一种食源性溶栓酶的分离纯化与部分酶学性质的研究

Purifaction and Characterizations of Nattokinase——A Kind of Food-Fibrinolytic Enzyme

目的对以豆渣为原料,接种纳豆菌的发酵物分离纯化和酶学性质研究。方法采用生理盐水浸提、（NH4）2SO4分级沉淀、Sephadex G-100凝胶层析等纯化步骤,得到层析纯的食源性溶栓酶-纳豆激酶,结果经聚丙烯酰胺凝胶电泳显示为二个组分。酶学性质研究表明,以酪蛋白为底物时,最适反应温度为60℃,最适反应pH为8.0,在pH7-9溶液中,37℃以下基本稳定。体外溶栓作用表明,纳豆激酶溶解纤维蛋白的方式主要是直接溶解,而不是纤溶酶原激活剂。

To study properties of nattokinase, a kind of food fibrinolytic enzyme was made by solid fermentation from soybean residue. It was extracted and purified by ammonium sulfate precipitation followed by Sephadex G - 100 chromatography. The purified enzyme contained two stainable subunits on the gel of SDS - PAGE. The optimum temperature and pH for hydrolysis of casein were 60℃ and 8.0, respectively. The enzyme was stable up to 37℃, within the pH range of 7 -9. The fibrinolysis activity was performed by degrading the fibrous protein directly, according to the experiment in vitro.