Primary intermediate in the reaction of oxygen with fully reduced cytochrome c oxidase.

Han, Sim-Hee; Ching, Yuan-Chin; Rousseau, Denis L.

doi:10.1073/pnas.87.7.2491

Cited by 102 publications

(89 citation statements)

References 26 publications

(24 reference statements)

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“…1B), to 608 nm while losing some intensity. The peaks at 430 and 606 nm in the absolute spectra are characteristic for the oxoferryl state (Fe 4ϩ ϭO) of heme a 3 , and the P-state, specifically P R (32)(33)(34)(35)(36)(37)(38). The spectra obtained after 220 and 355 s indicated a small blue shift of the ␣-band from 608 to 603-604 nm without a change in the Soret region (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The oxygen-reduction cycle of CcO has been studied by a great variety of kinetic techniques such as the flow-flash method monitored by UV-visible spectroscopy (10 -13, 23, 28 -31) or resonance Raman scattering (32)(33)(34)(35)(36)(37)(38). Collectively these studies have led to a general understanding of the catalytic mechanism in terms of oxygen chemistry, electron transfer, and proton translocation.…”

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confidence: 99%

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Kinetic Resolution of a Tryptophan-radical Intermediate in the Reaction Cycle of Paracoccus denitrificans Cytochrome c Oxidase

Wiertz

Richter

Ludwig

et al. 2007

Journal of Biological Chemistry

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The catalytic mechanism, electron transfer coupled to proton pumping, of heme-copper oxidases is not yet fully understood. Microsecond freeze-hyperquenching single turnover experiments were carried out with fully reduced cytochrome aa 3 reacting with O 2 between 83 s and 6 ms. Trapped intermediates were analyzed by low temperature UV-visible, X-band, and Q-band EPR spectroscopy, enabling determination of the oxidation-reduction kinetics of Cu A , heme a, heme a 3 , and of a recently detected tryptophan radical (Wiertz, The superfamily of heme-copper oxidases comprises the cytochrome oxidases, which catalyze the reduction of molecular oxygen to water and the NO reductases that catalyze the reduction of NO to N 2 O (1-6). Cytochrome oxidases (CcOs) 2 are the final electron acceptors in the respiratory chains of bacteria, archaea, and mitochondria. Cytochrome aa 3 from Paracoccus denitrificans, is a Type A oxidase based on the structure of its D-and K-proton pathways (7, 8). The reduction of oxygen (Reaction 1) generates a proton electrochemical gradient across the cytoplasmic membrane. Four protons are used for the formation of water, and four are pumped across the membrane according to,Fwhere H C ϩ are protons taken up from the cytoplasm and H P ϩ protons are those ejected to the periplasm (9 -13). The crystal structures of cytochrome aa 3 from bovine heart mitochondria, P. denitrificans, and Rhodobacter sphaeroides have been solved previously (8, 14 -18). P. denitrificans cytochrome aa 3 is a four-subunit membrane complex. Subunit one harbors heme a and the heme a 3 -Cu B binuclear reaction center where reduction of oxygen takes place. Subunit two contains the docking site for cytochrome c (19,20) and the Cu A mixedvalence binuclear center with two copper atoms separated by 2.5 Å (21). Electrons from cytochrome c enter CcO at the Cu A site and are further transferred via heme a to heme a 3 and Cu B . Protons from the cytoplasm enter the enzyme via the D-or K-proton pathways (10 -13, 22, 23). These pathways connect the aqueous cytoplasmic phase with the conserved Glu-278 3 in the interior of the enzyme (D-pathway) or with the binuclear center (K-pathway). The proton exit route to the periplasm is less well defined. Water is expelled to the periplasm via the Mg 2ϩ or Mn 2ϩ bound at the interface of subunits .The oxygen-reduction cycle of CcO has been studied by a great variety of kinetic techniques such as the flow-flash method monitored by UV-visible spectroscopy (10 -13, 23, * This work was supported by the Foundation for Fundamental Research on Matter (FOM) (Grant FOM-D26) and the Deutsche Forschungsgemeinschaft (Grant SFB 472). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. □ S The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. S1-S3 and Table S1. 1 To whom correspondence should be addr...

