【摘要】 经 (NH4 ) 2 SO4 分级沉淀、SephadexG 75凝胶过滤和DEAE 5 2柱层析将苏云金杆菌 4.0 718菌株的超氧化物岐化酶 (SOD)纯化到均一程度 ,酶比活力达 688.0U/mg ,酶得率为 47.9% 该酶经KCN ,H2 O2 ,氯仿 乙醇抑制实验 ,金属元素含量测定和紫外可见吸收光谱测定 ,表明是Fe SOD 经反相高效液相色谱和电喷雾质谱联合分析等方法 ,测得酶分子量为 3 9.4861× 10 6 ,由两个相同亚基组成 ,N 末端氨基酸为丙氨酸更多还原

【Abstract】 A superoxide dismutase from Bacillus thuringiensis strain 4.0718 has been purified to homogeneity by ammonium sulfate fractionation, Sephadex G-75 gel filtration and DEAE-cellulose-exchange chromatograph. The specific activity of the purified enzyme is 688.0 U/mg protein and the yield of the purified enzyme is 47.9%. The enzyme is an iron superoxide dismutase as assayed by its sensitivity to inhibitor: KCN, H 2O 2, CH 3CH 2OH-CHCl 3 and other methods: metal elements measure and ultraviolet-visible spectroscopy. The enzyme has a molecular weight of 39.486 1×10 6 with conjoint analysis of reversed-phase high-performance liquid chromatography and electrospray ionzation mass spectrometry. The enzyme contains two equally sized subunits.The N-terminal amino acid of the enzyme is alanine as tested by DNS-Cl.更多还原