Oxidative phosphorylation in an enzyme fraction from mitochondrial extracts

Cooper, Cecil; Devlin, Thomas M.; Lehninger, Albert L.

doi:10.1016/0006-3002(55)90034-2

Cited by 51 publications

(21 citation statements)

References 4 publications

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“…Rats were killed by cervical dislocation and liver was rapidly removed and put into ice-cold 225 mM sucrose, 20 mM Tris/HCI, pH 7.2, 1 mM EDTA. Mitochondria were isolated according to [9] Rate of electron transfer at the levels of complex I and complexes II/III. The oxidation of NADH by complex I was recorded with decylubiquinone as electron acceptor in 10 mM Tris/maleate, pH 7.2, 2 pg antimycin, 0.3 mM decylubiquinone (Sigma) and 0.1 mM NADH in a final volume of 1 ml.…”

Section: Methodsmentioning

confidence: 99%

Mechanisms of Inhibition and Uncoupling of Respiration in Isolated Rat Liver Mitochondria by the General Anesthetic 2,6‐Diisopropylphenol

Kigoulet

Devin

Avéret

et al. 1996

European Journal of Biochemistry

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We investigated the effects of 2,6-diisopropylphenoI on oxidative phosphorylation of isolated rat liver mitochondria. Diisopropylphenol strongly inhibits state-3 and uncoupled respiratory rates, when glutamate and malate are the substrates, as a direct consequence of the limitation of electron transfer at the level of complex I. In addition, diisopropylphenol acts as an uncoupler in non-phosphorylating mitochondria, which leads to an increase in respiratory rate and a large decrease in proton-motive force. However, such effects cannot be due to the classical protonophoric property of this drug, since addition of ADP plus oligomycin before diisopropylphenol avoids this increase in proton permeability, and in phosphorylating mitochondria, the ATP/O ratio is not significantly affected by diisopropylphenol addition. In the absence of added ADP, diisopropylphenol modifies some mitochondrial ATPases in such a way that they become insensitive to oligomycin and unable to couple proton movement to ATP synthesis or hydrolysis. However. these modified enzymes can catalyse passive proton permeability, which leads to uncoupling. Addition of ADP before diisopropylphenol prevents these changes. We propose that ADP induces a change in conformation of ATPase, which leads to insensitivity of this complex towards diisopropylphenol.In conclusion, we show that diisopropylphenol has two main effects on rat liver mitochondria: inhibition of the respiratory chain at the level of complex I level and modification of ATPase such that, in the absence of phosphorylation, it catalyses a H' leak, which becomes negligible when oxidative phosphorylation is functional.Keywords: 2,6-diisopropylphenoI; rat liver mitochondria; respiratory chain ; oxidative phosphorylation ; adenosine triphosphatase.Even though general anesthetics have a great variety of molecular structures and have been reported to affect different mitochondrial functions, most have been characteri~ed as uncouplers of oxidative phosphorylation. For instance, halothane and chloroform induce stimulation of state-4 respiration, inhibition of ATP synthesis and increase basal ATPase activity; all these effects define an uncoupling process of oxidative phosphorylation [I -31. However, in contrast to the wide class of classical uncouplcrs, c.g. protonophores or ionophores, halothane and chloroform only very slightly increase the proton and/or ion conductance of the inner mitochondrial membrane and cause only a slight depression of proton-motive force (LIP). That these strong uncouplers can act without a significant effect on bulk-to-bulk d p has been considered as evidence in favour of the existence of either a parallel (intramembranal) coupling pathway for pro- H ' -transporting ATP synthase (EC 3.6.1 34).tons [4] or a mechanism of intrinsic uncoupling at the protonpump level 151.2,6-diisopropyIphenol, an alkyl-substituted phenol currently used as an intravenous general anesthetic, has previously been reported to reduce the transmembrane difference in electrical potential and to increas...

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Section: Methodsmentioning

confidence: 99%

Mechanisms of Inhibition and Uncoupling of Respiration in Isolated Rat Liver Mitochondria by the General Anesthetic 2,6‐Diisopropylphenol

Kigoulet

Devin

Avéret

et al. 1996

European Journal of Biochemistry

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“…Other experiments had shown that diphosphopyridine nucleotide was an essential component of isolated mitochondria from several sources (guinea pig, rat, etc.) and an essential step in mitochondrial oxidative phosphorylation from P/O ratio and ATP production (14). Using the double-beam spectrometer, Chance showed that ADP utilization and ATP production by use of O 2 was coupled to the mitochondrial oxidation of the many mitochondrial enzymes.…”

Section: Pnmr Spectroscopymentioning

confidence: 99%

Skeletal muscle energetics with PNMR: personal views and historic perspectives

Chance

Nioka

et al. 2006

NMR in Biomedicine

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This article reviews historical and current NMR approaches to describing in vivo bioenergetics of skeletal muscles in normal and diseased populations. It draws upon the first author's more than 70 years of personal experience in enzyme kinetics and the last author's physiological approaches. The development of in vivo PNMR jointly with researchers around the world is described. It is explained how non-invasive PNMR has advanced human exercise biochemistry, physiology and pathology. Further, after a brief explanation of bioenergetics with PNMR on creatine kinase, anerobic glycolysis and mitochondrial oxidative phosphorylation, some basic and controversial subjects are focused upon, and the authors' view of the subjects are offered, with questions and answers. Some of the research has been introduced in exercise physiology. Future directions of NMR on bioenergetics, as a part of system biological approaches, are indicated.

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“…All these treatments made the cells immediately immotile. Filipin (Demel, van Deenen & Kinsky, 1965) and digitonin (Cooper & Lehninger, 1956) are known to damage cell membranes apparently by specific interaction with sterols.…”

Section: Introductionmentioning

confidence: 99%

In-Vitro Uptake of Zinc by Boar Spermatozoa

Westmoreland¹,

First²,

Hoekstra³

1967

Reproduction

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Summary. Boar spermatozoa accumulated zinc when stored in vitro in contact with boar seminal plasma. Zinc uptake was much more rapid when the spermatozoa were stored at 5\ s=deg\C than when stored at 30\s=deg\C.Freezing or the addition of the membrane-damaging agents, filipin or digitonin, before storage at 30\ s=deg\ C, caused rapid zinc uptake, but addition of the metabolic inhibitors, fluoride or iodoacetate did not accelerate zinc uptake. It is concluded that when membrane damage occurs spermatozoa accumulate zinc from the seminal plasma and that zinc content of spermatozoa is dependent on time of sampling after ejaculation, conditions of storage and membrane integrity.

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Oxidative phosphorylation in an enzyme fraction from mitochondrial extracts

Cited by 51 publications

References 4 publications

Mechanisms of Inhibition and Uncoupling of Respiration in Isolated Rat Liver Mitochondria by the General Anesthetic 2,6‐Diisopropylphenol

Mechanisms of Inhibition and Uncoupling of Respiration in Isolated Rat Liver Mitochondria by the General Anesthetic 2,6‐Diisopropylphenol

Skeletal muscle energetics with PNMR: personal views and historic perspectives

In-Vitro Uptake of Zinc by Boar Spermatozoa

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