黄鳝超氧化物歧化酶的纯化和部分性质研究

黄鳝超氧化物歧化酶粗酶液，经过正丁醇脱脂，丙酮分级沉淀，DEAE-琼脂糖离子交换层析和Sephacryl S-200凝胶过滤，从黄鳝中分离纯化获得铁超氧化物歧化酶(Fe-SOD)，并对其性质进行研究，最终该酶的比活力为1500U／mg，提纯倍数为368．5．回收率为24．7％．该酶对KCN不敏感．而对H2O2敏感，对热较稳定，对酸碱有较强的耐受性，抗胃蛋白酶的破坏，聚丙烯酰胺凝胶电泳和等电点聚焦电泳结果表明：纯化酶蛋白呈一条带，酶分子量约为85kD，亚基分子量约为16．5kD，等电点为7．15。

Purification and Some Properties of Superoxide Dismutase from Monopterus albus Zuiew

Superoxide dismustase was purified from Monopterus albus by grading precipitation with acetone, DEAE-Sepharose chromatography and Sephacry1 S-200 gel filtration. And some of its characters were analyzed. The results showed that the specific activity of the enzyme was 1 500 units per mg protein. The purification factor was 368.5. The yield was 24.7%. The enzyme was not sensitive to KCN, but it was sensitive to H_2O_2. The enzyme was stable in heat condition. It was found that the enzyme showed greater resistance to acid, alkali and pepsin degradation. It exhibits one absorption maximum in the ultraviolet at 280 nm. Its protein band showed only one by SDS-PAGE and IEF. The enzyme showed that the molecular weight was 85 000 daltons as determined with gel filtration on Sephacry1 S-200. The subunits was 16 500 daltons as estimated with SDS-PAGE. The isoelectric point of SOD was 7.15.