Phonons reveal coupled cholesterol-lipid dynamics in ternary membranes.

ABSTRACT: Experimental studies of collective dynamics in lipid bilayers have been challenging due to the energy resolution required to observe these low-energy phonon-like modes. However, inelastic x-ray scattering (IXS) measurements-a technique for probing vibrations in soft and biological materials-are now possible with sub-meV resolution, permitting direct observation of low-energy, phonon-like modes in lipid membranes. Here, IXS measurements with sub-meV energy resolution reveal a low-energy optic-like phonon mode at roughly 3 meV in the liquid-ordered (L_o) and liquid-disordered phases of a ternary lipid mixture. This mode is only observed experimentally at momentum transfers greater than 5 nm^-1 in the L_o system. A similar gapped mode is also observed in all-atom

SUBMITTER: Fitzgerald JE 

PROVIDER: S-EPMC11628849 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature