超氧化物歧化酶分离-修饰耦合过程的研究

Study on the coupling procedure of SOD's purification and modification

以超氧化物歧化酶(SOD)为模板蛋白,研究其分离—修饰耦合工艺.即将SOD选择性地吸附在铜离子螯合葡聚糖凝胶层析柱上,先不经洗脱分离,直接用活化的聚乙二醇(PEG)5000对吸附的SOD进行化学修饰,再通过特异性洗脱分离获得PEG-SOD,使得SOD分离纯化和修饰过程同步完成.获得了一条SOD金属螯合层析分离—PEG化学修饰耦合工艺路线.获得的PEG-SOD比活9 055.1 U/mg,纯化倍数1.75倍,氨基修饰率42.3%,修饰前后活性保留87.1%.证明SOD的分离-修饰耦合工艺是可行的.

This article uses SOD as a template, to study its coupling procedure of purification and modification. SOD was mixed with Cu^2＋ chelating-sephadex G-75 without being washed immediately but modified by activated PEG5000 upon the solid-phase column, then washed specifically. The modification and purification of SOD completed synchronously. The specific activity of the obtained PEG-SOD is 9 055.1 U/mg, with a purification factor of 1.75, modified at 42.3% of its free amino groups, retained 87. 1% of enzymatic activity of native SOD. The results confirm that it is feasible to couple the purification and modification of SOD.