The flavohaemoglobin (HMP) of Escherichia coli generates superoxide in vitro and causes oxidative stress in vivo

FEBS Letters

Poole, Robert K.¹  Ioannidis, Nicolaos¹  Membrillo-Hernández, Jorge¹ 

[1] Division of Life Sciences, King's College London, Campden Hill Road, London W8 7AH, UK

关键词: Hemoglobin;    Suporoxide;    Superoxide dismutase;    Flavohaemoglobin;    Integration host factor;    Transcription;    Escherichia coli;   

DOI  :  10.1016/0014-5793(96)00154-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Purified flavohaemoglobin (HMP) of Escherichia coli reduces Fe(III) in a superoxide dismuatase (SOD)-sensitive reaction, demonstrating superoxide anion generation during aerobic NADH oxidation. In vivo, sodA-lacZ fusion activity was increased 3-fold by introducing plasmid pPL341, containing the hmp gene, or by growth with paraquat. The effects were additive and SOXS-dependent. Thus HMP activity causes oxidative stress in vivo. Activities of sodA-lacZ and hmp-lacZ fusions were stimulated in a himA mutant, demonstrating repression of both promoters by integration host factor (IHF), but the effects of pPL341 on sodA-lacZ activity were not due to titration of IHF by the hmp promoter.

【 授权许可】

Unknown