The electron transport system of the halophilic purple nonsulfur bacterium Rhodospirillum salinarum . 1. A functional and thermodynamic analysis of the respiratory chain in aerobically and photosynthetically grown cells

1997 ◽  
Vol 168 (4) ◽  
pp. 302-309 ◽  
Author(s):  
Giovanni Moschettini ◽  
Alejandro Hochkoeppler ◽  
Barbara Monti ◽  
Bruna Benelli ◽  
D. Zannoni
Keyword(s):  
Electron Transport ◽  
Respiratory Chain ◽  
Thermodynamic Analysis ◽  
Transport System ◽  
Electron Transport System ◽  
Purple Nonsulfur Bacterium ◽  
Rhodospirillum Salinarum

scholarly journals AN ELECTRON-TRANSPORT SYSTEM ASSOCIATED WITH THE OUTER MEMBRANE OF LIVER MITOCHONDRIA

1967 ◽  
Vol 32 (2) ◽  
pp. 415-438 ◽  
Author(s):  
Gian Luigi Sottocasa ◽  
Bo Kuylenstierna ◽  
Lars Ernster ◽  
Anders Bergstrand
Keyword(s):  
Electron Transport ◽  
Cytochrome C ◽  
Outer Membrane ◽  
Respiratory Chain ◽  
Transport System ◽  
Cytochrome B5 ◽  
Liver Mitochondria ◽  
Electron Transport System ◽  
Cytochrome C Reductase ◽  
Nadh Cytochrome

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.

Respiratory chain defect of myocardial mitochondria in idiopathic dilated cardiomyopathy of Doberman pinscher dogs

1992 ◽  
Vol 70 (11) ◽  
pp. 1529-1533 ◽  
Author(s):  
Laura Jill McCutcheon ◽  
Colin Robert Cory ◽  
Linda Nowack ◽  
Hua Shen ◽  
Medhi Mirsalami ◽  
...  
Keyword(s):  
Electron Transport ◽  
Dilated Cardiomyopathy ◽  
Respiratory Chain ◽  
Transport System ◽  
Nadh Dehydrogenase ◽  
Genetic Defect ◽  
Electron Transport System ◽  
Idiopathic Dilated Cardiomyopathy ◽  
Acid Oxidation ◽  
Doberman Pinscher

Idiopathic dilated cardiomyopathy (IDCM) is a primary myocardial disease of unknown cause. We tested the hypothesis that IDCM was associated with a myocardial metabolic defect by determining a comprehensive biochemical profile of metabolite concentrations and enzyme activities for the major metabolic pathways of the myocardium. We used the Doberman pinscher breed as a naturally occurring canine model of IDCM and compared its myocardial profile with that of healthy adult mongrels. Compared with controls, myocardium in IDCM had markedly reduced mitochondrial electron transport activity and myoglobin concentration, in association with acidosis and energy depletion following anoxic challenge: 60% decreased NADH dehydrogenase and 50% decreased ATP synthetase activities; 90% decreased myoglobin concentration; and 30% reduced ATP and 50% increased lactate and proton concentrations. Sarcoplasmic reticulum Ca2+-transport ATPase was decreased by 42%. There was a 15% compensatory increase in fatty acid oxidation and Krebs cycle activity. Other biochemical changes were mild by comparison with the mitochondrial defects. We conclude that IDCM is associated with a marked impairment of mitochondrial production of ATP, arising from decreased activity of the mitochondrial electron transport system, including myoglobin. These changes may be secondary to an underlying genetic defect or may indicate a deficiency of the mitochondrial respiratory chain that predisposes this breed to heart failure.Key words: dilated cardiomyopathy, congestive heart failure, mitochondria, electron transport system, myoglobin, NADH dehydrogenase.

scholarly journals Studies of the Electron Transport System

1961 ◽  
Vol 236 (6) ◽  
pp. 1857-1862 ◽  
Author(s):  
D.E. Griffiths ◽  
David C. Wharton
Keyword(s):  
Electron Transport ◽  
Transport System ◽  
Electron Transport System

Studies on the electron transport system

1959 ◽  
Vol 31 (2) ◽  
pp. 476-489 ◽  
Author(s):  
F.L. Crane ◽  
C. Widmer ◽  
R.L. Lester ◽  
Y. Hatefi ◽  
Wanda Fechner
Keyword(s):  
Electron Transport ◽  
Transport System ◽  
Electron Transport System
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