Enhance Dynamics in the Anomalous Melting Regime of DMPG Lipid Membranes

Published

October 16, 2020

Author(s)

Elizabeth Kelley, Michihiro Nagao, Paul Butler, Lionel Porcar, Bela Farago

Abstract

Like many soft materials, lipids undergo a melting transition associated with a significant increase in their dynamics. At temperatures below the main melting transition (T_m), all molecular and collective dynamics are suppressed, while above T_m the alkyl tail motions, diffusivity, and collective membrane undulations are at least an order of magnitude faster. Here we study the collective dynamics of dimyristoylphosphatidylglycerol (14:0 PG, DMPG) using neutron spin echo spectroscopy (NSE) throughout its anomalous phase transition that occurs over a 12 °C to 20 °C wide temperature window. Our results reveal that the membranes are softer and more dynamic during the phase transition than at higher temperatures corresponding to the fluid phase and provide direct experimental evidence for the predicted increase in membrane fluctuations during lipid melting. These results provide new insights into the nanoscale lipid membrane dynamics during the melting transition and demonstrate how these dynamics are coupled to changes in the membrane structure.

Citation

Structural Dynamics

Volume

7

Issue

5

Pub Type

Journals

Keywords

phase transition, lipid melting, neutron scattering, dynamics

Citation

Kelley, E. , Nagao, M. , Butler, P. , Porcar, L. and Farago, B. (2020), Enhance Dynamics in the Anomalous Melting Regime of DMPG Lipid Membranes, Structural Dynamics (Accessed December 13, 2024)