A possible role of reduced cytochrome c oxidase in the metabolism of nitric oxide (NO) has been examined with amperometric and stopped-flow photometric techniques. Reduced purified cytochrome c oxidase and mitochondria showed no catalytic reaction with NO under anaerobic conditions within more than 30 minutes. Only fast binding of NO to the reduced enzyme in a 1:1 stoichiometric ratio was observed. The NO binding rate was strongly decreased in the presence of 1 mM cyanide. These data indicate that, contrary to previous proposals, cytochrome c oxidase in the absence of oxygen does not contribute to physiological NO metabolism I.F.2.78
Cytochrome c oxidase does not catalyze the anaerobic reduction of NO / Gottfried, Stubauer; Giuffre', Alessandro; Brunori, Maurizio; Sarti, Paolo. - In: BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS. - ISSN 0006-291X. - 245:2(1998), pp. 459-465. [10.1006/bbrc.1998.8457]
Cytochrome c oxidase does not catalyze the anaerobic reduction of NO
GIUFFRE', ALESSANDRO;BRUNORI, Maurizio;SARTI, Paolo
1998
Abstract
A possible role of reduced cytochrome c oxidase in the metabolism of nitric oxide (NO) has been examined with amperometric and stopped-flow photometric techniques. Reduced purified cytochrome c oxidase and mitochondria showed no catalytic reaction with NO under anaerobic conditions within more than 30 minutes. Only fast binding of NO to the reduced enzyme in a 1:1 stoichiometric ratio was observed. The NO binding rate was strongly decreased in the presence of 1 mM cyanide. These data indicate that, contrary to previous proposals, cytochrome c oxidase in the absence of oxygen does not contribute to physiological NO metabolism I.F.2.78I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
