Reactions of nitric oxide with cytochrome c oxidase

Gary W Brudvig, Tom H. Stevens, Sunney I. Chan

Research output: Contribution to journalArticle

207 Citations (Scopus)

Abstract

The reactions of nitric oxide (NO) with both oxidized and reduced cytochrome c oxidase are reported. NMR and mass spectroscopy were utilized to determine the products of the reactions; EPR and optical spectroscopy were employed to determine the states of the enzyme produced in each of these reactions. It was found that the enzyme catalyzes the consecutive oxidation and reduction of NO. A different cycle was observed when NO was added to the reduced enzyme, to the oxidized enzyme, or to the oxidized enzyme in the presence of azide. It was possible to observe the state of the enzyme at several points in each of these three cycles by varying the concentration of NO. The reactions of NO all involved a one- or two-electron redox step and could be accounted for by the involvement of only cytochrome a3 and Cua3. On the basis of these results, a mechanism for the reduction of dioxygen by the enzyme is proposed in which cytochrome a3 functions to anchor dioxygen and intermediates while remaining in the ferrous state, whereas Cua3 functions to accept electrons from cytochrome a/Cua and transfer them to dioxygen.

Original languageEnglish
Pages (from-to)5275-5285
Number of pages11
JournalBiochemistry
Volume19
Issue number23
Publication statusPublished - 1980

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Electron Transport Complex IV
Nitric Oxide
Enzymes
Cytochromes a3
Electrons
Oxygen
Oxidation-Reduction
Cytochromes a
Azides
Anchors
Paramagnetic resonance
Mass Spectrometry
Spectrum Analysis
Magnetic Resonance Spectroscopy
Nuclear magnetic resonance
Spectroscopy
Oxidation

ASJC Scopus subject areas

  • Biochemistry

Cite this

Brudvig, G. W., Stevens, T. H., & Chan, S. I. (1980). Reactions of nitric oxide with cytochrome c oxidase. Biochemistry, 19(23), 5275-5285.

Reactions of nitric oxide with cytochrome c oxidase. / Brudvig, Gary W; Stevens, Tom H.; Chan, Sunney I.

In: Biochemistry, Vol. 19, No. 23, 1980, p. 5275-5285.

Research output: Contribution to journalArticle

Brudvig, GW, Stevens, TH & Chan, SI 1980, 'Reactions of nitric oxide with cytochrome c oxidase', Biochemistry, vol. 19, no. 23, pp. 5275-5285.
Brudvig GW, Stevens TH, Chan SI. Reactions of nitric oxide with cytochrome c oxidase. Biochemistry. 1980;19(23):5275-5285.
Brudvig, Gary W ; Stevens, Tom H. ; Chan, Sunney I. / Reactions of nitric oxide with cytochrome c oxidase. In: Biochemistry. 1980 ; Vol. 19, No. 23. pp. 5275-5285.
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