Escherichia coli expresses a copper- and zinc-containing superoxide dismutase.
Escherichia coli expresses a copper- and zinc-containing superoxide dismutase.
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DOI：
10.1016/s0021-9258(18)47248-1
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发表时间：
1994-10
期刊：
影响因子：
--
通讯作者：
Ludmil T. BenovS;Irwin Fridovichg
中科院分区：
文献类型：
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作者：
Ludmil T. BenovS;Irwin Fridovichg
大肠杆菌的突变体，不能产生锰或铁的含超氧化物歧化酶（SOD），被发现含有适度水平的SOD被判断为铜和锌的SOD的基础上的抑制氰化物和灭活由H2O2或二乙基二硫代氨基甲酸酯。此外，二乙基二硫代氨基甲酸酯失活的酶可以重新激活与铜（II），这重建的酶，像本地的酶，是不受EDTA和抑制氰化物。这种酶，此外，选择性地释放渗透压休克，保持与周质定位，它是强烈诱导有氧生长。该酶也存在于SOD感受态亲本菌株中。未能检测到它以前可以归因于其周质定位，热不稳定性，对pH值的敏感性，以及它的相对缺乏。现在，探索这种SOD缺乏所造成的表型后果将是有趣的。
A mutant of Escherichia coli, unable to produce manganese- or iron-containing superoxide dismutase (SOD), was found to contain modest levels of an SOD that was judged to be a copper- and zinc-containing SOD on the basis of inhibition by cyanide and inactivation by either H2O2 or diethyldithiocarbamate. Moreover, the diethyldithiocarbamate-inactivated enzyme could be reactivated with Cu(II), and this reconstituted enzyme, like the native enzyme, was unaffected by EDTA and was inhibited by cyanide. This enzyme was, furthermore, selectively released by osmotic shock, in keeping with a periplasmic localization, and it was strongly induced during aerobic growth. This enzyme was also present in the SOD-competent parental strain. Failure to detect it previously can be attributed to its periplasmic localization, thermal lability, sensitivity to pH, and to its relative paucity. It will now be interesting to explore the phenotypic consequences imposed by the absence of this SOD.