Spectroscopic resolution of the “iron‐flavoprotein trough” of the respiratory chain of submitochondrial particles from <i>Torulopsis utilis</i>

Ragan, C I; Clegg, Roger A.; Haddock, Bruce A.; Light, P.Ann; Garland, P. B.

doi:10.1016/0014-5793(90)80007-6

Cited by 9 publications

(3 citation statements)

References 8 publications

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“…(The specific activity of the enzyme was Recovery of the extinction change at 460nm on reduction by NADH. Studies on ETP from a number of phenotypic modifications of T. utili8 led us to conclude that there were two species of non-haem iron involved in the oxidation of NADH ___,__,__,__,__,_ (Ragan et al 1970;. One 5 6 7 8 9 10 of these, denoted species 1, was supposedly a nonhaem-iron-containing flavoprotein, reducible only by NADH, and located on the substrate side of the NADH dehydrogenase.…”

Section: 06mentioning

confidence: 99%

“…Iron or sulphate limited growth of the yeast Torulopsis utilis leads to loss of site I energy conservation and loss of sensitivity to the respiratory inhibitors rotenone or piericidin A (Light, Ragan, Clegg & Garland, 1968;) as well as to loss of mitochondrial non-haem iron and acid-labile sulphide (Clegg et al 1969;Clegg & Garland, 1971;. Spectroscopic modification of the electron transport particles accompanying these phenotypic changes enabled us to characterize more closely the nature of the respiratory carriers involved in the oxidation of NADH, in the site I energy conservation and in the inhibition by piericidin A (Ragan, Clegg, Haddock, Light & Garland, 1970. The obvious extension of this work was to attempt an isolation of these carriers from the different phenotypes.…”

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The purification and properties of the respiratory-chain reduced nicotinamide–adenine dinucleotide dehydrogenase of Torulopsis utilis

Tottmar

Ragan

1971

Biochemical Journal

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1. An NADH-ferricyanide reductase activity has been isolated from the respiratory chain of Torulopsis utilis by using detergents. The isolated enzyme contains non-haem iron, acid-labile sulphide and FMN in the molar proportions 27.5:28.4:1. The preparation is free of FAD and largely free of cytochrome. 2. The enzyme catalyses ferricyanide reduction by NADPH at about 1% of the rate with NADH, and reacts poorly with acceptors other than ferricyanide. The rates of reduction of some acceptors are, as percentages of the rate with ferricyanide: menadione, 0.35%; lipoate, 0.01%; cytochrome c, 0.065%; dichlorophenolindophenol, 0.35%; ubiquinone-1, 0.08%. 3. Several properties of submitochondrial particles of T. utilis (non-haem iron, acid-labile sulphide, FMN and an NADH-reducible electron-paramagnetic-resonance signal) were found to co-purify with the NADH-ferricyanide reductase activity. Thus about 70% of the FMN and, within the limits of accuracy of the experiments, 100% of the non-haem iron and acid-labile sulphide of submitochondrial particles derived from T. utilis cells grown under conditions of glycerol limitation (but relatively low iron availability) can be attributed to the NADH-ferricyanide reductase. 4. It was also shown that the component of submitochondrial particles specifically bleached at 460nm by NADH [species 1 of Ragan & Garland (1971)] co-purifies with the NADH-ferricyanide reductase. 5. This successful purification of an NADH dehydrogenase from T. utilis forms a starting point for investigating the molecular properties of phenotypically modified mitochondrial NADH oxidation pathways that lack energy conservation between NADH and the cytochromes.

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confidence: 99%

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confidence: 99%

The purification and properties of the respiratory-chain reduced nicotinamide–adenine dinucleotide dehydrogenase of Torulopsis utilis

Tottmar

Ragan

1971

Biochemical Journal

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“…An obvious objective of making a detailed spectroscopic study of the submitochondrial particles derived from these cells was to ascertain whether the changes in mitochondrial function were paralleled by changes in the concentration of spectroscopically identifiable nonhaem iron proteins. A preliminary account of this work has been published (Ragan, Clegg, Haddock, Light & Garland, 1970).…”

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Spectroscopic studies of flavoproteins and non-haem iron proteins of submitochondrial particles of Torulopsis utilis modified by iron- and sulphate-limited growth in continuous culture

Ragan

Garland

1971

Biochemical Journal

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1. A spectroscopic resolution has been made of the components contributing to the ;iron-flavoprotein' trough extending from 450 to 520nm in the reduced-minus-oxidized difference spectrum of submitochondrial particles of Torulopsis utilis. 2. Seven components were identified other than cytochrome b, ubiquinone and succinate dehydrogenase. On the basis of the effects of iron- and sulphate-limited growth of cells on their subsequently derived electron-transport particles, and also by consideration of analytical measurements of the concentration of FMN, FAD, non-haem iron and acid-labile sulphide in the electron-transport particles in relation to the magnitude of the spectroscopic changes, it was possible to identify five of these components as follows: species 1a, the flavin of NADH dehydrogenase ferroflavoprotein; species 1b, the iron-sulphur component of NADH dehydrogenase ferroflavoprotein; species 1', the flavin of an NADPH dehydrogenase; species 2, an iron-sulphur or ferroflavoprotein component; species 3, the flavin of l-3-glycerophosphate dehydrogenase. Two additional components were a fluorescent flavoprotein, probably lipoamide dehydrogenase, and a b-type cytochrome reducible by NADH or NADPH but not reoxidizable by the respiratory chain. 3. Species 1b and 2 were undetectable in electron-transport particles from iron- or sulphate-limited cells, but could be recovered in vivo under non-growing conditions. 4. The recovery in vivo of species 2 but not species 1b was inhibited by cycloheximide. 5. The recovery of species 1b correlates with the recovery of site 1 conservation. 6. The recovery of species 1b with species 2 correlates with the recovery of piericidin A sensitivity. 7. Evidence is presented for an NADPH dehydrogenase distinct from NADH dehydrogenase. The oxidation of NADH and NADPH by the respiratory chain is sensitive to piericidin A, and an iron-sulphur protein common to both pathways (species 2) is suggested as the piericidin A-sensitive component. 8. The approximate E'(0) (pH7.0) values of species 1 (a and b, low potential) and species 2 (high potential) indicate that site 1 energy conservation occurs between the levels of species 1 (a and b) and species 2.

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Influence of environment on mitochondrial function in yeast

Light

1972

J. Appl. Chem.

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Spectroscopic resolution of the “iron‐flavoprotein trough” of the respiratory chain of submitochondrial particles from Torulopsis utilis

Cited by 9 publications

References 8 publications

The purification and properties of the respiratory-chain reduced nicotinamide–adenine dinucleotide dehydrogenase of Torulopsis utilis

The purification and properties of the respiratory-chain reduced nicotinamide–adenine dinucleotide dehydrogenase of Torulopsis utilis

Spectroscopic studies of flavoproteins and non-haem iron proteins of submitochondrial particles of Torulopsis utilis modified by iron- and sulphate-limited growth in continuous culture

Influence of environment on mitochondrial function in yeast

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