Search results for "NADH-Ubiquinone Oxidoreductase"

showing 3 items of 3 documents

New evidence for the multiplicity of ubiquinone- and inhibitor-binding sites in the mitochondrial complex I.

2000

Determination of the number of ubiquinone- and inhibitor-binding sites in the mitochondrial complex I (NADH:ubiquinone oxidoreductase) is a controversial question with a direct implication for elaborating a suitable model to explain the bioenergetic mechanism of this complicated enzyme. We have used combinations of both selective inhibitors and common ubiquinone-like substrates to demonstrate the multiplicity of the reaction centers in the complex I in contrast with competition studies that have suggested the existence of a unique binding site for ubiquinone. Our results provide new evidence for the existence of at least two freely exchangeable ubiquinone-binding sites with different specif…

BioenergeticsStereochemistryUbiquinoneSubmitochondrial ParticlesBiophysicsBiologyIn Vitro TechniquesBiochemistryModels BiologicalMitochondria HeartSubstrate SpecificityOxidoreductaseAnimalsNADH NADPH OxidoreductasesBinding siteMultiplicity (chemistry)Molecular Biologychemistry.chemical_classificationNADH-Ubiquinone OxidoreductaseBinding SitesElectron Transport Complex IKineticsEnzymechemistryBiochemistryCattleEnergy MetabolismMitochondrial Complex IArchives of biochemistry and biophysics
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Mitochondrial complex I: new insights from inhibitor assays

2000

The NADH:ubiquinone oxidoreductase (complex I) of the mitochondrial respiratory chain is by far the most complicated of the proton-translocating enzymes involved in the oxidative phosphorylation. Many clues regarding both electron transfer and proton translocation are still unknown. In this sense, inhibitor assays are relevant and useful pieces for elaborating a suitable model to explain the elusive bioenergetic mechanism of this enzyme. This short review presents the most recent advances in inhibitor studies and highlights the major controversies.

Proton translocationchemistry.chemical_classificationNADH-Ubiquinone OxidoreductaseMechanism (biology)Cell BiologyPlant ScienceGeneral MedicineOxidative phosphorylationBiologyMitochondrial respiratory chainEnzymeBiochemistrychemistryOxidoreductaseMitochondrial Complex IProtoplasma
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Kinetic characterization of mitochondrial complex I inhibitors using annonaceous acetogenins

1999

The NADH:ubiquinone oxidoreductase (complex I) of the mitochondrial respiratory chain is by far the largest and most complicated of the proton-translocating enzymes involved in the oxidative phosphorylation. Many clues regarding the electron pathways from matrix NADH to membrane ubiquinone and the links of this process with the translocation of protons are highly controversial. Different types of inhibitors become valuable tools to dissect the electron and proton pathways of this complex enzyme. Therefore, further knowledge of the mode of action of complex I inhibitors is needed to understand the underlying mechanism of energy conservation. This study presents for the first time a detailed …

UbiquinoneSubmitochondrial ParticlesBiophysicsOxidative phosphorylationBiologyBiochemistryMitochondria HeartLactonesOxidoreductaseRotenoneNAD(P)H Dehydrogenase (Quinone)Mammalian enzymeAnimalsFuransMolecular Biologychemistry.chemical_classificationNADH-Ubiquinone OxidoreductasePlant ExtractsNADKineticsMitochondrial respiratory chainEnzymechemistryBiochemistryCattleAnnonaceous AcetogeninsMitochondrial Complex I
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