谷歌浏览器插件
订阅小程序
在清言上使用

Oxidase, superoxide dismutase, and hydrogen peroxide reductase activities of methanobactin from types I and II methanotrophs

Journal of Inorganic Biochemistry(2008)

引用 64|浏览25
暂无评分
摘要
Methanobactin (mb) is a copper-binding chromopeptide that appears to be involved in oxidation of methane by the membrane-associated or particulate methane monooxygenase (pMMO). To examine this potential physiological role, the redox and catalytic properties of mb from three different methanotrophs were examined in the absence and presence of O2. Metal free mb from the type II methanotroph Methylosinus trichosporium OB3b, but not from the type I methanotrophs Methylococcus capsulatus Bath or Methylomicrobium album BG8, were reduced by a variety of reductants, including NADH and duroquinol, and catalyzed the reduction of O2 to O2-. Copper-containing mb (Cu-mb) from all three methanotrophs showed several interesting properties, including reductase dependent oxidase activity, dismutation of O2- to H2O2, and the reductant dependent reduction of H2O2 to H2O. The superoxide dismutase-like and hydrogen peroxide reductase activities of Cu-mb were 4 and 1 order(s) of magnitude higher, respectively, than the observed oxidase activity. The results demonstrate that Cu-mb from all three methanotrophs are redox-active molecules and oxygen radical scavengers, with the capacity to detoxify both superoxide and hydrogen peroxide without the formation of the hydroxyl radicals associated with Fenton reactions. As previously observed with Cu-mb from Ms. trichosporium OB3b, Cu-mb from both type I methanotrophs stimulated pMMO activity. However, in contrast to previous studies using mb from Ms. trichosporium OB3b, pMMO activity was not inhibited by mb from the two type I methanotrophs at low copper to mb ratios.
更多
查看译文
关键词
Chalkophore,Copper-binding compound,Hydrogen peroxide reductase,Methanobactin,Membrane-associated methane monooxygenase,Methanotroph,Methylococcus capsulatus Bath,Methylomicrobium album BG8,Methylosinus trichosporium OB3b,Oxidase, siderophore,Oxygen radical scavenger, superoxide dismutase
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要