Biomaterial Database

Phase transitions in coarse-grained lipid bilayers containing cholesterol by molecular dynamics simulations. 2012

Qaiser Waheed, and Richard Tjörnhammar, and Olle Edholm

Theoretical Biological Physics, Department of Theoretical Physics, Royal Institute of Technology (KTH), AlbaNova University Center, Stockholm, Sweden.

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.

UI	MeSH Term	Description	Entries
D008051	Lipid Bilayers	Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.	Bilayers, Lipid,Bilayer, Lipid,Lipid Bilayer
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D003460	Crystallization	The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Crystalline Polymorphs,Polymorphism, Crystallization,Crystal Growth,Polymorphic Crystals,Crystal, Polymorphic,Crystalline Polymorph,Crystallization Polymorphism,Crystallization Polymorphisms,Crystals, Polymorphic,Growth, Crystal,Polymorph, Crystalline,Polymorphic Crystal,Polymorphisms, Crystallization,Polymorphs, Crystalline
D005782	Gels	Colloids with a solid continuous phase and liquid as the dispersed phase; gels may be unstable when, due to temperature or other cause, the solid phase liquefies; the resulting colloid is called a sol.
D044366	Transition Temperature	The temperature at which a substance changes from one state or conformation of matter to another.	Temperature, Transition,Boiling Point Temperature,Freezing Point Temperature,Melting Point Temperature,Boiling Point Temperatures,Freezing Point Temperatures,Melting Point Temperatures,Temperature, Boiling Point,Temperature, Freezing Point,Temperature, Melting Point,Temperatures, Boiling Point,Temperatures, Freezing Point,Temperatures, Melting Point,Temperatures, Transition,Transition Temperatures
D044367	Phase Transition	A change of a substance from one form or state to another.	Gas-Liquid-Solid Phase Transitions,Sol-Gel Phase Transition,Gas Liquid Solid Phase Transitions,Gas-Liquid-Solid Phase Transition,Phase Transition, Gas-Liquid-Solid,Phase Transition, Sol-Gel,Phase Transitions,Phase Transitions, Gas-Liquid-Solid,Phase Transitions, Sol-Gel,Sol Gel Phase Transition,Sol-Gel Phase Transitions,Transition, Gas-Liquid-Solid Phase,Transition, Sol-Gel Phase,Transitions, Gas-Liquid-Solid Phase,Transitions, Sol-Gel Phase
D056004	Molecular Dynamics Simulation	A computer simulation developed to study the motion of molecules over a period of time.	Molecular Dynamics Simulations,Molecular Dynamics,Dynamic, Molecular,Dynamics Simulation, Molecular,Dynamics Simulations, Molecular,Dynamics, Molecular,Molecular Dynamic,Simulation, Molecular Dynamics,Simulations, Molecular Dynamics