Penetrating cations enhance uncoupling activity of anionic protonophores in mitochondria

PLoS One. 2013 Apr 23;8(4):e61902. doi: 10.1371/journal.pone.0061902. Print 2013.

Abstract

Protonophorous uncouplers causing a partial decrease in mitochondrial membrane potential are promising candidates for therapeutic applications. Here we showed that hydrophobic penetrating cations specifically targeted to mitochondria in a membrane potential-driven fashion increased proton-translocating activity of the anionic uncouplers 2,4-dinitrophenol (DNP) and carbonylcyanide-p-trifluorophenylhydrazone (FCCP). In planar bilayer lipid membranes (BLM) separating two compartments with different pH values, DNP-mediated diffusion potential of H(+) ions was enhanced in the presence of dodecyltriphenylphosphonium cation (C12TPP). The mitochondria-targeted penetrating cations strongly increased DNP- and carbonylcyanide m-chlorophenylhydrazone (CCCP)-mediated steady-state current through BLM when a transmembrane electrical potential difference was applied. Carboxyfluorescein efflux from liposomes initiated by the plastoquinone-containing penetrating cation SkQ1 was inhibited by both DNP and FCCP. Formation of complexes between the cation and CCCP was observed spectophotometrically. In contrast to the less hydrophobic tetraphenylphosphonium cation (TPP), SkQ1 and C12TPP promoted the uncoupling action of DNP and FCCP on isolated mitochondria. C12TPP and FCCP exhibited a synergistic effect decreasing the membrane potential of mitochondria in yeast cells. The stimulating action of penetrating cations on the protonophore-mediated uncoupling is assumed to be useful for medical applications of low (non-toxic) concentrations of protonophores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,4-Dinitrophenol / pharmacology
  • Animals
  • Biological Transport / drug effects
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
  • Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / pharmacology
  • Cations
  • Fluoresceins / metabolism
  • Hydrogen-Ion Concentration
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism
  • Liposomes / chemistry
  • Liposomes / metabolism
  • Membrane Potential, Mitochondrial / drug effects
  • Mitochondria / chemistry
  • Mitochondria / drug effects*
  • Mitochondria / metabolism
  • Mitochondria, Liver / chemistry
  • Mitochondria, Liver / drug effects*
  • Mitochondria, Liver / metabolism
  • Organophosphorus Compounds / pharmacology*
  • Plastoquinone / analogs & derivatives
  • Plastoquinone / antagonists & inhibitors
  • Plastoquinone / metabolism
  • Proton Ionophores / pharmacology*
  • Protons*
  • Rats
  • Saccharomyces cerevisiae / chemistry
  • Saccharomyces cerevisiae / drug effects
  • Saccharomyces cerevisiae / metabolism

Substances

  • 10-(6'-plastoquinonyl)decyltriphenylphosphonium
  • Cations
  • Fluoresceins
  • Lipid Bilayers
  • Liposomes
  • Organophosphorus Compounds
  • Proton Ionophores
  • Protons
  • dodecyltriphenylphosphonium
  • 6-carboxyfluorescein
  • Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone
  • Plastoquinone
  • 2,4-Dinitrophenol

Grant support

This work was supported in part by the Russian Foundation for Basic Research grant 12-04-00199 and the Institute of Mitoengineering, Moscow State University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.