双胸蚓纤溶酶的纯化及性质

 用硫酸铵分段盐析、超滤膜分级分离及DEAE-纤维素、Sephadex A-25和Sephadex G-50三种柱层析方法从双胸蚓组织的粗提取液中分离纯化出一种纤溶酶,分子量为29kD,由一条肽链组成。此晦具有强烈的溶解纤维蛋白的作用,对家兎实验性血凝块也具有明显的溶解作用。此酶的最适pH为8.0,在pH7.6～8.4之间活力相差不到2％;酶在PH4.7—11.0范围内稳定;酶作用的最适温度为57℃;此酶热稳定性较好,于25～50℃保温3小时,酶活力基本不变,60℃时,活力保留65％。金属离子Na~(+)、K~(+)、Mg~(2+)等可提高此酶的活力,而Hg~(2+)、Ca~(2+)等金属离子对此酶有不同程度的抑制作用。

Purification and Some Properties of Fibrinolytic Enzyme From Bimastos

A fibrinolytic enzyme was isolated and purified from the crude extract of the earthworm Bimastos tissue by the use of ammonium sulfate, ultrafiltration membrane fractionation and column chromatography successively with DEAE-cellulose, DEAE-Sephadex A-25 and Sephadex G-50 columns. The enzyme consists of a single chain with molecular weight 29000. It bas strong thrombolytic action on fibrin, the experimental thrombus of rabbit and the clots from human blood. Its optimum pH is 8.0, the difference of the enzyme activity is less than 2.0 percent in the pH range of 7.6 to 8.4. It is stable in the pH range of 4.7 to 11.0. The optimum temperature is 57℃, it has retained 65 percent of the original enzyme activity aftar incubation at 60℃ for 3 hours. The metal ions Hg2+, Ca2+ show some inhibition and Na+ , K+, Mg2+ can increase its activity.