Separation of mammalian cytochrome c oxidase into 13 polypeptides by a sodium dodecyl sulfate-gel electrophoretic procedure

Kadenbach, Bernhard; Jarausch, Jochen; Hartmann, Renate; Merle, Peter

doi:10.1016/0003-2697(83)90586-9

Cited by 431 publications

(234 citation statements)

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“…Cardiolipin binding studies confirm the presence of two high-affinity and one or two lower-affinity binding sites (13). CcO, therefore, contains two types of CL binding sites: (1) two high-affinity sites that regulate electron transport and (2) one or two lower-affinity sites that stabilize subunits VIa and VIb and, therefore, CcO dimerization.…”

mentioning

confidence: 80%

Photolabeling of Cardiolipin Binding Subunits within Bovine Heart CytochromecOxidase

et al. 2005

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Subunits located near the cardiolipin binding sites of bovine heart cytochrome c oxidase (CcO) were identified by photolabeling with arylazido-cardiolipin analogues and detecting labeled subunits by reversed-phase HPLC and HPLC-electrospray ionization mass spectrometry. Two arylazidocontaining cardiolipin analogues were synthesized: (1) 2-SAND-gly-CL with a nitrophenylazido group attached to the polar headgroup of cardiolipin (CL) via a linker containing a cleavable disulfide; (2) 2′,2″-bis-(AzC 12 )-CL with two of the four fatty acid tails of cardiolipin replaced by 12-(N-4-azido-2-nitrophenyl) aminododecanoic acid. Both arylazido-CL derivatives were used to map the cardiolipin binding sites within two types of detergent-solubilized CcO: (1) intact 13-subunit CLcontaining CcO (three to four molecules of endogenous CL remain bound per CcO monomer); (2) 11-subunit CL-free CcO (subunits VIa and VIb are missing because they dissociate during CL removal). Upon the basis of these photolabeling studies, we conclude that (1) subunits VIIa, VIIc, and possibly VIII are located near the two high-affinity cardiolipin binding sites, which are present in either form of CcO, and (2) subunit VIa is located adjacent to the lower affinity cardiolipin binding site, which is only present in the 13-subunit form of CcO. These data are consistent with the recent CcO crystal structure in which one cardiolipin is located near subunit VIIa and a second is located near subunit VIa (PDB ID code 1V54 referenced in Tomitake, T. et al. (2003) Proc. Natl. Acad. Sci. U.S.A. 100, 15304−15309). However, we propose that a third cardiolipin is bound between subunits VIIa and VIIc near the entrance to the D-channel. Cardiolipin bound at this location could potentially function as a proton antenna to facilitate proton entry into the D-channel. If true, it would explain the CcO requirement of bound cardiolipin for full electron transport activity.Cardiolipin (diphosphatidylglycerol, CL 1 ) is a unique phospholipid found in membranes that couple electron transport to oxidative phosphorylation, for example, mitochondrial inner membrane and bacterial cytoplasmic membrane (2-4). In eukaryotes, CL is synthesized exclusively within the mitochondrion and is found only in the mitochondrial inner membrane. The structure of CL is quite different from other phospholipids. It contains three glycerols, two

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confidence: 80%

Photolabeling of Cardiolipin Binding Subunits within Bovine Heart CytochromecOxidase

et al. 2005

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“…The high-resolution gel electrophoresis system allows separation of mammalian COX into 13 subunits (23). The recently presented crystal structure of bovine heart cytochrome oxidase assigned all 13 subunits to the monomeric complex, each in equimolar amounts (24).…”

Section: Composition and Structure Of Eucaryotic Coxmentioning

confidence: 99%

“…The remaining subunits (IV, Va, Vb, VIa, VIb, VIc, VIIa, VIIb, VIIc, and VIII; nomenclature of ref. 23) are encoded by nuclear DNA and are imported into the mitochondria. In the crystal structure, the nuclear-encoded subunits are associated with the surface of the three core subunits, leaving some uncovered areas.…”

