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Title: Revealing the mechanism of passive transport in lipid bilayers via phonon-mediated nanometre-scale density fluctuations

We report the high resolution inelastic x-ray study of the in-plane phonon excitations in dipalmitoyl phosphatidylcholine (DPPC) above and below main transition temperature. In the L β' gel phase, we observe high frequency longitudinal phonon mode previously predicted by the molecular dynamics simulations and for the first time, we reveal low frequency weakly dispersive transverse acoustic mode which softens and exhibits a low-frequency phonon gap when the DPPC lipid transitions into the L α fluid phase. The phonon softening of the high frequency longitudinal excitations and the transformation of the transverse excitations upon the phase transition from the L β' to L α phase is explained within the framework of the phonon theory of liquids. These findings illustrate the importance of the collective dynamics of biomembranes and reveal that hydrocarbon tails can act as an efficient mediator in controlling the passive transport across the bilayer plane.
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [5] ;  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation)
  3. Inst. of Nanoscience and Cryogenics, Grenoble (France)
  4. Petersburg Nuclear Physics Inst. Gatchina (Russia)
  5. European Synchrotron Radiation Facility (ESRF), Grenoble (France)
Publication Date:
Report Number(s):
BNL-108276-2015-JA; BNL-112571-2016-JA
Journal ID: ISSN 2041-1723; R&D Project: LS001
Grant/Contract Number:
SC0012704
Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Russian Foundation for Basic Research
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Membrane biophysics; Membrane lipids; 59 BASIC BIOLOGICAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1237168
Alternate Identifier(s):
OSTI ID: 1340385