Liquid-liquid immiscibility in membranes.
The observation of liquid-liquid immiscibility in cholesterol-phospholipid mixtures in monolayers and bilayers has opened a broad field of research into their physical chemistry. Some mixtures exhibit multiple immiscibilities. This unusual property has led to a thermodynamic model of "condensed complexes." These complexes are the consequence of an exothermic, reversible reaction between cholesterol and phospholipids. In this quantitative model the complexes are sometimes concentrated in a separate liquid phase. The phase separation into a complex-rich phase depends on membrane composition and intensive variables such as temperature. The properties of defined cholesterol-phospholipid mixtures provide a conceptual foundation for the exploration of a number of aspects of the biophysics and biochemistry of animal cell membranes.
McConnell
Harden M
HM
Department of Chemistry, Biophysics Program, Stanford University, Stanford, California 94305-5080, USA. harden@stanford.edu
Vrljic
Marija
M
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D046911:Macromolecular Substances; D008560:Membrane Fluidity; D021962:Membrane Microdomains / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry; D008567:Membranes, Artificial; D010743:Phospholipids / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry*
D003102:Colloids; D008051:Lipid Bilayers; D046911:Macromolecular Substances; D008565:Membrane Proteins; D008567:Membranes, Artificial; D010743:Phospholipids; D012996:Solutions; D002784:Cholesterol