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Nanoscale Bending Dynamics in Mixed-Chain Lipid Membranes
Published
Author(s)
Elizabeth Kelley, Moritz Frewein, Orsolya Czakkel, Michihiro Nagao
Abstract
Lipids that have two tails of different lengths are found throughout biomembranes in nature, yet the effects of this asymmetry on the membrane properties, are not well understood, especially when it comes to the membrane dynamics. Here we study the nanoscale bending fluctuations in model mixed-chain 14:0-18:0 PC (MSPC) and 18:0-14:0 PC (SMPC) lipid bilayers using neutron spin echo (NSE) spectroscopy. We find that despite the partial interdigitation that is known to persist in the fluid phase of these membranes, the collective fluctuations are enhanced on timescales of tens of nanoseconds, and the asymmetric lipid bilayers are softer than an analogous symmetric lipid with the same average number of carbons in the acyl tails, di-16:0 PC (DPPC). Quantitative comparison of the NSE results suggests that the enhanced bending fluctuations at the nanosecond timescales are consistent with experimental and computational studies that showed the compressibility moduli of chain-asymmetric lipid membranes are 20 % to 40 % lower than chain-symmetric lipid membranes. These studies add to growing evidence that the partial interdigitation in mixed-chain lipid membranes is highly dynamic in the fluid phase and impacts membrane dynamic processes from the molecular to mesoscopic length scales without significantly changing the bilayer thickness or area per lipid.
Kelley, E.
, Frewein, M.
, Czakkel, O.
and Nagao, M.
(2023),
Nanoscale Bending Dynamics in Mixed-Chain Lipid Membranes, Symmetry, [online], https://dx.doi.org/10.3390/sym15010191
(Accessed April 27, 2024)