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Kinetic Resolution of a Tryptophan-radical Intermediate in the Reaction Cycle of Paracoccus denitrificans Cytochrome c Oxidase

Wiertz

Richter

Ludwig

et al. 2007

Journal of Biological Chemistry

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“…Reaction of the two-electron-reduced enzyme with dioxygen leads to the formation of a ferrous-oxy species known as intermediate A (Compound A). This species has been observed in flow-flash resonance Raman experiments using both fully reduced and mixed valence cytochrome oxidase (52,53,90,126,127). It is characterized by a peak at 571 cm −1 in the resonance Raman spectrum and a very small shift in the Soret band in the absorption difference spectrum (versus reduced enzyme).…”

Section: Reaction Of the Enzyme With Dioxygenmentioning

confidence: 97%

Structures and Proton-Pumping Strategies of Mitochondrial Respiratory Enzymes

Schultz

Chan

2001

Annu. Rev. Biophys. Biomol. Struct.

246

177

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Key Words crystal structures, free energy transduction, mitochondrion, redox linkage, respiratory electron transport chain s Abstract Enzymes of the mitochondrial respiratory chain serve as proton pumps, using the energy made available from electron transfer reactions to transport protons across the inner mitochondrial membrane and create an electrochemical gradient used for the production of ATP. The ATP synthase enzyme is reversible and can also serve as a proton pump by coupling ATP hydrolysis to proton translocation. Each of the respiratory enzymes uses a different strategy for performing proton pumping. In this work, the strategies are described and the structural bases for the action of these proteins are discussed in light of recent crystal structures of several respiratory enzymes. The mechanisms and efficiency of proton translocation are also analyzed in terms of the thermodynamics of the substrate transformations catalyzed by these enzymes. CONTENTS

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“…Before the introduction of the water molecule, the coordination geometry of O 2 must be similar to the geometry of the O 2 -bound forms of hemoglobins and myoglobins, as has been suggested by data acquired from time-resolved resonance Raman spectroscopy (2)(3)(4). The stability of the Fe 2 ).…”

Section: Discussionmentioning

confidence: 99%

Bovine cytochrome c oxidase structures enable O ₂ reduction with minimization of reactive oxygens and provide a proton-pumping gate

Muramoto

Ohta

Shinzawa‐Itoh

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

145

212

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The O 2 reduction site of cytochrome c oxidase (CcO), comprising iron (Fe a 3 ) and copper (Cu B ) ions, is probed by x-ray structural analyses of CO, NO, and CN - derivatives to investigate the mechanism of the complete reduction of O 2 . Formation of the derivative contributes to the trigonal planar coordination of and displaces one of its three coordinated imidazole groups while a water molecule becomes hydrogen bonded to both the CN - ligand and the hydroxyl group of Tyr244. When O 2 is bound to , it is negatively polarized ( ), and expected to induce the same structural change induced by CN - . This structural change allows to receive three electron equivalents nonsequentially from , , and Tyr-OH, providing complete reduction of O 2 with minimization of production of active oxygen species. The proton-pumping pathway of bovine CcO comprises a hydrogen-bond network and a water channel which extend to the positive and negative side surfaces, respectively. Protons transferred through the water channel are pumped through the hydrogen-bond network electrostatically with positive charge created at the Fe a center by electron donation to the O 2 reduction site. Binding of CO or NO to induces significant narrowing of a section of the water channel near the hydrogen-bond network junction, which prevents access of water molecules to the network. In a similar manner, O 2 binding to is expected to prevent access of water molecules to the hydrogen-bond network. This blocks proton back-leak from the network and provides an efficient gate for proton-pumping.

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Primary intermediate in the reaction of oxygen with fully reduced cytochrome c oxidase.

Cited by 102 publications

References 26 publications

Kinetic Resolution of a Tryptophan-radical Intermediate in the Reaction Cycle of Paracoccus denitrificans Cytochrome c Oxidase

Kinetic Resolution of a Tryptophan-radical Intermediate in the Reaction Cycle of Paracoccus denitrificans Cytochrome c Oxidase

Structures and Proton-Pumping Strategies of Mitochondrial Respiratory Enzymes

Bovine cytochrome c oxidase structures enable O ₂ reduction with minimization of reactive oxygens and provide a proton-pumping gate

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Primary intermediate in the reaction of oxygen with fully reduced cytochrome c oxidase.

Cited by 102 publications

References 26 publications

Kinetic Resolution of a Tryptophan-radical Intermediate in the Reaction Cycle of Paracoccus denitrificans Cytochrome c Oxidase

Kinetic Resolution of a Tryptophan-radical Intermediate in the Reaction Cycle of Paracoccus denitrificans Cytochrome c Oxidase

Structures and Proton-Pumping Strategies of Mitochondrial Respiratory Enzymes

Bovine cytochrome c oxidase structures enable O 2 reduction with minimization of reactive oxygens and provide a proton-pumping gate

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Bovine cytochrome c oxidase structures enable O ₂ reduction with minimization of reactive oxygens and provide a proton-pumping gate