Cytochrome c Sorption-Desorption Effects on the External NADH Oxidation by Mitochondria

Lemeshko, Victor V.

doi:10.1074/jbc.m201002200

Cited by 28 publications

(20 citation statements)

References 31 publications

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“…A lower uncoupling efficiency of BTM-P1 in the sucrose medium could also be related to its electrostatic adsorption on mitochondrial membranes, as it is known for cytochrome c. Membrane adsorption of the positively charged cytochrome c decreased its electron transport activity in a low ionic strength incubation medium (49,63). Electrostatic binding of various polycations, including peptides, with anionic phospholipids of biomembranes has been suggested to induce the release of pro-apoptotic and other intermembrane proteins from mitochondria by a direct damage of the outer mitochondrial membrane or by opening of the mitochondrial permeability transition pore (64).…”

Section: Discussionmentioning

confidence: 99%

“…Respiration and Oxidative Phosphorylation-Respiration and oxidative phosphorylation of mitochondria were measured polarographically using the modified Cole-Parmer oxygen electrode (49) and the ColeParmer oxygen meter connected to the Linseis L250-E recorder. Mitochondria were added at concentration of 1 mg of protein/ml to the incubation medium containing 150 mM sucrose, 50 mM KCl, 50 M EGTA, 10 mM Hepes-Tris buffer, pH 7.2 (sucrose-KCl medium), or to the medium containing 250 mM sucrose, 50 M EGTA, 10 mM HepesTris buffer, pH 7.2 (sucrose medium), both supplemented with 5 mM succinate-Tris and 5 mM phosphate-Tris, pH 7.2.…”

Section: Methodsmentioning

confidence: 99%

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Mitochondria Permeabilization by a Novel Polycation Peptide BTM-P1

Lemeshko

Arias

Ordúz

2005

Journal of Biological Chemistry

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Bacillus thuringiensis subsp. medellin is known to produce the Cry11Bb protein of 94 kDa, which is toxic for mosquito larvae due to permeabilization of the plasma membrane of midgut epithelial cells. Earlier we found that a 2.8-kDa novel peptide BTM-P1, which was artificially synthesized taking into account the primary structure of Cry11Bb endotoxin, is active against several species of bacteria. In this work we show that BTM-P1 induces cyclosporin A-insensitive swelling of rat liver mitochondria in various salt solutions but not in the sucrose medium. Inorganic phosphate and Ca 2؉ significantly increased this effect of the peptide. The uncoupling action of BTM-P1 on oxidative phosphorylation was stronger in the potassiumcontaining media and correlated with a decrease of the inner membrane potential of mitochondria. In isotonic KNO 3 , KCl, or NH 4 NO 3 media, a complete drop of the inner membrane potential was observed at 1-2 g/ml of the peptide. The peptide-induced swelling was increased by energization of mitochondria in the potassium-containing media, but it was inhibited in the NaNO 3 , NH 4 NO 3 , and Tris-NO 3 media. All mitochondrial effects of the peptide were completely prevented by adding a single N-terminal tryptophan residue to the peptide sequence. We suggest a mechanism of membrane permeabilization that includes a transmembrane-and surface potential-dependent insertion of the polycation peptide into the lipid bilayer and its oligomerization leading to formation of ion channels and also to the mitochondrial permeability transition pore opening in a cyclosporin A-insensitive manner.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Mitochondria Permeabilization by a Novel Polycation Peptide BTM-P1

Lemeshko

Arias

Ordúz

2005

Journal of Biological Chemistry

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“…Cooled liver was homogenized in the medium containing 210 mM mannitol, 70 mM sucrose, 2.5 mM MgCl 2 , 1 mM EGTA-KOH, 0.3 mg/ml bovine serum albumin (BSA) (free fatty acids), 10 mM Hepes-KOH, pH 7.2, at 2-4°C. MgCl 2 was included in the homogenization medium to prevent cytochrome c adsorption on mitochondria (14), thus decreasing the respiration of the fraction of damaged mitochondria. After two washes with the medium containing 210 mM mannitol, 70 mM sucrose, 50 M EGTA-KOH, 0.3 mg/ml BSA, 10 mM Hepes-KOH, pH 7.2, mitochondria were finally resuspended in 1 ml of the same medium lacking BSA.…”

