The effects of 2,4-dinitrophenol on mitochondrial oxidations

Jb, Chappell

doi:10.1042/bj0900237

Cited by 105 publications

(59 citation statements)

References 18 publications

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“…To achieve a defined oxygen concentration, oxygen-saturated 50 mM phosphate buffer (100% oxygen saturation at 25°C corresponds to 1262 M dioxygen (16), giving a final concentration of 631 M after mixing in the stopped-flow machine) was bubbled with nitrogen for different periods, and the oxygen concentration was measured polarographically. Oxygenated buffer solutions were transported to the stopped-flow device in gas-tight syringes with no gas head space to avoid loss of oxygen or contact with oxygen.…”

Section: Methodsmentioning

confidence: 99%

Kinetics of Interconversion of Ferrous Enzymes, Compound II and Compound III, of Wild-type Synechocystis Catalase-peroxidase and Y249F

Jakopitsch

Wanasinghe

Jantschko

et al. 2005

Journal of Biological Chemistry

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Section: Methodsmentioning

confidence: 99%

Kinetics of Interconversion of Ferrous Enzymes, Compound II and Compound III, of Wild-type Synechocystis Catalase-peroxidase and Y249F

Jakopitsch

Wanasinghe

Jantschko

et al. 2005

Journal of Biological Chemistry

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“…Malate (Mal), Glu, and ADP were added at the same time. 100% oxygen equals 237 nmol of oxygen/ml of respiratory buffer (51).…”

Section: Figmentioning

confidence: 99%

Rapid and Selective Oxygen-regulated Protein Tyrosine Denitration and Nitration in Mitochondria

Koeck

Hazen

et al. 2004

Journal of Biological Chemistry

167

133

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Growing evidence connects a cumulative formation of 3-nitrotyrosyl adducts in proteins as a marker for oxidative damage with the pathogenesis of various diseases and pathological conditions associated with oxidative stress. A physiological signaling role for protein nitration has also been suggested. Controlled "denitration" would be essential for such a contribution of protein nitration to cellular regulatory processes. Thus, we further characterized such a potentially controlled, reversible tyrosine nitration that occurs in respiring mitochondria during oxygen deprivation followed by reoxygenation, which we recently discovered. Mitochondria constitute cellular centers of protein nitration and are leading candidates for a "nitrative" regulation. Mitochondria are capable of completely eliminating 3-nitrotyrosyl adducts during 20 min of hypoxia-anoxia and undergoing a selective partial reduction after only 5 min. This denitration is independent of protein degradation but depends on the oxygen tension. Reoxygenation re-establishes protein tyrosine nitration patterns that are almost identical to the pattern that occurs before hypoxia-anoxia, with nitration levels that depend on the duration of hypoxia-anoxia. The identified mitochondrial targets of this process are critical for energy and antioxidant homeostasis and, therefore, cell and tissue viability. This cycle of protein nitration and denitration shows analogies to protein phosphorylation, and we demonstrate that the cycle meets most of the criteria for a cellular signaling mechanism. Taken together, our data reveal that protein tyrosine nitration in mitochondria can be controlled, is target-selective and rapid, and is dynamic enough to serve as a nitrative regulatory signaling process that likely affects cellular energy, redox homeostasis, and pathological conditions when these features become disturbed.

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“…For the evaluation of oxygen uptake, oxygen concentrations in the buffer solution, saturated with air, of 222.5 nmol O2 . ml-' at 30°C were assumed [42].…”

Section: -(12-['802]dihydroxyethyl)benzoic Acid Was Identifiedmentioning

confidence: 99%

Substrate‐modulated reactions of putidamonooxin

Wende

Bernhardt

Pfleger

1989

European Journal of Biochemistry

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1. 4-Methoxybenzoate monooxygenase is fairly nonspecific. The enzyme system with putidamonooxin as its oxygen-activating component catalyses: (a) 0-, S-and N-demethylation; (b) the oxygenation of 4-methylbenzoate and 4-methylmercaptobenzoate, with formation of 4-carboxybenzyl alcohol and 4-carboxyphenylmethyl sulfoxide, respectively, and (c) attack of the aromatic ring of 4-and 3-hydroxybenzoate and 4-aminobenzoate, yielding 3,4-dihydroxybenzoate and 4-amino-3-hydroxybenzoate, respectively.2. Compounds which are bound by the active sites of putidamonooxin have two essential features in common: a planar aromatic ring system, and a free carboxyl group attached to it.3. By a substrate-modulated reaction putidamonooxin can be induced to function not only as a monooxygenase but also as a peroxotransferase, i.e. it incorporates both atoms of the activated oxygen molecule into a substrate molecule. This finding supports the hypothesis that a mesomeric state of the iron . peroxo complex, [FeO,] ', is indeed the active oxygenating species of putidamonooxin.4. The lifetime of the ternary complex consisting of enzyme . iron-peroxo-complex . substrate is significantly prolonged by uncoupling and partially uncoupling substrates, except when it is inactivated by protonation of the iron . peroxo complex by a proton transported into the active sites by a special kind of substrate (i.e. isomers of monoaminobenzoate), with the direct formation of H202.5. The lifetime of the active oxygen species is determined by (a) the rate of the oxygenation reaction in the presence of tight-coupling substrates and (b) the rate of the oxygenation reaction as well as detoxification by the availability of a dissociable proton in the presence of partial uncoupling (and uncoupling) substrate analogues.6. The rate of the oxygenation reaction depends on the lifetime of the active oxygen species, [Fe02J+, in the presence of partial uncoupling substrates.7. The iron . peroxo complex attacks an aromatic ring system according to the empiric rules of electrophilic substitution, whereas the attack of aliphatic substituents at the aromatic ring is controlled by steric criteria.The 4-methoxybenzoate monooxygenase from Pseudomonas putidu (DSM no. 1868), in the presence of NADH and oxygen, catalyses the conversion of its physiological substrate 4-methoxybenzoate to 4-hydroxybenzoate via an unstable semiacetal intermediate [l]. The two constituents of this enzyme system, the oxygen-activating component called putidamonooxin and its reductase, the NADH -putidamonooxin oxidoreductase [a]

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The effects of 2,4-dinitrophenol on mitochondrial oxidations

Cited by 105 publications

References 18 publications

Kinetics of Interconversion of Ferrous Enzymes, Compound II and Compound III, of Wild-type Synechocystis Catalase-peroxidase and Y249F

Kinetics of Interconversion of Ferrous Enzymes, Compound II and Compound III, of Wild-type Synechocystis Catalase-peroxidase and Y249F

Rapid and Selective Oxygen-regulated Protein Tyrosine Denitration and Nitration in Mitochondria

Substrate‐modulated reactions of putidamonooxin

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