title: Penetrating cations enhance uncoupling activity of anionic protonophores in mitochondria.
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.
authors.affiliation: M.V. Lomonosov Moscow State University, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow, Russia. antonen@genebee.msu.ru
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Antonenko
authors.forename: Ljudmila S
authors.initials: LS
authors.lastname: Khailova
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Knorre
authors.forename: Olga V
authors.initials: OV
authors.lastname: Markova
authors.forename: Tatyana I
authors.initials: TI
authors.lastname: Rokitskaya
authors.forename: Tatyana M
authors.initials: TM
authors.lastname: Ilyasova
authors.forename: Inna I
authors.initials: II
authors.lastname: Severina
authors.forename: Elena A
authors.initials: EA
authors.lastname: Kotova
authors.forename: Yulia E
authors.initials: YE
authors.lastname: Karavaeva
authors.forename: Anastasia S
authors.initials: AS
authors.lastname: Prikhodko
authors.forename: Fedor F
authors.initials: FF
authors.lastname: Severin
authors.forename: Vladimir P
authors.initials: VP
authors.lastname: Skulachev
mesh_terms: D019297:2,4-Dinitrophenol / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002412:Cations; D005452:Fluoresceins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D008930:Mitochondria, Liver / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D010971:Plastoquinone / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism; D061209:Proton Ionophores / Q000494:pharmacology*; D011522:Protons; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism
chemical_list: C532038:10-(6'-plastoquinonyl)decyltriphenylphosphonium; D002412:Cations; D005452:Fluoresceins; D008051:Lipid Bilayers; D008081:Liposomes; D009943:Organophosphorus Compounds; D061209:Proton Ionophores; D011522:Protons; C001115:dodecyltriphenylphosphonium; C024098:6-carboxyfluorescein; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D010971:Plastoquinone; D019297:2,4-Dinitrophenol