Effects of charge fluctuation on two-membrane instability and fusion.
Membrane fusion is fundamental to diverse biological processes ranging from intercellular and intracellular transport to egg fertilization. We study the effects of coupling between membrane undulation and charge fluctuation on its fusion. We find that, at concentrations of millimolar range, multivalent cations such as calcium in solution induce a strong correlated-charge fluctuation on each membrane, leading to inversion and overcondensation of surface charges. When the charge fluctuation is cooperatively coupled to undulation, two apposing membranes undergo a dynamic instability to spontaneous growth of in-phase undulation with submicron wavelengths, thereby greatly reducing fusion barrier.
Kim
Yong Woon
YW
Department of Physics, Pohang University of Science and Technology, Pohang 790-784, South Korea.
Sung
Wokyung
W
D002118:Calcium / Q000737:chemistry; D002413:Cations, Divalent / Q000737:chemistry; D008561:Membrane Fusion / Q000502:physiology*; D008566:Membranes / Q000737:chemistry / Q000502:physiology; D008954:Models, Biological
D002413:Cations, Divalent; D002118:Calcium