Effect of Cysteinesulfinate on Fatty Acid-Dependent Uncoupling: Modulation of Recoupling by Substrates of the Aspartate/Glutamate Antiporter and Diethyl Pyrocarbonate

V. N. Samartsev^1,2 and E. N. Mokhova¹

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (7-095) 939-31-81.

²To whom correspondence should be addressed.

Submitted October 21, 1996; revision submitted January 30, 1997.

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The action of cysteinesulfinate, the substrate of the aspartate/glutamate antiporter on the palmitate-induced uncoupling in rat liver mitochondria and the recoupling effect of glutamate, aspartate, and diethyl pyrocarbonate was studied. In the presence of palmitate and an inhibitor of the ADP/ATP-antiporter carboxyatractylate, cysteinesulfinate exerted a relatively week recoupling effect. However, it significantly decreased the recoupling action of glutamate, aspartate, and diethyl pyrocarbonate. In the presence of cysteinesulfinate, these compounds caused recoupling at higher concentrations. The data show that the recoupling action of glutamate, aspartate, and diethyl pyrocarbonate is due to their interaction with the aspartate/glutamate antiporter. The data also confirm the suggestion that this anion carrier is involved in the uncoupling action of fatty acids.

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KEY WORDS: uncouplers, fatty acids, aspartate/glutamate antiporter, glutamate, aspartate, diethyl pyrocarbonate, cysteinesulfinic acid, liver mitochondria.

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