摘要
经硫酸按沉淀、SephadexG－200凝胶过滤和DEAE－Sephacel层析3个步骤，将韭菜细胞溶质SOD纯化到均一程度。从500g叶片中得到2·4mm酶，酶比活力达13000U／mm蛋白。鉴定该酶是Cu·Zn—SOD。测得酶分子量约为30900道尔顿，亚基分子量约为15900道尔顿，N一末端氨基酸为丙氨酸。该酶在紫外与可见光区吸收峰分别在260urn和680urn。实验表明该酶热稳定性良好。
A superoxide dismutase from leek plasma has been purified to homogeneltyby ammonium sulfate fractionation, Sephadex G--200 gel filtration and DEAE--Sephacelchromatography. 2. 4 mg purified enzyme was obtained from b00 g leaves. The specificactivity of the purified enzyme is 13 000 U/mg protein. The enzyme is copper/zinc superoxide dlsmutase as assayed by its sensitivity to Inhibitors: KCN and H,O,. The molecularweight of the enzyme is about 30 900 dations as assayed by Sephadex G--200 gel filtration, that of the enzyme subunit is about I d 900 dations as tested by sodium dodecyl sulphate--polyacrylamlde gel electrophoresis. The N--terminal of the enzyme is alanine astested by dansyl chloride. The enzyme exhibits one absorption maximum in the ultraviolet at 260 urn and another in the VISible region at 680 urn. The result of experimentsshows that the enzyme has good heat stability.
出处
《武汉植物学研究》
CSCD
1998年第1期18-22,共5页
Journal of Wuhan Botanical Research
