title: Molecular dynamics simulation of n-dodecyl phosphate aggregate structures.
abstract: Aggregates of n-dodecyl phosphate present an attractive model system of simple phospholipid amphiphile supramolecular structures for study by molecular dynamics simulation, since these systems have previously been studied experimentally under various conditions. A detailed molecular dynamics description of the properties of planar bilayer membranes (as a model for unilamellar vesicular membranes) and spherical micelles under various simulated conditions is presented. It is shown that the united-atom model of GROMOS96 applying the force-field parameter set 43A2 for biomolecular systems yields properties in agreement with experimental ones in most cases. Hydrogen bonding plays a role in stabilizing the bilayer aggregates at low pH, but not for the micelles, which are energetically favoured at high pH. NMR -S(CD) order parameters for a lipid bilayer system, the diffusion of amphiphiles within aggregates and of counterions, and lifetimes of hydrogen bonds between amphiphiles and to water are estimated from the MD simulations.
authors.affiliation: Department of Chemistry, Swiss Federal Institute of Technology Zürich, ETH-Zentrum, Switzerland.
authors.forename: L D
authors.initials: LD
authors.lastname: Schuler
authors.forename: P
authors.initials: P
authors.lastname: Walde
authors.forename: P L
authors.initials: PL
authors.lastname: Luisi
authors.forename: W F
authors.initials: WF
authors.lastname: van Gunsteren
mesh_terms: D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D010755:Organophosphates / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D008823:Micelles; D010755:Organophosphates; D014867:Water; C052807:didodecyl phosphate