摘要
本文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。比活为8597,纯化倍数为307,回收率为29.4%,电泳后活性染色与蛋白染色均得到3个条带,达到了电泳纯。针对SOD稳定性较差的缺陷,进行了PEG修饰SOD研究。修饰率46%,SOD活性保持度为81%。修饰后的玉米SOD的温度稳定性、pH稳定性均明显提高,与天然SOD相比,PEG-SOD的胰蛋白酶酶切耐受性明显增强。结果表明,PEG修饰玉米SOD是可行的,PEG是一种较好的SOD化学修饰剂。
The crude enzyme was obtained from maize by precipitation with ammonium sulfate and sephadexG- 100.Then SOD was purified by metal chelating chromatography（MCAC）. The specific activity was 8591with a purification factor of 307. The purified enzyme was found to be homogeneous with a recovery rate of 29.4%. In order to enhance the stability of SOD, SOD was modified with PEG. It was shown in the result that the modification rate was 46% and the recovery of SOD was 81%.The stability of PEG-SOD against heat, pH and trypsin degradation were increased significantly. It can be conclude that using PEG to modify SOD of maize is feasible and PEG is a kind of good chemical modification reagent.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2007年第2期70-73,共4页
Food Science
关键词
SOD
金属螯合亲和层析
纯化
聚乙二醇
化学修饰
superoxide dismutase（SOD）
metal chelating chromatography（MCAC）
purification
polyethylene glycol （PEG）
chemical modification
