Nucleation of symmetric domains in the coupled leaflets of a bilayer

Abstract

We study the kinetics governing the attainment of inter-leaflet domain symmetry in a phase-separating amphiphilic bilayer. "Indirect" inter-leaflet coupling via hydrophobic mismatch can induce an instability towards a metastable pattern of locally asymmetric domains upon quenching from high temperature. This necessitates a nucleation step to form the conventional symmetric pattern of domains, which are favoured by a "direct" inter-leaflet coupling. We model the energetics for a symmetric domain to nucleate from the metastable state, and find that an interplay between hydrophobic mismatch and thickness stretching/compression causes the effective hydrophobic mismatch, and thus line tension, to depend on domain size. This leads to strong departure from classical nucleation theory. We speculate on implications for cell membrane rafts or clusters, whose size may be of similar magnitude to estimated critical radii for domain symmetry.

Final accepted version, published in Soft Matter 2015 (DOI: 10.1039/C5SM01328C)

References in corpus (2)

• Monolayer curvature stabilizes nanoscale raft domains in mixed lipid bilayers
• Bilayer registry in a multicomponent asymmetric membrane : dependence on lipid composition and chain length

Cited by in corpus (4)

• Physical mechanisms of micro- and nanodomain formation in multicomponent lipid membranes
• Kinetics of symmetry and asymmetry in a phase-separating bilayer membrane
• Comment on "Elastic Membrane Deformations Govern Interleaflet Coupling of Lipid-Ordered Domains"
• Effects of passive phospholipid flip-flop and asymmetric external fields on bilayer phase equilibria