An electron-transport system associated with the outer membrane of liver mitochondria. A biochemical and morphological study.
TLDR
Experiments with tritiated NADH are described which demonstrate that this "external" pathway of NADH oxidation resembles stereochemically the NADH-cytochrome c reductase system of liver microsomes, and differs from the respiratory chain-linked NADH dehydrogenase.Abstract:
Preparations of rat-liver mitochondria catalyze the oxidation of exogenous NADH by added cytochrome c or ferricyanide by a reaction that is insensitive to the respiratory chain inhibitors, antimycin A, amytal, and rotenone, and is not coupled to phosphorylation. Experiments with tritiated NADH are described which demonstrate that this "external" pathway of NADH oxidation resembles stereochemically the NADH-cytochrome c reductase system of liver microsomes, and differs from the respiratory chain-linked NADH dehydrogenase. Enzyme distributation data are presented which substantiate the conclusion that microsomal contamination cannot account for the rotenone-insensitive NADH-cytochrome c reductase activity observed with the mitochondria. A procedure is developed, based on swelling and shrinking of the mitochondria followed by sonication and density gradient centrifugation, which permits the separation of two particulate subfractions, one containing the bulk of the respiratory chain components, and the other the bulk of the rotenone-insensitive NADH-cytochrome c reductase system. Morphological evidence supports the conclusion that the former subfraction consists of mitochondria devoid of outer membrane, and that the latter represents derivatives of the outer membrane. The data indicate that the electron-transport system associated with the mitochondrial outer membrane involves catalytic components similar to, or identical with, the microsomal NADH-cytochrome b5 reductase and cytochrome b5.read more
Citations
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Enzymatic properties of the inner and outer membranes of rat liver mitochondria
TL;DR: The inner membrane-matrix fraction retained a high degree of morphological and biochemical integrity and exhibited a high respiratory rate and respiratory control when assayed in a sucrose-mannitol medium containing EDTA.
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Biochemical, physiological and medical aspects of ubiquinone function
TL;DR: A brief review of current knowledge concerning some biochemical, physiological and medical aspects of the function of ubiquinone (coenzyme Q) in mammalian organisms can be found in this article.
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Mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes: a distinctive clinical syndrome.
Steven G. Pavlakis,Peter C. Phillips,Salvatore DiMauro,Darryl C. De Vivo,Darryl C. De Vivo,Lewis P. Rowland +5 more
TL;DR: It is believed that MELAS represents a distinctive syndrome and that it can be differentiated from two other clinical disorders that also are associated with mitochondrial myopathy and cerebral disease: Kearns‐Sayre syndrome and the myoclonus epilepsy ragged red fiber syndrome.
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Mitochondrial superoxide simutase. Site of synthesis and intramitochondrial localization.
TL;DR: This result indicates that the manganoenzyme, although localized in the mitochondrial matrix, is actually made under the directions of the nuclear genome and that its biosynthesis therefore probably takes place in the cytosol.
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Lipids of mitochondria
TL;DR: The lipid content and lipid composition of mitochondria, a comparison between mitochondrial and other cellular membranes, and mitocbondria from microorganisms are compared.
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The Carbon Monoxide-binding Pigment of Liver Microsomes I. EVIDENCE FOR ITS HEMOPROTEIN NATURE
Tsuneo Omura,Ryo Sato +1 more
TL;DR: The present paper gives a detailed account of the investigations on rabbit liver microsomes and crude microsomal digests, which have led to postulate the hemoprotein nature of the pigment.
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Tissue fractionation studies. 6. Intracellular distribution patterns of enzymes in rat-liver tissue
TL;DR: The results are shown to favour the ferryl ion structure, or an isomer of this structure, for the higher oxidation state, and theHigher oxidation state may provisionally be named ferrylmyoglobin.
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Hepatic Triphosphopyridine Nucleotide-Cytochrome c Reductase: Isolation, Characterization, and Kinetic Studies
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