Dielectric properties of the polar head group region of zwitterionic lipid bilayers.

摘要: A theoretical model describing the dielectric properties of lipid membrane-water interface region was developed. The rotating polar head groups (e.g. phosphatidylcholine) were simulated as a collection interacting dipoles imbedded in nonhomogeneous dielectric. interactions between nearest neighborhood explicitly taken into account, while other evaluated by means continuum theories. values constant, its anisotropy and spontaneous polarization evaluated. As an application, we calculated energy interaction ion membrane group region. results indicate small (1–1.7 Debyes per molecule) due to tilting angle choline residue with respect surface. This dipolar field partially compensates that opposite orientation originating from ester region, giving overall potentials better agreement experimental data. Our suggests also very strong component constant perpendicular plane being much smaller than parallel component.