Electrostatic interaction effects on tension-induced pore formation in lipid membranes.
We investigated the effects of electrostatic interactions on the rate constant (k(p)) for tension-induced pore formation in lipid membranes of giant unilamellar vesicles under constant applied tension. A decrease in salt concentration in solution as well as an increase in surface charge density of the membranes increased k(p). These data indicate that k(p) increases as the extent of electrostatic interaction increases. We developed a theory on the effect of the electrostatic interactions on the free energy profile of the membrane containing a prepore and also on the values of k(p); this theory explains the experimental results and fits the experimental data reasonably well in the presence of weak electrostatic interactions. Based on these results, we conclude that a decrease in the free energy barrier of the prepore state due to electrostatic interactions is the main factor causing an increase in k(p).
Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan.
Mohammad Abu Sayem
MA
Karal
Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan.|Theoretical Problem Center of Physico-Chemical Pharmacology, Russian Academy of Sciences, Kоsugina, 4, Moscow 117977, Russia.|Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka 422-8529, Japan.
Victor
V
Levadnyy
Department of Physics, Graduate School of Science, Shizuoka University, Shizuoka 422-8529, Japan.
Taka-aki
TA
Tsuboi
Theoretical Problem Center of Physico-Chemical Pharmacology, Russian Academy of Sciences, Kоsugina, 4, Moscow 117977, Russia.
Marina
M
Belaya
Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan.|Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka 422-8529, Japan.|Department of Physics, Graduate School of Science, Shizuoka University, Shizuoka 422-8529, Japan.
Masahito
M
Yamazaki
D008954:Models, Biological; D010713:Phosphatidylcholines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D016062:Porosity; D012492:Salts / Q000737:chemistry; D055672:Static Electricity; D013500:Surface Tension; D053835:Unilamellar Liposomes / Q000737:chemistry
D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D012492:Salts; D053835:Unilamellar Liposomes; C051388:1,2-dioleoyl-sn-glycero-3-phosphoglycerol; C017251:1,2-oleoylphosphatidylcholine