title: Effect of surface-potential modulators on the opening of lipid pores in liposomal and mitochondrial inner membranes induced by palmitate and calcium ions.
abstract: The effect of surface-potential modulators on palmitate/Ca2+-induced formation of lipid pores was studied in liposomal and inner mitochondrial membranes. Pore formation was monitored by sulforhodamine B release from liposomes and swelling of mitochondria. ζ-potential in liposomes was determined from electrophoretic mobility. Replacement of sucrose as the osmotic agent with KCl decreased negative ζ-potential in liposomes and increased resistance of both mitochondria and liposomes to the pore inducers, palmitic acid, and Ca2+. Micromolar Mg2+ also inhibited palmitate/Ca2+-induced permeabilization of liposomes. The rate of palmitate/Ca2+-induced, cyclosporin A-insensitive swelling of mitochondria increased 22% upon increasing pH from 7.0 to 7.8. At below the critical micelle concentration, the cationic detergent cetyltrimethylammonium bromide (10 μM) and the anionic surfactant sodium dodecylsulfate (10-50 μM) made the ζ-potential less and more negative, respectively, and inhibited and stimulated opening of mitochondrial palmitate/Ca2+-induced lipid pores. Taken together, the findings indicate that surface potential regulates palmitate/Ca2+-induced lipid pore opening.
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, Institutskaya 3, Pushchino, Moscow region 142290, Russia. Electronic address: bekonik@gmail.com.
authors.forename: Konstantin N
authors.initials: KN
authors.lastname: Belosludtsev
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, Institutskaya 3, Pushchino, Moscow region 142290, Russia.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Belosludtseva
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, Institutskaya 3, Pushchino, Moscow region 142290, Russia.
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Agafonov
authors.affiliation: Institute of Cell Biophysics RAS, Institutskaya 3, Pushchino, Moscow region 142290, Russia.
authors.forename: Nikita V
authors.initials: NV
authors.lastname: Penkov
authors.affiliation: Mari State University, pr. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia.
authors.forename: Victor N
authors.initials: VN
authors.lastname: Samartsev
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, Institutskaya 3, Pushchino, Moscow region 142290, Russia; Center for Cell Death, Injury & Regeneration, Departments of Drug Discovery & Biomedical Sciences and Biochemistry & Molecular Biology , Medical University of South Carolina, DD504 Drug Discovery Building, 70 President Street, MSC 140, Charleston, SC 29425, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Lemasters
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, Institutskaya 3, Pushchino, Moscow region 142290, Russia.
authors.forename: Galina D
authors.initials: GD
authors.lastname: Mironova
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D007477:Ions; D008081:Liposomes / Q000737:chemistry*; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000502:physiology*; D010168:Palmitates / Q000737:chemistry / Q000494:pharmacology*; D016062:Porosity / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D055672:Static Electricity; D013499:Surface Properties / Q000187:drug effects
chemical_list: D007477:Ions; D008081:Liposomes; D010168:Palmitates; D002118:Calcium
keywords: Calcium; Fatty acids; Lipid pores; Liposomes; Mitochondria; Surface membrane potential