Section: Methodsmentioning

confidence: 99%

“…Measurement of Respiration-The oxygen consumption was measured using a Clark-type electrode as described earlier (14). Incubation medium was composed of 100 mM sucrose, 75 mM KCl, 10 mM potassium phosphate, 10 mM Hepes-KOH, pH 7.2 (SKPH medium).…”

Section: Methodsmentioning

confidence: 99%

Synergistic Inhibition of Mitochondrial Respiration by Anticancer Agent Erucylphosphohomocholine and Cyclosporin A

Lemeshko

Kugler

2007

Journal of Biological Chemistry

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Alkylphosphocholines are a new class of anticancer agents. The mechanisms by which these drugs display their antitumor activities are not known. In this work, we show that erucylphosphohomocholine, a new antineoplastic compound, significantly decreased ATP synthesis in isolated rat liver mitochondria at a concentration of 50 M or higher via permeabilization of the inner membrane. At a concentration of 25 M, it induced a moderate swelling of mitochondria, a slight decrease of the inner membrane potential, and an increase in state 4 respiration without an essential influence on state 3 respiration or the outer membrane permeability to cytochrome c. We found that cyclosporin A did not prevent mitochondrial swelling induced by 25-100 M erucylphosphohomocholine. Moreover, cyclosporin A induced a fast drop of the inner membrane potential in the presence of 25-50 M erucylphosphohomocholine that seems to be due to a strong synergistic inhibition of the respiratory activity. The ratio of uncoupled to state 3 respiration rates increased from 1.3 ؎ 0.1 with 25 M erucylphosphohomocholine and from 1.5 ؎ 0.1 with 1 M cyclosporin A to 4.5 ؎ 0.3 in the presence of both drugs. On the other hand, oligomycin or cyclosporin A protected certain cancer cell lines against erucylphosphohomocholine-induced apoptosis. This protection might be related to a prevention of cellular ATP hydrolysis by permeabilized mitochondria and to the inhibition of the classical permeability transition pore, respectively. Our findings provide new insight into the mechanisms by which these unusual alterations of mitochondria might be involved in anticancer activity of alkylphosphocholines.Alkylphosphocholines are a new class of antitumor agents, which target biomembranes and induce cancer cell apoptosis (1-3). Erucylphosphohomocholine (ErPC3), 2 one of the most effective alkylphosphocholines, has been shown to be a promising preclinical anticancer agent (4 -7). The precise mechanisms of antineoplastic activity of alkylphosphocholines are unknown. It has been found that they are working through p53-independent pathways (2, 8) involving mitochondrial alteration, cytochrome c release, and caspase-3 activation (9). Our previous studies have shown that the pro-apoptotic activity of ErPC3 is associated with an increased production of reactive oxygen species (10) and might be blocked by ligands of the peripheral-type benzodiazepine receptor (11), which is located in the outer membrane of mitochondria in close proximity to the voltage-dependent anion channel (12).In this work, we have found that in addition to pro-apoptotic activities, ErPC3 is also able to decrease ATP synthesis in isolated rat liver mitochondria. Our data showed that the ErPC3-mediated decrease of ATP synthesis involves a direct cyclosporin A (CsA)-insensitive permeabilization of the inner membrane. We have also discovered an unusual synergistic inhibition of ADP-dependent respiration of mitochondria in the presence of both CsA and ErPC3. The mechanism of this effect does not seem to be directly ...

