中文摘要：

作者从自行分离的高度耐盐菌Arthrobacter pascens DMDC12中分离提取超氧化物歧化酶（SOD），粗酶液经硫酸铵分级沉淀、DEAE-Sapharose FF及Source 15Q柱层析，获得了电泳纯的SOD。其亚基相对分子质量23300，比活力为2183U／mg，纯化倍数为53，回收率51％。根据SOD同功酶对抑制剂氯仿：乙醇和H2O2的敏感性，判断其为Mn—SOD。金属离子Mg^2＋、Zn^2＋、Ba^2＋、Cu^2＋对酶产生一定抑制，Fe^2＋对酶产生显著的抑制，0．5mmol／L的Mn抖对酶有激活作用，进一步证实该酶为Mn—SOD。该酶在45℃以下、PH5～9范围内显示较好的稳定性。相关研究进一步验证了极端微生物是Mn-SOD的重要酶源。

英文摘要：

Superoxide dismutase was considered as a metalloenzyme with the ability of resisting oxydative stress. SOD has extensive function, such as antiradiation, antiaging and anticancer. In this manuscript, a kind of SOD from the strain of Arthrobacter pascens DMDC12 was purified. The crude enzyme was purified by ammonium sulfate fractional pricipitation, DEAE Sepharose FF chromatography and Source 15Q chromatography. The purified enzyme showed homogeneity and subunit molecular weight of 23. 3Kda on electrophoresis of sodium dodecyl sulfate polyacylamide slab gel. The purification resulted in 53-fold purification with a 51% recovery of total activity. The specific activity of purified SOD was reached 2183U/mg. The inhibit test of H2O2 and chlorofrom-ethanol to SOD showed that the purified enzyme was Mn-SOD. Strong inhibition by Fe^2＋ and weak inhibition by Mg^2＋, Zn^2＋, Ba^2＋ and Cu^2＋ to the SOD were observed, while Mn^2＋ of 0. 5mol/L provided slight stimulation. The Mn-SOD was further proved. The purified SOD showed good stability under 45℃ and over the pH range 5.0 to 9.0. These results also suggested that extremophiles could be as good resource of Mn-SOD.