Bilayer elasticity at the nanoscale: the need for new terms

Abstract

Continuum elastic models that account for membrane thickness variations are especially useful in the description of nanoscale deformations due to the presence of membrane proteins with hydrophobic mismatch. We show that terms involving the gradient and the Laplacian of the area per lipid are significant and must be retained in the effective Hamiltonian of the membrane. We reanalyze recent numerical data, as well as experimental data on gramicidin channels, in light of our model. This analysis yields consistent results for the term stemming from the gradient of the area per molecule. The order of magnitude we find for the associated amplitude, namely 13-60 mN/m, is in good agreement with the 25 mN/m contribution of the interfacial tension between water and the hydrophobic part of the membrane. The presence of this term explains a systematic variation in previously published numerical data.

34 pages, 9 figures

References in corpus (3)

• Membrane-Protein Interactions in a Generic Coarse-Grained Model for Lipid Bilayers
• Microscopic membrane elasticity and interactions among membrane inclusions: Interplay between the shape, dilation, tilt and tilt-difference modes
• Membrane stress tensor in the presence of lipid density and composition inhomogeneities

Cited by in corpus (8)

• Bilayer-thickness-mediated interactions between integral membrane proteins
• Additional contributions to elastic energy of lipid membranes: Tilt-curvature coupling and curvature gradient
• Field-Embedded Particles Driven by Active Flips
• Hydrodynamics of bilayer membranes with diffusing transmembrane proteins
• Spatial Organization of Active Particles with Field Mediated Interactions
• Coupling between Inclusions and Membranes at the Nanoscale
• Membrane-mediated interactions
• Controlling the shape of membrane protein polyhedra