title: The interaction between mitochondrial NADH-ubiquinone oxidoreductase and ubiquinol-cytochrome c oxidoreductase. Restoration of ubiquinone-pool behaviour.
abstract: 1. In the inner mitochondrial membrane, dehydrogenases and cytochromes appear to act independently of each other, and electron transport has been proposed to occur through a mobile pool of ubiquinone-10 molecules [Kröger & Klingenberg (1973) Eur. J. Biochem. 34, 358--368]. 2. Such behaviour can be restored to the interaction between purified Complex I and Complex III by addition of phospholipid and ubiquinone-10 to a concentrated mixture of the Complexes before dilution. 3. A model is proposed for the interaction of Complex I with Complex III in the natural membrane that emphasizes relative mobility of the Complexes rather than ubiquinone-10. Electron transfer occurs only through stoicheiometric Complex I-Complex III units, which, however, are formed and re-formed at rates higher than the rate of electron transfer.
mesh_terms: D000968:Antimycin A / Q000494:pharmacology; D003579:Cytochrome Reductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003574:Cytochrome c Group; D003580:Cytochromes / Q000378:metabolism; D004734:Energy Metabolism; D004789:Enzyme Activation; D066298:In Vitro Techniques; D007700:Kinetics; D008929:Mitochondria, Heart / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D011808:Quinone Reductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012402:Rotenone / Q000494:pharmacology; D014451:Ubiquinone
chemical_list: D003574:Cytochrome c Group; D003580:Cytochromes; D009097:Multienzyme Complexes; D010743:Phospholipids; D012402:Rotenone; D014451:Ubiquinone; D000968:Antimycin A; D009247:NADH, NADPH Oxidoreductases; D003579:Cytochrome Reductases; D011808:Quinone Reductases