γ-射线对抗辐射菌抗氧化酶活性的影响

The Effects of γ-rays on the Activity of Anti-oxidative Enzymes in Deinococcus Radiodurans

目的 研究不同剂量60 Coγ 射线作用后抗辐射菌中超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)活性的变化 ,与不同剂量60 Coγ 射线照射后大肠杆菌中这两种酶活性变化相比较 ,探讨SOD、CAT与抗辐射菌辐射抗性的相关性。方法 应用单胺氧化法和钼酸铵法分别测定SOD和CAT活性 ,用Bradford法测定蛋白质含量。结果 未受照射时抗辐射菌的CAT和SOD活性大于大肠杆菌中这两种酶的活性 (P <0 .0 1) ;当受到不同剂量的γ 射线作用后 ,抗辐射菌中这两种酶的活性随着剂量的增加出现先升高后降低的趋势 ,而大肠杆菌受照后这两种酶活性几乎均呈下降趋势。并且受照后抗辐射菌中这两种酶的活性均高于大肠杆菌 (P <0 .0 1)。结论 抗辐射菌的抗氧化能力高于大肠杆菌。

Objective To discuss the relationship between activities of SOD,CAT and radio resistance of Deinococcus radiodurans, Deinococcus radiodurans and Escherichia coli JM109 strain irradiated with different dose of 60 Co γ radiation,and the activities of superoxide dismutase (SOD) and catalase (CAT) of them were compared. Methods The activities of SOD and CAT were determined by Monoamine oxidized method and Ammonium molybdenum acid method respectively. The concentration of protein were determined by Bradford method. Results The activity of SOD and CAT in Deinococcus radiodurans was higher than that in Escherichia coli JM109( P <0.01). After irradiated, the activity of SOD and CAT in Deinococcus radiodurans ascended first, then descended after rea ching the peak. But they almost always descended in JM109 when it was irradiated. After irradiated, the activity of these two enzymes in Deinococcus radiodurans was much higher than that in Escherichia coli JM109( P <0.01). Conclusion Deinococcus radiodurans′ resistance to oxidative stress is higher than Escherichia coli′s.