title: Phase transitions in coarse-grained lipid bilayers containing cholesterol by molecular dynamics simulations.
abstract: Coarse-grained simulations of model membranes containing mixtures of phospholipid and cholesterol molecules at different concentrations and temperatures have been performed. A random mixing without tendencies for segregation or formation of domains was observed on spatial scales corresponding to a few thousand lipids and timescales up to several microseconds. The gel-to-liquid crystalline phase transition is successively weakened with increasing amounts of cholesterol without disappearing completely even at a concentration of cholesterol as high as 60%. The phase transition temperature increases slightly depending on the cholesterol concentration. The gel phase system undergoes a transition with increasing amounts of cholesterol from a solid-ordered phase into a liquid-ordered one. In the solid phase, the amplitude of the oscillations in the radial distribution function decays algebraically with a prefactor that goes to zero at the solid-liquid transition.
authors.affiliation: Theoretical Biological Physics, Department of Theoretical Physics, Royal Institute of Technology (KTH), AlbaNova University Center, Stockholm, Sweden.
authors.forename: Qaiser
authors.initials: Q
authors.lastname: Waheed
authors.forename: Richard
authors.initials: R
authors.lastname: Tjörnhammar
authors.forename: Olle
authors.initials: O
authors.lastname: Edholm
mesh_terms: D002784:Cholesterol / Q000737:chemistry*; D003460:Crystallization; D005782:Gels / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D044367:Phase Transition; D010743:Phospholipids / Q000737:chemistry; D044366:Transition Temperature
chemical_list: D005782:Gels; D008051:Lipid Bilayers; D010743:Phospholipids; D002784:Cholesterol