Cytochrome oxidase, ligands and electrons

Brunori, Maurizio; Giuffrè, Alessandro; Sarti, Paolo

doi:10.1016/j.jinorgbio.2004.10.011

Cited by 120 publications

(88 citation statements)

References 128 publications

(167 reference statements)

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“…5.4 10 4 M −1 s −1 in the W303 strain (Fig. 1B), in good agreement with that found with purified CcOx (23,34,35). In addition we studied the dependence of the amplitude of the flash-induced absorption change at 445 nm on the energy of the flash.…”

Section: Resultssupporting

confidence: 86%

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Questioning the functional relevance of mitochondrial supercomplexes by time-resolved analysis of the respiratory chain

Trouillard

Meunier

Rappaport

2011

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

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Mitochondria are the powerhouses of eukaryotic cells as they feed metabolism with its major substrate. Oxidative-phosphorylation relies on the generation, by an electron/proton transfer chain, of an electrochemical transmembrane potential utilized to synthesize ATP. Although these fundamental principles are not a matter of debate, the emerging picture of the respiratory chain diverges from the linear and fluid scheme. Indeed, a growing number of pieces of evidence point to membrane compartments that possibly restrict the diffusion of electron carriers, and to supramolecular assembly of various complexes within various kinds of supercomplexes that modulate the thermodynamic and kinetic properties of the components of the chain. Here, we describe a method that allows the unprecedented time-resolved study of the respiratory chain in intact cells that is aimed at assessing these hypotheses. We show that, in yeast, cytochrome c is not trapped within supercomplexes and encounters no particular restriction to its diffusion which questions the functional relevance of these supramolecular edifices.bioenergetics | electon transfer | respiration | compartmentalization

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Section: Resultssupporting

confidence: 86%

“…Bimolecular rate constants of 6.8 10 7 M −1 s −1 and 9.5 10 7 M −1 s −1 in the W303 and BY strains, respectively were obtained (Fig. 3C), in good agreement with previously published data (23,34,40,41). .…”

Section: Light-activation Of the Respiratory Chain In The Presence Ofsupporting

confidence: 91%

Questioning the functional relevance of mitochondrial supercomplexes by time-resolved analysis of the respiratory chain

Trouillard

Meunier

Rappaport

2011

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

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“…The only rate-limiting stage in the turnover appears to be the internal electron transfer between heme a and the [heme a 3 -Cu B ] pair. The reduction of the [a 3 -Cu B ] binuclear heme site by the reduced heme a occurs in millisecond time scale (14). One can speculate that irradiation intensifies exactly this electron transfer stage within the enzyme.…”

Section: The Possible Photoacceptor In Mammalian Cells For Visible Anmentioning

confidence: 97%

Multiple roles of cytochrome c oxidase in mammalian cells under action of red and IR‐A radiation

2010

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SummaryThis article reviews the current knowledge in photobiology and photomedicine about the influence of monochromatic, quasimonochromatic, and bread-band radiation of red-to-near infrared (IR-A) part on solar spectrum upon mammalian cells and human skin. The role of cytochrome c oxidase as the photoacceptor and photosignal transducer is underlined and its photosensitivity at certain circumstances is discussed. The role of ATP as a critical signaling molecule is discussed.

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“…As in other heme proteins, the protein environment at the active site is responsible for fine tuning the heme affinity for the various competitive ligands. In contrast to O 2 , CO forms a stable complex with the enzyme and has thus been used in numerous experiments aimed at elucidating ligand binding and transfer in CcO (21,22). CO binds to Cu B before binding to the heme Fe (23) as well as after photodissociation from the heme Fe (24).…”

mentioning

confidence: 99%

Direct observation of ligand transfer and bond formation in cytochrome c oxidase by using mid-infrared chirped-pulse upconversion

Treuffet

Kubarych

Lambry

et al. 2007

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

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We have implemented the recently demonstrated technique of chirped-pulse upconversion of midinfrared femtosecond pulses into the visible in a visible pump-midinfrared probe experiment for high-resolution, high-sensitivity measurements over a broad spectral range. We have succeeded in time-resolving the CO ligand transfer process from the heme Fe to the neighboring CuB atom in the bimetallic active site of mammalian cytochrome c oxidase, which was known to proceed in <1 ps, using the full CO vibrational signature of Fe-CO bond breaking and CuB-CO bond formation. Our differential transmission results show a delayed onset of the appearance of the CuB-bound species (200 fs), followed by a 450-fs exponential rise. Trajectories calculated by using moleculardynamics simulations with a Morse potential for the CuB-C interaction display a similar behavior. Both experimental and calculated data strongly suggest a ballistic contribution to the transfer process.

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Cytochrome oxidase, ligands and electrons

Cited by 120 publications

References 128 publications

Questioning the functional relevance of mitochondrial supercomplexes by time-resolved analysis of the respiratory chain

Questioning the functional relevance of mitochondrial supercomplexes by time-resolved analysis of the respiratory chain

Multiple roles of cytochrome c oxidase in mammalian cells under action of red and IR‐A radiation

Direct observation of ligand transfer and bond formation in cytochrome c oxidase by using mid-infrared chirped-pulse upconversion

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