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Iliuza R. Iaubasarova, Alexander M. Firsov, Ljudmila S. Khailova, Nadejda K. Davydova, Elena A. Kotova, Galina A. Korshunova, Yuri N. Antonenko
Carbonylcyanide-2-nitro-4-azidophenylhydrazone
(an azido derivative of the mitochondrial uncoupler CCCP) as a photosensitive
protonophore
Abstract
Abstract. An azido derivative of the
mitochondrial uncoupler carbonyl cyanide-m-chlorophenylhydrazone (CCCP), namely
carbonyl cyanide-2-nitro-4-azidophenylhydrazone (N3CCP), has
previously been used to study the binding sites of uncouplers on mitochondrial
proteins. In this study, we compared the protonophore activity of N3CCP
and CCCP on an artificial bilayer lipid membrane (BLM) and the uncoupling
activity of these compounds on isolated rat liver mitochondria. Both compounds
induced electrical current through the BLM at micromolar concentrations and
uncoupled mitochondria at submicromolar concentrations. Both protonophoric and
uncoupling activities of N3CCP were effectively inhibited by UV
light, whereas CCCP was light-insensitive. These results indicate that N3CCP
is modified by UV light to form products incapable of hydrogen ion transport
across artificial or natural membranes.
Key words: uncoupler,
protonophore, bilayer lipid membrane, mitochondria, phototransformations
Copyright (C) Chemistry Dept., Moscow State University, 2002
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