Mitochondrial respiratory chain-dependent generation of superoxide anion and its release into the intermembrane space

2001 ◽  
Vol 353 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Derick HAN ◽  
Everett WILLIAMS ◽  
Enrique CADENAS
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Respiratory Chain ◽  
Superoxide Anion ◽  
Complex Iii ◽  
Spin Adduct ◽  
Intermembrane Space ◽  
Epr Signal ◽  
Mitochondrial Respiratory

It has been generally accepted that superoxide anion generated by the mitochondrial respiratory transport chain are vectorially released into the mitochondrial matrix, where they are converted to hydrogen peroxide through the catalytic action of Mn-superoxide dismutase. Release of superoxide anion into the intermembrane space is a controversial topic, partly unresolved by the reaction of superoxide anion with cytochrome c, which faces the intermembrane space and is present in this compartment at a high concentration. This study was aimed at assessing the topological site(s) of release of superoxide anion during respiratory chain activity. To address this issue, mitoplasts were prepared from isolated mitochondria by digitonin treatment to remove portions of the outer membrane along with portions of cytochrome c. EPR analysis in conjunction with spin traps of antimycin-supplemented mitoplasts revealed the formation of a spin adduct of superoxide anion. The EPR signal was (i) abrogated by superoxide dismutase, (ii) decreased competitively by exogenous ferricytochrome c and (iii) broadened by the membrane-impermeable spin-broadening agent chromium trioxalate. These results confirm the production and release of superoxide anion towards the cytosolic side of the inner mitochondrial membrane. In addition, co-treatment of mitoplasts with myxothiazol and antimycin A, resulting in an inhibition of the oxidation of ubiquinol to ubisemiquinone, abolished the EPR signal, thus suggesting that ubisemiquinone autoxidation at the outer site of the complex-III ubiquinone pool is a pathway for superoxide anion formation and subsequent release into the intermembrane space. The generation of superoxide anion towards the intermembrane space requires consideration of the mitochondrial steady-state values for superoxide anion and hydrogen peroxide, the decay pathways of these oxidants in this compartment and the implications of these processes for cytosolic events.

GSH transport in mitochondria: defense against TNF-induced oxidative stress and alcohol-induced defect

1997 ◽  
Vol 273 (1) ◽  
pp. G7-G17 ◽  
Author(s):  
J. C. Fernandez-Checa ◽  
N. Kaplowitz ◽  
C. Garcia-Ruiz ◽  
A. Colell ◽  
M. Miranda ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Plasma Membrane ◽  
Molecular Oxygen ◽  
Respiratory Chain ◽  
Superoxide Anion ◽  
Complex Iii ◽  
Contributory Factor ◽  
Xenopus Laevis Oocytes ◽  
Mitochondrial Matrix

Mitochondria generate reactive oxygen species (ROS) as byproducts of molecular oxygen consumption in the electron transport chain. Most cellular oxygen is consumed in the cytochrome-c oxidase complex of the respiratory chain, which does not generate reactive species. The ubiquinone pool of complex III of respiration is the major site within the respiratory chain that generates superoxide anion as a result of a single electron transfer to molecular oxygen. Superoxide anion and hydrogen peroxide, derived from the former by superoxide dismutase, are precursor of hydroxyl radical through the participation of transition metals. Glutathione (GSH) in mitochondria is the only defense available to metabolize hydrogen peroxide. A small fraction of the total cellular GSH pool is sequestered in mitochondria by the action of a carrier that transports GSH from the cytosol to the mitochondrial matrix. Mitochondria are not only one of the main cellular sources of ROS, they also are a key target of ROS. Mitochondria are subcellular targets of cytokines, especially tumor necrosis factor (TNF); depletion of GSH in this organelle renders the cell more susceptible to oxidative stress originating in mitochondria. Ceramide generated during TNF signaling leads to increased production of ROS in mitochondria. Chronic ethanol-fed hepatocytes are selectively depleted of GSH in mitochondria due to a defective operation of the carrier responsible for transport of GSH from the cytosol into the mitochondrial matrix. Under these conditions, limitation of the mitochondrial GSH pool represents a critical contributory factor that sensitizes alcoholic hepatocytes to the prooxidant effects of cytokines and prooxidants generated by oxidative metabolism of ethanol. S-adenosyl-L-methionine prevents development of the ethanol-induced defect. The mitochondrial GSH carrier has been functionally expressed in Xenopus laevis oocytes microinjected with mRNA from rat liver. This critical carrier displays functional characteristics distinct from other plasma membrane GSH carriers, such as its ATP dependency, inhibitor specificity, and the size class of mRNA that encode the corresponding carrier, suggesting that the mitochondrial carrier of GSH is a gene product distinct from the plasma membrane transporters.