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“…In the outer membrane of the mitochondria, including the brain mitochondria (Ito 1980), an NADH-cytochrome c reductase system is found, made up of a flavoprotein-5 and a cytochrome b 5 , facing the cytosol. Lemeshko (2001 and2002) showed in an exemplary way that in the presence of NADH and cytochrome c (both exogenous), the transport of electrons between the NADH-cytochrome c reductase system of the outer mitochondrial membrane (OMM) and complex IVof the inner mitochondrial membrane (IMM) is drastically activated when the OMM is permeabilized or has undergone a rupture (see Fig. 1 in the current Letter to the Editor).…”

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confidence: 99%

Mitochondria isolated from the striatum brain of acute paraquat treated rats exhibit a higher degree of oxidative phosphorylation coupling, which shows that they are not subject to energetic dysfunction upon acute paraquat administration

Rendón

2016

J Bioenerg Biomembr

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In the recent article by Czerniczyniec et al. (2015) entitled BImpairment of striatal mitochondrial function by acute paraquat poisoning^, published in the journal J Bioenerg Biomembr 2015; 47(5): 395-408, various aspects of the bioenergetics of mitochondria isolated from the striatum and the cerebral cortex of the brain during acute paraquat toxicity have been investigated. The bioenergetic aspects studied in this investigation are basically fall into two large categories: i) the determination of the state 4 mitochondrial respiration (state 4), the state 3 mitochondrial respiration (state 3), and the respiratory control ratio (RC); and ii) the determination of the activity of mitochondrial complex I-III, mitochondrial complex II-III, and mitochondrial complex IV. On the basis of all of these results, Czerniczyniec et al. (2015) conclude the existence of a paraquat dysfunction in the bioenergetics of mitochondria isolated from the striatum of the brain. However, both a part of the methodology used and the interpretation of the above-mentioned results obtained exhibit serious fallacies and contradictions that do not support the conclusion of the authors with respect to a negative alteration of the bioenergetics of the striatum mitochondria upon acute paraquat administration.The data of Fig. 2a-KCN-sensitive respiration (in the article by Czerniczyniec et al. 2015) correspond to the consumption of oxygen only by the striatum mitochondria, and do not include that which takes place in the process of paraquat redox cycling. The authors consider the decreases shown in this Fig. 2a, for paraquat state 4 as well as for paraquat state 3 as strong evidence of a dysfunction of the bioenergetics of the mitochondria isolated from the striatum of the brain upon acute paraquat administration. But these data do not reflect a mitochondrial dysfunction. The RC is the fundamental parameter that indicates the energetic coupling of the mitochondria, and the researchers Czerniczyniec et al. consider that to be the case, writing (see page 400, first paragraph): BThe respiratory control ratio (the most sensitive indicator of mitochondrial oxidative phosphorylation coupling).^Nevertheless, these researchers do not report the RC calculated on the basis of their data presented in Fig. 2a (KCN-sensitive respiration). On calculating the RC (RC = state 3/state 4) on the basis of these data, (Fig. 2a of the article by Czerniczyniec et al. (2015)), an average value for the control RC of 5.9 and for the paraquat RC of 11.0 is obtained. These values show something surprising: the paraquat striatum brain mitochondria exhibit a greater degree of oxidative phosphorylation coupling, indicating that they are no subject to a dysfunction of their energetic state upon acute paraquat administration. In the same way, it is curious to observe (in the Bapparent^parameters of the mitochondrial respiration shown in Table 1 of the article by Czerniczyniec et al. (2015)) for the RC of the cerebral cortex mitochondria (control RC = 4.6 ± 0.2 and paraquat RC = 5....

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Cytochrome c Sorption-Desorption Effects on the External NADH Oxidation by Mitochondria

Cited by 28 publications

References 31 publications

Mitochondria Permeabilization by a Novel Polycation Peptide BTM-P1

Mitochondria Permeabilization by a Novel Polycation Peptide BTM-P1

Synergistic Inhibition of Mitochondrial Respiration by Anticancer Agent Erucylphosphohomocholine and Cyclosporin A

Mitochondria isolated from the striatum brain of acute paraquat treated rats exhibit a higher degree of oxidative phosphorylation coupling, which shows that they are not subject to energetic dysfunction upon acute paraquat administration

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