Lipid-protein interactions and heterogeneous lipid distribution in membranes.

The specificity of lipid interactions with both integral and peripheral proteins is discussed in terms of the microscopic heterogeneity in lipid distribution to which they give rise. The factors giving rise to macroscopic phase separation, namely hydrophobic mismatch for integral proteins and phase transitions for lipid bilayers, also are considered. Simple thermodynamic or phenomenological models are given for the way in which specific lipid interactions with peripheral or integral proteins may be coupled to intrinsic lipid phase transitions and thus enhance the phase separation or domain formation of the lipid.