scholarly journals The disulfide relay system of mitochondria is connected to the respiratory chain

2007 ◽  
Vol 179 (3) ◽  
pp. 389-395 ◽  
Author(s):  
Karl Bihlmaier ◽  
Nikola Mesecke ◽  
Nadia Terziyska ◽  
Melanie Bien ◽  
Kai Hell ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transport ◽  
Cytochrome C ◽  
Respiratory Chain ◽  
Disulfide Bonds ◽  
Electron Transport Chain ◽  
Intermembrane Space ◽  
Sulfhydryl Oxidase ◽  
Relay System ◽  
Transport Chain

All proteins of the intermembrane space of mitochondria are encoded by nuclear genes and synthesized in the cytosol. Many of these proteins lack presequences but are imported into mitochondria in an oxidation-driven process that relies on the activity of Mia40 and Erv1. Both factors form a disulfide relay system in which Mia40 functions as a receptor that transiently interacts with incoming polypeptides via disulfide bonds. Erv1 is a sulfhydryl oxidase that oxidizes and activates Mia40, but it has remained unclear how Erv1 itself is oxidized. Here, we show that Erv1 passes its electrons on to molecular oxygen via interaction with cytochrome c and cytochrome c oxidase. This connection to the respiratory chain increases the efficient oxidation of the relay system in mitochondria and prevents the formation of toxic hydrogen peroxide. Thus, analogous to the system in the bacterial periplasm, the disulfide relay in the intermembrane space is connected to the electron transport chain of the inner membrane.

scholarly journals Specific requirements of nonbilayer phospholipids in mitochondrial respiratory chain function and formation

2016 ◽  
Vol 27 (14) ◽  
pp. 2161-2171 ◽  
Author(s):  
Charli D. Baker ◽  
Writoban Basu Ball ◽  
Erin N. Pryce ◽  
Vishal M. Gohil
Keyword(s):  
Respiratory Chain ◽  
Mitochondrial Membrane ◽  
Phospholipid Composition ◽  
Mitochondrial Respiratory Chain ◽  
Complex Iii ◽  
Specific Requirement ◽  
Transport Pathway ◽  
Contact Sites ◽  
Yeast Mutants ◽  
Mitochondrial Respiratory

Mitochondrial membrane phospholipid composition affects mitochondrial function by influencing the assembly of the mitochondrial respiratory chain (MRC) complexes into supercomplexes. For example, the loss of cardiolipin (CL), a signature non–bilayer-forming phospholipid of mitochondria, results in disruption of MRC supercomplexes. However, the functions of the most abundant mitochondrial phospholipids, bilayer-forming phosphatidylcholine (PC) and non–bilayer-forming phosphatidylethanolamine (PE), are not clearly defined. Using yeast mutants of PE and PC biosynthetic pathways, we show a specific requirement for mitochondrial PE in MRC complex III and IV activities but not for their formation, whereas loss of PC does not affect MRC function or formation. Unlike CL, mitochondrial PE or PC is not required for MRC supercomplex formation, emphasizing the specific requirement of CL in supercomplex assembly. Of interest, PE biosynthesized in the endoplasmic reticulum (ER) can functionally substitute for the lack of mitochondrial PE biosynthesis, suggesting the existence of PE transport pathway from ER to mitochondria. To understand the mechanism of PE transport, we disrupted ER–mitochondrial contact sites formed by the ERMES complex and found that, although not essential for PE transport, ERMES facilitates the efficient rescue of mitochondrial PE deficiency. Our work highlights specific roles of non–bilayer-forming phospholipids in MRC function and formation.

scholarly journals Macrophage variants in oxygen metabolism.

