制剂对 TAFP的抑制作用显示 :STI>antipain>SBBI>antitrypsin>TLCK>leupeptin>bacteracin>PMSF>TPCK,金属蛋白酶抑制剂 1 ,1 0 - phenanthroline对 TAFP没有抑制作用 .TAFP能显著的延长大鼠出血时间、抑制血小板聚集性 ;显著降低血浆中血纤蛋白原含量、全血粘度、血浆粘度、红细胞压积 ;减慢血沉速度

Properties of Fibrinolytic Protein from Tabanus amaenus Walker(TAFP) and Its Effects on Hemorheology in Rats *

In vitro , on fibrin plate and plasminogen free fibrin plate, the fibrinolytic protein from Tabanus amaenus Walker(TAFP)showed the same fibrinolytic activity as the mixture of TAFP and plasminogen indicating that TAFP was a fibrinolytic enzyme degrading fibrin directly, not a plasminogen activator, degrading fibrin via activating plasminogen. TAFP was found also to degrade fibrinogen. Its optimum pH was 7.5. Inhibition of TAFP activity by protease inhibitors showed: soybean trypsin inhibitor>antipain>soybean Bowman Birk inhibitor>antitrypsin>N P toluenesulfonyl L lysine chloromethyl ketone>leupeptin>bacteracin>phenylmethylsufonyl fluoride>N P toluenesulfonyl L phenylanine chloromethyl ketone, and 1, 10 phenanthroline had no inhibition of TAFP activity. It was most remarkable, versus control, that TAFP caused prolongation of bleeding time, inhibition of platelet aggregation, decrease of fibrinogen level in plasma, whole blood viscosity, plasma viscosity and erythrocyte sedimentation, thus reducing hemalocrit velocity in vivo .