title: [One- and two-electron reduction of ubiquinone homologs by NADH- dehydrogenase preparations from the mitochondrial respiratory chain].
abstract: The mechanism of ubiquinone homologs reduction by different preparations of mitochondrial NADH dehydrogenase: complex I within submitochondrial particles, isolated NADH-ubiquinone oxidoreductase and soluble low molecular weight NADH dehydrogenase, has been investigated. It has been shown that NADH oxidation via the rotenone-insensitive reaction is associated with one-electron reduction of low molecular weight ubiquinone homologs (Q0, Q1, Q2) to semiquinone with subsequent fast oxidation of the latter by atmospheric oxygen to form a superoxide radical. The two-electron ubiquinone reduction to quinol in the rotenone-sensitive reaction is unaccompanied by the semiquinone release from the enzyme active center into the surrounding solution.
authors.forename: V D
authors.initials: VD
authors.lastname: Sled'
authors.forename: V N
authors.initials: VN
authors.lastname: Zinich
authors.forename: A B
authors.initials: AB
authors.lastname: Kotliar
mesh_terms: D000818:Animals; D002417:Cattle; D003579:Cytochrome Reductases / Q000378:metabolism*; D004583:Electrons; D009206:Myocardium / Q000201:enzymology; D009245:NADH Dehydrogenase / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D012402:Rotenone / Q000494:pharmacology; D013367:Submitochondrial Particles / Q000201:enzymology; D014451:Ubiquinone / Q000378:metabolism*
chemical_list: D012402:Rotenone; D014451:Ubiquinone; D003579:Cytochrome Reductases; D009245:NADH Dehydrogenase
vernacular_title: Odno- i dvukhélektronnoe vosstanovlenie gomologov ubikhinona preparatami NADH-degidrogenazy dykhatel'noĭ tsepi mitokhondriĭ.