An outlook on organization of lipids in membranes: searching for a realistic connection with the organization of biological membranes.
Lipid-bilayer membranes are formed by self-assembly processes. The molecular interactions within the bilayer and with the environment impart a unique trans-bilayer lateral pressure profile and provide a set of physical mechanisms for formation of lipid domains and laterally differentiated regions in the plane of the membrane. Results from a number of experimental and theoretical studies of model lipid bilayers are reviewed, emphasizing the significance of these fundamental physical properties for the structure and dynamics of biological membranes. Particular attention is paid to the relevance of postulating the existence of equilibrium thermodynamic phases in biological membranes. This includes a discussion of the possible significance of equilibrium critical points in biological membrane systems that normally exist under non-equilibrium conditions. The need for a new model to replace the celebrated Nicolson-Singer fluid-mosaic model of biological membranes is also discussed.
Bagatolli
Luis A
LA
MEMPHYS-Center for Biomembrane Physics, Membrane Biophysics and Biophotonics Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, Odense M, Denmark. bagatolli@memphys.sdu.dk
Ipsen
John H
JH
Simonsen
Adam C
AC
Mouritsen
Ole G
OG
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry* / Q000648:ultrastructure; D005456:Fluorescent Dyes / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry; D008954:Models, Biological; D013816:Thermodynamics
D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008563:Membrane Lipids; D008565:Membrane Proteins