Electroelastic coupling between membrane surface fluctuations and membrane-embedded charges: Continuum multidielectric treatment

摘要: The coupling of electric fields and charges with membrane-water interfacial fluctuations affects membrane electroporation, ionic conductance, voltage gating. A modified continuum model is introduced to study charge interaction in multidielectric environments. By surrounding a point low dielectric sphere, the linear Poisson–Boltzmann equation directly solved by calculating reaction field potential via method that eliminates singularity contributions. This allows treatment located at boundaries. Two complementary mechanisms governing charge-fluctuation interactions are considered: (1) electroelastic deformation (EED), treating as an elastic slab (smectic bilayer model), (2) electrohydrophobic solvation (EHS), accounting for water penetration into membrane’s hydrophobic core. EED often leads large thickness perturbations, far larger than those consistent descriptions [M. B. Partenskii, G. V. Miloshevsky, P. C. Jordan, Isr. J. Chem. 47, 385 (2007)]. We argue switch from EHS can be energetically advantageous intermediate perturbation amplitudes. Both simulated introducing adjustable shapes optimized kinetic Monte Carlo path following approach [G. Miloshevsky Phys. 122, 214901 (2005)]. resulting energy profiles agree recent atomistic molecular dynamics studies on translating charged residue across lipid [S. Dorairaj T. W. Allen, Proc. Natl. Acad. Sci. U.S.A. 104, 4943