金属螯合亲和层析法纯化玉米SOD及其酶学性质的研究

Studies on Purification of SOD from Maize by MCAC and its Enzymatic Properties

利用硫酸铵分级沉淀、凝胶过滤初步分离了玉米SOD,利用金属螯合亲和层析纯化了SOD.电泳后活性染色与蛋白染色均得到3个条带,比活为8597,纯化倍数为307,回收率为29.4%,达到了电泳纯.结果表明玉米SOD亚基的分子量为16 000,最大紫外吸收在260 nm处,该酶在pH值7～9、80℃以下稳定,玉米SOD对KCN和H2O2敏感,对邻苯三酚的Vmax为49.50 mmol/min、Km为0.163 4 mmol/L.

Superoxide dismutase （SOD） was preliminarily separated from maize by precipitation with ammonium sulfate and gelfiltration and then purified by metal chelate affinity chromatography （MCAC）. After electrophoresis, three color trips were obtained from both active chromating and protein chromating with specific activity of 8591, purification factor of 307 and recovery rate of 29.4%, and the electrophoretic pure was reached. The results showed that the molecular weight of SOD subunit was 16 KD and the ultraviolet ab sorption peak was at 260 nm; SOD was stable under pH 7～9 and below 80℃, sensitive to KCN and H2O2 , and its Vmax in and Km in pyrogallol were 49.50 mmol/min and 0.1634 mmol/L respectively.