1980 ◽  
Vol 152 (4) ◽  
pp. 808-822 ◽  
Author(s):  
G Damiani ◽  
C Kiyotaki ◽  
W Soeller ◽  
M Sasada ◽  
J Peisach ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cytochrome C ◽  
Superoxide Anion ◽  
Oxygen Metabolism ◽  
Hexose Monophosphate ◽  
Phagocytic Cells ◽  
Form Complex ◽  
Hexose Monophosphate Shunt ◽  
Cytochrome C Reduction ◽  
Generate Superoxide Anion

Whereas phagocytic cells from normal individuals have the capacity to kill ingested bacteria and parasites, those from patients with several uncommon genetic deficiency diseases are known to be defective in bactericidal activity. Studies on neutrophils of these patients have revealed fundamental defects in their ability to reduce molecular oxygen and metabolize it to superoxide anion, hydrogen peroxide, and oxygen radicals. In the present experiments, we describe a clone of a continuous murine macrophage-like cell line, J774.16, that, upon appropriate stimulation, activates the hexose monophosphate shunt, and produces superoxide anion and hydrogen peroxide. With nitroblue tetrazolium to select against cells capable of being stimulated by phorbol myristate acetate to reduce the dye to polymer--formazan--which is toxic fot cells, we have selected for variants that are defective in oxygen metabolism. Four of these subclones have been characterized and found to be lacking in the ability (a) to generate superoxide anion, as measured by cytochrome c reduction; (b) to produce hydrogen peroxide, as measured by the ability to form complex I with cytochrome c peroxidase; and (c) to be stimulated to oxidize glucose via the hexose monophosphate shunt. These variants appear to represent a useful model for studying the molecular basis for macrophage cytocidal activity.

Succinimidyl oleate, established inhibitor of CD36/FAT translocase inhibits complex III of mitochondrial respiratory chain

2010 ◽  
Vol 391 (3) ◽  
pp. 1348-1351 ◽  
Author(s):  
Zdeněk Drahota ◽  
Marek Vrbacký ◽  
Hana Nůsková ◽  
Ludmila Kazdová ◽  
Václav Zídek ◽  
...  
Keyword(s):  
Respiratory Chain ◽  
Mitochondrial Respiratory Chain ◽  
Complex Iii ◽  
Mitochondrial Respiratory

Carbon Monoxide Specifically Inhibits Cytochrome C Oxidase of Human Mitochondrial Respiratory Chain

2003 ◽  
Vol 93 (3) ◽  
pp. 142-146 ◽  
Author(s):  
Jose-Ramon Alonso ◽  
Francesc Cardellach ◽  
Sònia López ◽  
Jordi Casademont ◽  
Òscar Miró
Keyword(s):  
Carbon Monoxide ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Respiratory Chain ◽  
Mitochondrial Respiratory Chain ◽  
Mitochondrial Respiratory

Novel Mycotoxin fromAcremonium exuviarumIs a Powerful Inhibitor of the Mitochondrial Respiratory Chain Complex III

2009 ◽  
Vol 22 (3) ◽  
pp. 565-573 ◽  
Author(s):  
Alexey G. Kruglov ◽  
Maria A. Andersson ◽  
Raimo Mikkola ◽  
Merja Roivainen ◽  
Laszlo Kredics ◽  
...  
Keyword(s):  
Respiratory Chain ◽  
Chain Complex ◽  
Mitochondrial Respiratory Chain ◽  
Complex Iii ◽  
Respiratory Chain Complex ◽  
Mitochondrial Respiratory Chain Complex ◽  
Mitochondrial Respiratory

Haematoporphyrin enhances the peroxidase activity of haemoglobin

2000 ◽  
Vol 04 (02) ◽  
pp. 168-174 ◽  
Author(s):  
SUSMITA SIL ◽  
MANOJ KAR ◽  
ABHAY SANKAR CHAKRABORTI
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Conformational Change ◽  
Anticancer Drugs ◽  
Peroxidase Activity ◽  
Superoxide Anion ◽  
Spectrophotometric Study ◽  
Stoichiometric Ratio ◽  
Mediated Oxidation

The effect of haematoporphyrin, a component of some of the widely used anticancer drugs, on the peroxidase activity of haemoglobin has been studied. Haematoporphyrin increases the haemoglobin-catalysed hydrogen peroxide-mediated oxidation of o-dianisidine or NADH. Spectrophotometric study reveals that an interaction occurs between haemoglobin and haematoporphyrin which leads to a conformational change of the protein. The extent of enhanced peroxidase activity as well as conformational change of the protein vary in a positive manner with the stoichiometric ratio of haematoporphyrin/haemoglobin. An increase in the peroxidase activity of haemoglobin was also observed in the presence of superoxide dismutase, which catalysed the removal of superoxide anion generated during autoxidation of haemoglobin. Possible mechanisms underlying the relation between the conformational change of haemoglobin due to its interaction with haematoporphyrin and the enhanced peroxidase activity are discussed.

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