Section: Composition and Structure Of Eucaryotic Coxmentioning

confidence: 99%

“…Thereafter, Kadenbach and coworkers (23) hypothesized that ATP, which is exchangeable for ADP, interacts with the matrix part of the transmembrane subunit IV. The crystal structure of bovine heart COX (24) indicates close proximity between the matrix domain of subunit IV and the subunit Vb, thus rendering conformational interactions feasible, particularly during thyroid hormone or cAMP signaling (Table 2).…”

Section: Allosteric Inhibition Of Cox By High Internal Atp/adpmentioning

confidence: 99%

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Regulation of Cytochrome c Oxidase by Adenylic Nucleotides. Is Oxidative Phosphorylation Feedback Regulated by its End‐Products?

Beauvoit¹,

Rigoulet²

2001

IUBMB Life

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SummaryCytochrome c oxidase, which catalyzes an irreversible step of the respiratory chain, is one of the rate-controlling steps of oxidative phosphorylation on isolated mitochondria. The rate of electron transfer through the complex is primarily controlled by the associated thermodynamic forces, i.e., the span in redox potential between oxygen and cytochrome c and the protonmotive force. However, the electron ux also depends on the various kinetic effectors, including adenylic nucleotides. Although the number of binding sites for ATP and ADP on cytochrome oxidase is still a matter of debate, experiments performed on the solubilized and reconstituted enzyme provide strong functional evidence that the mammalian cytochrome c oxidase binds adenylic nucleotides on both sides of the inner membrane. These effects include modi cation in cytochrome c af nity, allosteric inhibition and changes in proton pumping ef ciency. Immunological studies have pointed out the role of subunit IV and that of an ATP-binding protein, subunit VIa, in these kinetic regulations. In yeast, the role of the nuclear-encoded subunits in assembly and regulation of the cytochrome c oxidase has been further substantiated by using gene-disruption analysis. Using a subunit VIa-null mutant, the consequences of the ATP regulation on oxidative phosphorylation have been further investigated on isolated mitochondria. Taken together, the data demonstrate that there are multiple regulating sites for ATP on the yeast cytochrome oxidase with respect to the location (matrix versus cytosolic side), kinetic effect (activation versus inhibition) and consequence on the ow-force relationships. The question is therefore raised as to the

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“…The detergent solubilized bovine heart oxidase consists of a dimer [7], wherein each monomer comprises thirteen nonidentical subunits [8]. The cytochrome oxidase from shark (Sphyma lewini) is isolated as a fully functional monomer [9].…”

Section: Introductionmentioning

confidence: 99%

A ¹H NMR study of bovine cytochrome oxidase

et al. 1989

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Separation of mammalian cytochrome c oxidase into 13 polypeptides by a sodium dodecyl sulfate-gel electrophoretic procedure

Cited by 431 publications

References 17 publications

Photolabeling of Cardiolipin Binding Subunits within Bovine Heart CytochromecOxidase

Photolabeling of Cardiolipin Binding Subunits within Bovine Heart CytochromecOxidase

Regulation of Cytochrome c Oxidase by Adenylic Nucleotides. Is Oxidative Phosphorylation Feedback Regulated by its End‐Products?

A ¹H NMR study of bovine cytochrome oxidase

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Separation of mammalian cytochrome c oxidase into 13 polypeptides by a sodium dodecyl sulfate-gel electrophoretic procedure

Cited by 431 publications

References 17 publications

Photolabeling of Cardiolipin Binding Subunits within Bovine Heart CytochromecOxidase

Photolabeling of Cardiolipin Binding Subunits within Bovine Heart CytochromecOxidase

Regulation of Cytochrome c Oxidase by Adenylic Nucleotides. Is Oxidative Phosphorylation Feedback Regulated by its End‐Products?

A 1H NMR study of bovine cytochrome oxidase

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A ¹H NMR study of bovine cytochrome oxidase