title: Collective dynamics in fully hydrated phospholipid bilayers studied by inelastic x-ray scattering.
abstract: The short wavelength density fluctuation of DLPC (dilaurylphosphatidylcholine) bilayers close to full hydration has been studied by the inelastic x-ray scattering technique below and above the main transition temperature. The analysis based on a generalized three effective eigenmode theory allows us to construct the dispersion relation of the high frequency sound mode for the first time. The marked softening of the excitation near k = 14 nm(-1), corresponding to the lipid chain-chain correlation peak in the structure factor, in the L(alpha) phase implies prevalent occurrences of short-wavelength in-plane motions of lipid chains that might be of importance for transportation of small molecules across membranes.
authors.affiliation: Department of Nuclear Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Chen
authors.forename: C Y
authors.initials: CY
authors.lastname: Liao
authors.forename: H W
authors.initials: HW
authors.lastname: Huang
authors.forename: T M
authors.initials: TM
authors.lastname: Weiss
authors.forename: M C
authors.initials: MC
authors.lastname: Bellisent-Funel
authors.forename: F
authors.initials: F
authors.lastname: Sette
mesh_terms: D008051:Lipid Bilayers; D010713:Phosphatidylcholines / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D012542:Scattering, Radiation; D014965:X-Rays
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010743:Phospholipids; C015153:1,2-dilauroylphosphatidylcholine