Identification of the copper-zinc superoxide dismutase activity in Mycoplasma hyopneumoniae
Identification of the copper-zinc superoxide dismutase activity in Mycoplasma hyopneumoniae
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DOI：
10.1016/s0378-1135(99)00170-4
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发表时间：
2000-05-11
影响因子：
3.3
通讯作者：
Lai, SS
中科院分区：
文献类型：
--
作者：
Chen, JR;Weng, CN;Lai, SS
铜锌超氧化物歧化酶（Cu/ZnSOD）是一种广泛存在于真核生物和多种革兰氏阴性菌中的抗氧自由基的关键酶。猪肺炎支原体（M.猪肺炎支原体肺炎的主要病原菌--猪肺炎支原体（猪肺炎支原体），由于牛Cu/ZnSOD多克隆抗体与M.来自全细胞蛋白的猪肺炎铜/锌超氧化物歧化酶。SDS-PAGE原位活性染色结果表明，M.还原型SOD分子量约为17kDa。用KCN和H_2O_2抑制酶的活性，证实了酶活性中心存在Cu和Zn离子。SDS-和天然聚丙烯酰胺凝胶上的小球藻Cu/ZnSOD被2 mM KCN完全抑制，并且凝胶显示粗提物中没有含铁SOD（FeSOD）或含锰SOD（MnSOD）。M.猪肺炎克雷伯菌Cu/ZnSOD粗提物的活性为70单位/mg蛋白质，5mM KCN抑制55%，40mM H_2O_2灭活56%。这种酶是生长阶段依赖性的，并证明在早期的日志阶段显着更高的生产。田间分离物中Cu/ZnSOD活性的表达水平也不同。综上所述，Cu/ZnSOD在M.首次鉴定出了猪肺炎支原体。(C)2000 Elsevier Science B.V.保留所有权利。
Copper-zinc superoxide dismutase (Cu/ZnSOD), a key enzyme in defense against toxic oxygen-free radicals, is widespread in eukaryotes and several species of gram-negative bacteria. The presence of this enzyme in Mycoplasma hyopneumoniae (M. hyopneumoniae), the primary pathogen of mycoplasmal pneumonia in pigs, was examined since the polyclonal antibody against bovine Cu/ZnSOD was dominantly cross-reactive with the M. hyopneumoniae Cu/ZnSOD from whole cellular proteins. In situ activity staining on SDS-PAGE showed that the molecular mass of M. hyopneumoniae Cu/ZnSOD in reducing form was approximate to 17 kDa. The presence of Cu and Zn ions at the active site of the enzyme was confirmed on the basis of inhibition by KCN and by H2O2 The activity of M. hyopneumoniae Cu/ZnSOD on both SDS- and native-polyacrylamide gels was completely inhibited by 2 mM KCN and the gels showed no iron-containing SOD (FeSOD) or manganese-containing SOD (MnSOD) in the crude extracts. The activity of M. hyopneumoniae Cu/ZnSOD in crude extract was 70 units/mg protein and was 55% inhibited by 5 mM KCN and 56% inactivated by 40 mM H2O2. This enzyme was growth-stage dependent and evidenced markedly higher production during the early log phase. Different expression levels of Cu/ZnSOD activity in field isolates were also detected. Taken together, the presence of Cu/ZnSOD in M. hyopneumoniae was identified for the first time. (C) 2000 Elsevier Science B.V. All rights reserved.