过氧化氢酶和DNA修复系统在大肠杆菌抵御过氧化氢过程中的独特作用。

The distinct role of catalase and DNA repair systems in protection against hydrogen peroxide in Escherichia coli.

作者信息

Yonei S, Yokota R, Sato Y

出版信息

Biochem Biophys Res Commun. 1987 Mar 13;143(2):638-44. doi: 10.1016/0006-291x(87)91401-x.

Abstract

The katEkatG mutant of E. coli, UM1, had no assayable catalase activities in the extract and showed increased (about 20 fold) sensitivity to killing by H2O2 when compared with its parental strain CSH7. The mutant strain was able to reactivate H2O2-damaged lambda phage. On the other hand, recA and polA mutants were also highly sensitive to H2O2, but they had normal level of catalase activities. RecA derivatives of UM1 were much more sensitive to H2O2 than UM1 and recA strains. The induction of umu operon occurred in UM1 at lower (1/10-1/20) doses of H2O2 than in CSH7. From the results it is concluded that the lethal effect of H2O2 is due to DNA damage induced by it and that catalase and DNA repair systems have a distinct role in protection against H2O2 in E. coli.

摘要

大肠杆菌UM1的katEkatG突变体提取物中没有可检测到的过氧化氢酶活性，与亲本菌株CSH7相比，对H2O2杀伤的敏感性增加（约20倍）。该突变菌株能够重新激活H2O2损伤的λ噬菌体。另一方面，recA和polA突变体对H2O2也高度敏感，但它们的过氧化氢酶活性水平正常。UM1的RecA衍生物对H2O2的敏感性比UM1和recA菌株高得多。与CSH7相比，UM1在较低（1/10 - 1/20）剂量的H2O2作用下会发生umu操纵子的诱导。从结果可以得出结论，H2O2的致死作用是由于其诱导的DNA损伤，而过氧化氢酶和DNA修复系统在大肠杆菌中对H2O2的保护作用中具有不同的作用。