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12 results on '"Mokhova, Elena N."'

5. A cytochrome c mutant with high electron transfer and antioxidant activities but devoid of apoptogenic effect

Author

Abdullaev, Ziedulla Kh, Bodrova, Marina E, Chernyak, Boris V, Dolgikh, Dmitry A, Kluck, Ruth M, Pereverzev, Mikhail O, Arseniev, Alexander S, Efremov, Roman G, Kirpichnikov, Mikhail P, Mokhova, Elena N, Newmeyer, Donald D, Roder, Heinrich, and Skulachev, Vladimir P

Subjects
Sequence Homology, Amino Acid, Apoptosis, Cytochrome c Group, Mitochondria, Liver, Saccharomyces cerevisiae, Cell Biology, Biochemistry, Antioxidants, Protein Structure, Secondary, Recombinant Proteins, Rats, Kinetics, Xenopus laevis, Amino Acid Substitution, Caspases, Mutagenesis, Site-Directed, Animals, Amino Acid Sequence, Horses, Sequence Alignment, Molecular Biology, Research Article
Abstract

A cytochrome c mutant lacking apoptogenic function but competent in electron transfer and antioxidant activities has been constructed. To this end, mutant species of horse and yeast cytochromes c with substitutions in the N-terminal α-helix or position 72 were obtained. It was found that yeast cytochrome c was much less effective than the horse protein in activating respiration of rat liver mitoplasts deficient in endogenous cytochrome c as well as in inhibition of H2O2 production by the initial segment of the respiratory chain of intact rat heart mitochondria. The major role in the difference between the horse and yeast proteins was shown to be played by the amino acid residue in position 4 (glutamate in horse, and lysine in yeast; horse protein numbering). A mutant of the yeast cytochrome c containing K4E and some other ‘horse’ modifications in the N-terminal α-helix, proved to be (i) much more active in electron transfer and antioxidant activity than the wild-type yeast cytochrome c and (ii), like the yeast cytochrome c, inactive in caspase stimulation, even if added in 400-fold excess compared with the horse protein. Thus this mutant seems to be a good candidate for knock-in studies of the role of cytochrome c-mediated apoptosis, in contrast with the horse K72R, K72G, K72L and K72A mutant cytochromes that at low concentrations were less active in apoptosis than the wild-type, but were quite active when the concentrations were increased by a factor of 2–12.

Published
2002
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6. Penetrating cation/fatty acid anion pair as a mitochondria-targeted protonophore

Author

Severin, Fedor F., primary, Severina, Inna I., additional, Antonenko, Yury N., additional, Rokitskaya, Tatiana I., additional, Cherepanov, Dmitry A., additional, Mokhova, Elena N., additional, Vyssokikh, Mikhail Yu., additional, Pustovidko, Antonina V., additional, Markova, Olga V., additional, Yaguzhinsky, Lev S., additional, Korshunova, Galina A., additional, Sumbatyan, Nataliya V., additional, Skulachev, Maxim V., additional, and Skulachev, Vladimir P., additional

Published
2009
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10. The ATP/ADP-antiporter is involved in the uncoupling effect of fatty acids on mitochondria.

Author

Andreyev, Alexander Yu., Bondareva, Tatjana O., Dedukhova, Vera I., Mokhova, Elena N., Skulachev, Vladimir P., Tsofina, Lilya M., Volkov, Nickolaj I., and Vygodina, Tatjana V.

Subjects
ENZYME inhibitors, ANTIFIBRINOLYTIC agents, ANTIMETABOLITES, CYTOCHROMES, CELL membranes, RESPIRATION
Abstract

The ATP/ADP-antiporter inhibitors and the substrate ADP suppress the uncoupling effect induced by low (10-20 µM) concentrations of palmitate in mitochondria from skeletal muscle and liver. The inhibitors and ADP are found to (a) inhibit the palmitate-stimulated respiration in the controlled state and (b) increase the membrane potential lowered by palmitate. The degree of efficiency decreases in the order: carboxyatractylate (CAtr) > ADP > bongkrekic acid, atractylate. GDP is ineffective, Mg. ADP is of much smaller effect, whereas ATP is effective at much higher concentration than is ADP. Inhibitor concentrations, which maximally suppress the palmitate-stimulated respiration, correspond to those needed for arresting the state 3 respiration. The extent of the CAtr-sensitive stimulation of respiration by palmitate has been found to decrease with an increase in palmitate concentration. Stimulation of the controlled respiration by p-trifluoromethoxycarbonylcyanide phenylhydrozone (FCCP) and gramicidin D at any concentrations of these uncouplers is CAtr-insensitive, whereas that caused by a low concentrations of 2,4-dinitrophenol and dodecyl sulfate is inhibited by CAtr. The above effect of palmitate develops immediately after addition of the fatty acid. It is resistant to EGTA as well as to inhibitors of phospholipase (nupercain) and of lipid peroxidation (ionol). Moreover, palmitate accelerates spontaneous release of the respiratory control, developing in rat liver rnitochondria under certain conditions. This effect takes several minutes, being sensitive to EGTA, nupercain and ionol. Like the fast uncoupling, this slow effect is inhibited by ADP but CAtr and atractylate are stimulatory rather than inhibitory. In artificial planar phospholipid membrane, palmitate does not increase the membrane conductance, FCCP increases it strongly and dinitrophenol only slightly. In cytochrome oxidase proteoliposomes, FCCP, gramicidin and dinitrophenol (less effectively) lower, whereas palmitate enhances the cytochrome-oxidase-generated membrane potential. In this system, monensin substitutes for palmitate. It is concluded that the ATP/ADP antiporter is somehow involved in the uncoupling effect caused by low concentrations of palmitate and, partially, of dinitrophenol, whereas uncoupling produced by FCCP and gramicidin is due to their action on the phospholipid part of the mitochondrial membrane. A possible mechanism of this effect is discussed. [ABSTRACT FROM AUTHOR]

Published
1989
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