title: Molecular dynamics simulations and NMR spectroscopy studies of trehalose-lipid bilayer systems.
abstract: The disaccharide trehalose (TRH) strongly affects the physical properties of lipid bilayers. We investigate interactions between lipid membranes formed by 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and TRH using NMR spectroscopy and molecular dynamics (MD) computer simulations. We compare dipolar couplings derived from DMPC/TRH trajectories with those determined (i) experimentally in TRH using conventional high-resolution NMR in a weakly ordered solvent (bicelles), and (ii) by solid-state NMR in multilamellar vesicles (MLV) formed by DMPC. Analysis of the experimental and MD-derived couplings in DMPC indicated that the force field used in the simulations reasonably well describes the experimental results with the exception for the glycerol fragment that exhibits significant deviations. The signs of dipolar couplings, not available from the experiments on highly ordered systems, were determined from the trajectory analysis. The crucial step in the analysis of residual dipolar couplings (RDCs) in TRH determined in a bicelle-environment was access to the conformational distributions derived from the MD trajectory. Furthermore, the conformational behavior of TRH, investigated by J-couplings, in the ordered and isotropic phases is essentially identical, indicating that the general assumptions in the analyses of RDCs are well founded.
authors.affiliation: Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden. arnold.maliniak@mmk.su.se.
authors.forename: Jon
authors.initials: J
authors.lastname: Kapla
authors.forename: Olof
authors.initials: O
authors.lastname: Engström
authors.forename: Baltzar
authors.initials: B
authors.lastname: Stevensson
authors.forename: Jakob
authors.initials: J
authors.lastname: Wohlert
authors.forename: Göran
authors.initials: G
authors.lastname: Widmalm
authors.forename: Arnold
authors.initials: A
authors.lastname: Maliniak
mesh_terms: D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D006860:Hydrogen Bonding; D008051:Lipid Bilayers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D012997:Solvents / Q000737:chemistry; D014199:Trehalose / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D012997:Solvents; D014199:Trehalose; D004134:Dimyristoylphosphatidylcholine