PprI和RecX蛋白对耐辐射奇球菌抗氧化作用的影响

利用基因突变、化学发光法和酶活性分析研究了耐辐射奇球菌中与辐射抗性密切相关的基因pprI(Dr0167)和recX(Dr1310)突变对菌体活性氧清除作用的影响,分析了其对抗氧化酶活性的调控功能。实验结果表明,缺失pprI的突变株对活性氧自由基氧化异常敏感,过氧化氢酶和超氧化物歧化酶活性显著降低。与之相反,RecX对菌体活性氧清除作用表现为一种“负”的影响,即缺失recX的突变株对活性氧自由基的清除能力反而增强了,过氧化氢酶和超氧化物歧化酶的酶活性明显增加。表明这两个基因与抗氧化系统的调控有关。为进一步研究该菌的抗氧化机制提供了一些思路。

Effects of Pprl and RecX on antioxidant activity of Deinococcus radiodumns

Effects of mutations of PprI(Dr0167) and RecX(Dr1310),which are relative to radioresistance,on reactive oxygen species scavenging activities in Deinococcus radiodurans were investigated using gene mutation,chemiluminescence measurement and enzyme activity analysis.Their possible regulating functions on the activities of antioxidant enzymes was evaluated.Results show that mutant that lacks PprI is remarkably sensitive to reactive oxygen species and its enzyme activities of catalase and superoxide dismutase decrease significantly.On the other hand,RecX has a "negative " effect on reactive oxygen species scavenging activities of this bacterium,i.e.,mutation of recX enhances the scavenging activities on reactive oxygen species,and the enzyme activities of catalase and superoxide dismutase in mutant that lacks RecX are significantly increased.These results indicate that these two genes are relative to the regulation of antioxidant system of this bacterium.It presents some idea to the further investigation on the antioxidant mechanism of this bacterium.