title: Ca(2+)-dependent permeabilization of mitochondria and liposomes by palmitic and oleic acids: a comparative study.
abstract: In the present work, we examine and compare the effects of saturated (palmitic) and unsaturated (oleic) fatty acids in relation to their ability to cause the Ca(2+)-dependent membrane permeabilization. The results obtained can be summarized as follows. (1) Oleic acid (OA) permeabilizes liposomal membranes at much higher concentrations of Ca(2+) than palmitic acid (PA): 1mM versus 100μM respectively. (2) The OA/Ca(2+)-induced permeabilization of liposomes is not accompanied by changes in the phase state of lipid bilayer, in contrast to what is observed with PA and Ca(2+). (3) The addition of Ca(2+) to the PA-containing vesicles does not change their size; in the case of OA, it leads to the appearance of larger and smaller vesicles, with larger vesicles dominating. This can be interpreted as a result of fusion and fission of liposomes. (4) Like PA, OA is able to induce a Ca(2+)-dependent high-amplitude swelling of mitochondria, yet it requires higher concentrations of Ca(2+) (30 and 100μM for PA and OA respectively). (5) In contrast to PA, OA is unable to cause the Ca(2+)-dependent high-amplitude swelling of mitoplasts, suggesting that the cause of OA/Ca(2+)-induced permeability transition in mitochondria may be the fusion of the inner and outer mitochondrial membranes. (6) The presence of OA enhances PA/Ca(2+)-induced permeabilization of liposomes and mitochondria. The paper discusses possible mechanisms of PA/Ca(2+)- and OA/Ca(2+)-induced membrane permeabilization, the probability of these mechanisms to be realized in the cell, and their possible physiological role.
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, 142290 Pushchino, Moscow Region, 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, 142290 Pushchino, Moscow Region, Russia; Pushchino State Institute of Natural Sciences, 142290 Pushchino, Moscow Region, Russia.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Belosludtseva
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, 142290 Pushchino, Moscow Region, Russia; Pushchino State Institute of Natural Sciences, 142290 Pushchino, Moscow Region, Russia.
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Agafonov
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, 142290 Pushchino, Moscow Region, Russia; Institute of Cell biophysics RAS, Institutskaya 3, Pushchino, Moscow region 142290, Russia.
authors.forename: Maxim E
authors.initials: ME
authors.lastname: Astashev
authors.affiliation: Institute for biological instrumentation RAS, Institutskaya 7, Pushchino, Moscow region 142290, Russia.
authors.forename: Alexey S
authors.initials: AS
authors.lastname: Kazakov
authors.affiliation: University of Helsinki, Helsinki, POB 56 Biocenter 1, FIN-00014, Finland.
authors.forename: Nils-Erik L
authors.initials: NE
authors.lastname: Saris
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, 142290 Pushchino, Moscow Region, Russia; Pushchino State Institute of Natural Sciences, 142290 Pushchino, Moscow Region, Russia.
authors.forename: Galina D
authors.initials: GD
authors.lastname: Mironova
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008930:Mitochondria, Liver / Q000737:chemistry / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000737:chemistry / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000737:chemistry / Q000378:metabolism*; D000083162:Mitochondrial Permeability Transition Pore; D019301:Oleic Acid / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D019308:Palmitic Acid / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010539:Permeability; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004791:Enzyme Inhibitors; D008081:Liposomes; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D019301:Oleic Acid; D019308:Palmitic Acid; D002118:Calcium
keywords: Calcium; Liposomes; Membrane permeabilization; Mitochondria; Oleic acid; Palmitic acid