title: Constant normal pressure, constant surface tension, and constant temperature molecular dynamics simulation of hydrated 1,2-dilignoceroylphosphatidylcholine monolayer.
abstract: A constant normal pressure, constant surface tension, and constant temperature (NP(N)gammaT) molecular dynamics (MD) simulation of the liquid condensed phase of a 1,2-dilignoceroylphosphatidylcholine (DLGPC) monolayer has been performed at 293.15 K. A DLGPC molecule has two saturated 24-carbon acyl chains, giving the hydrocarbon core thickness of the monolayer approximately 28 A, which is close to the hydrocarbon core thickness of a membrane of a living system. NP(N)gammaT ensemble was used to reproduce the experimental observations, such as area/lipid, because surface tension is an essential factor in determining the monolayer structure. Data analysis on DLGPC/water monolayer shows that various liquid condensed-phase properties of the monolayer have been well reproduced from the simulation, indicating that surface tension 22.9 mN/M used in the simulation is an appropriate condition for the condensed-phase NP(N)gammaT simulation. The simulation results suggest that this long-chain phospholipid monolayer shares many structural characteristics with typical short-chain 1,2-diacylphosphatidylcholine systems, such as DPPC/water monolayer in the condensed phase and DPPC/water bilayer in the gel phase. Furthermore, it was found that DLGPC/water monolayer has almost completely rotationally disordered acyl chains, which have not been observed so far in short-chain 1,2-diacylphosphatidylcholine/water bilayers. This study indicates the good biological relevance of the DLGPC/water monolayer which might be useful in protein/lipid studies to reveal protein structure and protein/lipid interactions in a membrane environment.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. sunf@sas.upenn.edu
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
mesh_terms: D000215:Acylation; D003198:Computer Simulation; D008958:Models, Molecular; D008962:Models, Theoretical; D008968:Molecular Conformation; D010713:Phosphatidylcholines / Q000737:chemistry*; D011312:Pressure; D013500:Surface Tension; D013816:Thermodynamics; D014867:Water
chemical_list: C465422:1,2-dilignoceroylphosphatidylcholine; D010713:Phosphatidylcholines; D014867:Water