Enhanced sensitivity of Streptomyces seoulensis to menadione by superfluous lipoamide dehydrogenase

FEBS Letters

Youn, Hwan¹  Kang, Sa-Ouk¹ 

[1] Laboratory of Biophysics, Department of Microbiology, College of Natural Sciences, and Research Center for Molecular Microbiology, Seoul National University, Seoul 151-742, South Korea

关键词: Menadione;    Lipoamide dehydrogenase;    Redox cycling;    Superoxide radical anion;    Streptomyces seoulensis;   

DOI  :  10.1016/S0014-5793(00)01437-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Lipoamide dehydrogenase from Streptomyces seoulensis could facilitate menadione-mediated cytochrome c reduction, which was mostly inhibited by superoxide dismutase, indicating the obvious involvement of superoxide radical anion. In this reaction, the production of superoxide radical anion occurred via a menadione semiquinone radical anion. When exposed to menadione, lipoamide dehydrogenase-overexpressing cells showed a much lower survival rate with a concomitant decrease of intracellular protein thiol than the wild-type strain. These results suggest that lipoamide dehydrogenase is a facilitating agent in the redox cycling of quinone compounds in vivo as well as in vitro and could inevitably increase the potential toxicity of the compounds.

【 授权许可】

Unknown