Cytochrome c oxidase rapidly metabolises nitric oxide to nitrite

FEBS Letters

Sharpe, Martyn A¹  Wilson, Mike T¹  Cooper, Chris E¹  Rosquist, Aasa¹  Torres, Jaume¹ 

[1] Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK

关键词: Cytochrome c oxidase;    Nitrite;    Nitric oxide;    Inhibition;    Metabolism;    Cytochrome c;   

DOI  :  10.1016/S0014-5793(00)01682-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Previous studies have shown that the addition of nitric oxide to cytochrome c oxidase rapidly generates spectral changes compatible with the formation of nitrite at the binuclear haem:copper centre. Here we directly demonstrate nitrite release following nitric oxide addition to the enzyme. The nitrite complex is kinetically inactive and the off rate for nitrite was found to be slow (0.024 min⁻¹). However, the presence of reductants enhances the off rate and enables cytochrome oxidase to catalyse the rapid oxidation of nitric oxide to nitrite free in solution. This may play a major role in the mitochondrial metabolism of nitric oxide.

【 授权许可】

Unknown