Menadiol as an electron donor for reversed oxidative phosphorylation in submitochondrial particles

Taggart, William; Sanadi, D.R.

doi:10.1016/0005-2728(72)90171-5

Cited by 3 publications

(2 citation statements)

References 11 publications

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“…transport chain in a redox type reaction is indicated in Table VI. While dithiothreitol by itself will not serve as an electron source for reverse electron transport, dithiothreitol can reduce certain quiñones such as menadione (Taggart and Sanadi, 1972) or DQ (unpublished work), and the reduced quiñones can then donate electrons for ATP dependent reverse electron transport. (Table VI shows that C-OH-BQ can also mediate electron transport from dithiothreitol to MOP for an ATP-dependent reverse electron transport which is completely rotenone sensitive and partially chloroquine sensitive.…”

Section: Resultsmentioning

confidence: 99%

Inhibition of mitochondrial electron transport by hydroxy-substituted 1,4-quinones

Phelps¹,

Crane²

1975

Biochemistry

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Mitochondrial electron transport from NADH, succinate, or duroquinol to oxygen is inhibited by 5-omega-cyclohexyl-n-pentyl-6-hydroxy-2,3-dimethoxy-1,4-benzoquinone and 2-omega-cyclohexyl-n-pentyl-3-hydroxy-1,4-napthoquinone. Assays of partial electron transport activities indicate a site of inhibition in the region between the site of duroquinol oxidation and cytochrome c reduction. Effects of the inhibitors on cytochrome spectra indicate the principle site of inhibition is between cytochromes of the b group and cytochrome c1. The quinones do not induce increased reduction of the b566 as does antimycin A. The benzoquinone can induce a partial antimycin insensitive bypass of the cytochromes b-c1 region. Uncoupling agents do not affect the extent of inhibition as has been reported for analogous naphthoquinone inhibitors.

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Section: Resultsmentioning

confidence: 99%

Inhibition of mitochondrial electron transport by hydroxy-substituted 1,4-quinones

Phelps¹,

Crane²

1975

Biochemistry

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“…When samples were required a cuvette with an adjustable lid was used to prevent the ingress of 02-The reaction medium contained (final concentrations) 0.3 M-mannitol, 10mM-KCl, 5 mm-MgCl2 and 10mM-potassium phosphate buffer, pH 7.2, unless otherwise stated; 8.3 mM-succinate, 2-8.3 mMtrimethylquinol, 2 mM-duroquinone or 2 mM-menadione reduced with KBH4 (Lawford & Garland, 1973) was used as substrate. Since high concentrations of oxidized quinones derived from the reduced quinones appeared to be deleterious in some experiments, the quinones were also used at lower concentrations (1 7pM) together with 0.3 mM-dithioerythritol to ensure reduction (Taggart & Sanadi, 1972). High concentrations of reduced quinone also gave some non-enzymic 02 uptake.…”

Section: Methodsmentioning

confidence: 99%

Energy conservation by the plant mitochondrial cyanide-insensitive oxidase. Some additional evidence

Wilson¹

1980

Biochemical Journal

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Several measures of energy conservation, namely ADP/O ratio, P/O ratio, ATP/O ratio and phosphorylation detected by continuous assay with purified firefly luciferase and luciferin, all show phosphorylation can occur with mung-bean mitochondria at cyanide concentrations sufficient to inhibit the cytochrome oxidase system. Phosphorylation in the presence of cyanide is uncoupler- oligomycin- and salicylhydroxamate-sensitive. The participation of phosphorylation site 1 is excluded, phosphorylation being attributable to a single phosphorylation site associated with the cyanide-insensitive oxidase. The cyanide-insensitive oxidase has also been shown to support a variety of other energy-linked functions, namely, Ca2+ uptake, reversed electron transport and the maintenance of a membrane potential detected by the dye probes 8-anilinonaphthalene-1-sulphonate and safranine. High concentrations of cyanide have uncoupler-like activity, decreasing the ADP/O ratio and the t 1/2 for the decay of a pH pulse through the the mitochondrial membrane. This uncoupler-like effect is most marked with aged mitochondria. The observations of energy conservation attributable to the cyanide-insensitive oxidase are compared with other reports where it is concluded that the alternative oxidase is uncoupled.

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NADH-ubiquinone oxidoreductase

Ragan

1976

Biochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics

121

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Menadiol as an electron donor for reversed oxidative phosphorylation in submitochondrial particles

Cited by 3 publications

References 11 publications

Inhibition of mitochondrial electron transport by hydroxy-substituted 1,4-quinones

Inhibition of mitochondrial electron transport by hydroxy-substituted 1,4-quinones

Energy conservation by the plant mitochondrial cyanide-insensitive oxidase. Some additional evidence

NADH-ubiquinone oxidoreductase

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