Lateral pressure profile in bent lipid membranes and mechanosensitive channel gating

Abstract

This review describes the analytical calculation of lateral pressure profile in the hydrophobic part of the lipid bilayer with finite curvature based on previously developed microscopic model for lipid hydrocarbon chains. According to this theory the energy per unit chain is represented as energy of flexible string (Eulers elastic beam of finite thickness) and interaction between chains is considered as an entropic repulsion. This microscopic theory allows to obtain expression for lateral pressure distribution in bent bilayer if treating a bending as a small deviation from the flat membrane conformation and using perturbation theory. Because lateral pressure distribution is related to elastic properties of lipid bilayer then the first moment of lateral pressure and the expression for bending modulus may be derived from this theoretical model. Finally one can estimate the energy difference between two various conformational states of mechanosensitive channel embedded into the bilayer with pressure profile [Pcy]t(z).