Influence of L-thyroxine on kynurenine 3-hydroxylase, monoamine oxidase, and rotenone-insensitive NADH-cytochrome C reductase in mitochondrial outer membrane

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.

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The influence of adrenalectomy on monoamine oxidase and NADH cytochrome c reductase in the rat heart

Journal of Pharmacy and Pharmacology ◽

10.1111/j.2042-7158.1977.tb11430.x ◽

1977 ◽

Vol 29 (1) ◽

pp. 657-663 ◽

Cited By ~ 8

Author(s):

LAURA DELLA CORTE ◽

B. A. CALLINGHAM

Keyword(s):

Cytochrome C ◽

Monoamine Oxidase ◽

Rat Heart ◽

Cytochrome C Reductase ◽

Nadh Cytochrome

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Effects of cytochrome c on the mitochondrial apoptosis-induced channel MAC

AJP Cell Physiology ◽

10.1152/ajpcell.00183.2003 ◽

2004 ◽

Vol 286 (5) ◽

pp. C1109-C1117 ◽

Cited By ~ 59

Author(s):

Liang Guo ◽

Dawn Pietkiewicz ◽

Evgeny V. Pavlov ◽

Sergey M. Grigoriev ◽

John J. Kasianowicz ◽

...

Keyword(s):

Cytochrome C ◽

Outer Membrane ◽

Cell Types ◽

Rnase A ◽

Mitochondrial Outer Membrane ◽

Dependent Manner ◽

Mitochondrial Apoptosis ◽

Noise Type ◽

Voltage Dependent

Recent studies indicate that cytochrome c is released early in apoptosis without loss of integrity of the mitochondrial outer membrane in some cell types. The high-conductance mitochondrial apoptosis-induced channel (MAC) forms in the outer membrane early in apoptosis of FL5.12 cells. Physiological (micromolar) levels of cytochrome c alter MAC activity, and these effects are referred to as types 1 and 2. Type 1 effects are consistent with a partitioning of cytochrome c into the pore of MAC and include a modest decrease in conductance that is dose and voltage dependent, reversible, and has an increase in noise. Type 2 effects may correspond to “plugging” of the pore or destabilization of the open state. Type 2 effects are a dose-dependent, voltage-independent, and irreversible decrease in conductance. MAC is a heterogeneous channel with variable conductance. Cytochrome c affects MAC in a pore size-dependent manner, with maximal effects of cytochrome c on MAC with conductance of 1.9–5.4 nS. The effects of cytochrome c, RNase A, and high salt on MAC indicate that size, rather than charge, is crucial. The effects of dextran molecules of various sizes indicate that the pore diameter of MAC is slightly larger than that of 17-kDa dextran, which should be sufficient to allow the passage of 12-kDa cytochrome c. These findings are consistent with the notion that MAC is the pore through which cytochrome c is released from mitochondria during apoptosis.

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Characterization of NADH-cytochrome c reductase, a component of benzoate 1,2-dioxygenase system from Pseudomonas arvilla c-1.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)34255-2 ◽

1978 ◽

Vol 253 (24) ◽

pp. 8848-8853

Author(s):

M. Yamaguchi ◽

H. Fujisawa

Keyword(s):

Cytochrome C ◽

Cytochrome C Reductase ◽

Nadh Cytochrome

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Properties of a cytochrome c-enriched light particulate fraction isolated from the photosynthetic bacterium Rhodopseudomonas spheroides

Biochemical Journal ◽

10.1042/bj1740267 ◽

1978 ◽

Vol 174 (1) ◽

pp. 267-275 ◽

Cited By ~ 8

Author(s):

J Barrett ◽

C N Hunter ◽

O T G Jones

Keyword(s):

Cytochrome C ◽

Sodium Dodecyl ◽

Photosynthetic Bacterium ◽

Particulate Fraction ◽

Cytochrome C Reductase ◽

Cytochrome C2 ◽

Succinate Cytochrome C Reductase ◽

Bulk Membrane ◽

Nadh Cytochrome ◽

Rhodopseudomonas Spheroides

Differential centrifugation of suspensions of French-press-disrupted Rhodopseudomonas spheroides yielded a light particulate fraction that was different in many properties from the bulk membrane fraction. It was enriched in cytochrome c and had a low cytochrome b content. When prepared from photosynthetically grown cells this fraction had a very low specific bacteriochlorophyll content. The cytochrome c of the light particles differed in absorption maxima at 77K from cytochrome c2 attached to membranes; there was pronounced splitting of the alpha-band, as is found in cytochrome c2 free in solution. Potentiometric titration at A552–A540 showed the presence of two components that fitted an n = 1 titration; one component had a midpoint redox potential of +345mV, like cytochrome c2 in solution, and the second had E0′ at pH 7.0 of +110 mV, and they were present in a ratio of approx. 2:3. Difference spectroscopy at 77K showed that the spectra of the two components were very similar. More of a CO-binding component was present in particles from photosynthetically grown cells. Light membranes purified by centrifugation on gradients of 5–60% (w/w) sucrose retained the two c cytochromes; they contained no detectable succinate-cytochrome c reductase or bacteriochlorophyll and very little ubiquinone, but they contained NADH-cytochrome c reductase and some phosphate. Electrophoresis on sodium dodecyl sulphate/polyacrylamide gels showed that the light membranes of aerobically and photosynthetically grown cells were very similar and differed greatly from other membrane fractions of R. spheroides.

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Endoplasmic reticulum membrane isolated from small-intestinal epithelial cells: enzyme and protein components

Journal of Cell Science ◽

10.1242/jcs.52.1.215 ◽

1981 ◽

Vol 52 (1) ◽

pp. 215-222

Author(s):

M. Fujita ◽

H. Ohta ◽

T. Uezato

Keyword(s):

Endoplasmic Reticulum ◽

Epithelial Cells ◽

Cytochrome C ◽

Endoplasmic Reticulum Membrane ◽

Dependent Manner ◽

Cytochrome C Reductase ◽

Basolateral Membranes ◽

Nadh Cytochrome ◽

Protein Components ◽

A Minor

Endoplasmic reticulum membrane-rich fraction was obtained by subfractionation of the light microsomes from mouse jejunal mucosal epithelial cells. It was marked by high glucose-6-phosphatase, NADPH-cytochrome c reductase, and NADH-cytochrome c reductase activities and low Na+,K+-ATPase activity. The enrichment of Na+,K+-ATPase was 180-fold higher in the basolateral membranes than in the endoplasmic reticulum membrane-rich fraction relative to glucose-6-phosphatase. The protein peak that was phosphorylated in a Na-dependent manner was prominent in the basolateral membranes while it was a minor peak in the endoplasmic reticulum membrane-rich fraction. Under the electron microscope the fraction was seen to be composed of homogeneous small vesicles with thin smooth membranes.

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