Electrogenic proton transport across lipid bilayer membranes mediated by cationic derivatives of rhodamine 19: comparison with anionic protonophores
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Protonophores can be considered as candidates for anti-obesity drugs and tools to prevent excessive reactive oxygen species production in mitochondria by means of a limited decrease in the mitochondrial potential. Experimentally used protonophores are weak acids that can carry protons across a membrane in a neutral (protonated) form, and they come back in an anionic (deprotonated) form. A cationic derivative of rhodamine 19 and plastoquinone (SkQR1) was recently shown to possess uncoupling activity in mitochondria and in intact cells. In this article, we studied the mechanism of action of SkQR1 and its plastoquinone-lacking analog (C12R1) on a planar bilayer lipid membrane by applying voltage jumps. The steady-state current was proportional to the C12R1 concentration in a manner as if the monomeric form of the carrier were operative. As predicted by the carrier model, at high pH, when rhodamines were mainly deprotonated, the current changed immediately following a jump in the applied potential and then remained constant. By contrast, at low pH, the current relaxed from an initially high value to a lower value since the protonated carrier cations were redistributed in the membrane. An inverse pH dependence was revealed with the anionic protonophore CCCP. The dependence of the SkQR1 protonophorous activity on voltage exhibited an increase at high voltages, an effect that might facilitate mild (self-limited) uncoupling of mitochondria.
KeywordsBilayer lipid membrane Protonophore Uncoupling activity Dipole potential SkQR1
The authors thank Dr. Elena Kotova for valuable comments. This work was supported in part by the Russian Foundation for Basic Research grant 12-04-00199 and the Institute of Mitoengineering, Lomonosov Moscow State University.
- Antonenko YN, Avetisyan AV, Bakeeva LE, Chernyak BV, Chertkov VA, Domnina LV, Ivanova OYu, Izyumov DS, Khailova LS, Klishin SS, Korshunov SS, Korshunova GA, Kovaleva NA, Lyamzaev KG, Muntyan MS, Nepryakhina OK, Pashkovskaya AA, Pletjushkina OY, Pustovidko AV, Rokitskaya TI, Ruuge EK, Saprunova VB, Severina II, Simonyan RA, Skulachev IV, Skulachev MV, Sumbatyan NV, Sviryaeva IV, Tashlitsky VN, Tikhomirova NK, Vassiliev YM, Vyssokikh MY, Yaguzhinsky LS, Skulachev VP (2008) Mitochondria-targeted derivative of plastoquinone as tool to interrupt execution of an aging program. 1. Cationic plastoquinone derivatives: synthesis and in vitro studies. Biochemistry (Mosc) 73:1273–1287CrossRefGoogle Scholar
- Antonenko YN, Avetisyan AV, Cherepanov DA, Knorre DA, Korshunova GA, Markova OV, Ojovan SM, Perevoshchikova IV, Pustovidko AV, Rokitskaya TI, Severina II, Simonyan RA, Smirnova EA, Sobko AA, Sumbatyan NV, Severin FF, Skulachev VP (2011) Derivatives of rhodamine 19 as mild mitochondria-targeted cationic uncouplers. J Biol Chem 286:17831–17840PubMedCrossRefGoogle Scholar
- Mueller P, Rudin DO, Tien HT, Wescott WC (1963) Methods for the formation of single bimolecular lipid membranes in aqueous solution. J Phys Chem 67:534–535Google Scholar
- Nagamune H, Fukushima Y, Takada J, Yoshida K, Unami A, Shimooka T, Terada H (1993) The lipophilic weak base (Z)-5-methyl-2-[2-(1-naphthyl)ethenyl]-4-piperidinopyridine (AU-1421) is a potent protonophore type cationic uncoupler of oxidative phosphorylation in mitochondria. Biochim Biophys Acta 1141:231–237PubMedCrossRefGoogle Scholar
- Severin FF, Severina II, Antonenko YN, Rokitskaya TI, Cherepanov DA, Mokhova EN, Vyssokikh MY, Pustovidko AV, Markova OV, Yaguzhinsky LS, Korshunova GA, Sumbatyan NV, Skulachev MV, Skulachev VP (2010) Penetrating cation/fatty acid anion pair as a mitochondria-targeted protonophore. Proc Natl Acad Sci USA 107:663–668PubMedCrossRefGoogle Scholar