Abstract
Currently, there is no comprehensive model for the dynamics of cellular membranes.
The understanding of even the basic dynamic processes, such as lateral
diffusion of lipids, is still quite limited. Recent studies of
one-component membrane systems have shown
that instead of single-particle motions, the lateral diffusion is
driven by a more complex, concerted mechanism for lipid diffusion (E. Falck et al., J. Am. Chem. Soc., 2008, 130, 44–45), where a lipid and its neighbors move in unison in terms of loosely defined clusters. In this work, we extend the previous study by considering the concerted lipid diffusion phenomena in many-component raft-like membranes.
This nature of diffusion phenomena emerge in all the cases we have
considered, including both atom-scale simulations of lateral diffusion
within rafts and coarse-grained MARTINI simulations of diffusion in membranes
characterized by coexistence of raft and non-raft domains. The data
allows us to identify characteristic time scales for the concerted lipid
motions, which turn out to range from hundreds of nanoseconds to
several microseconds. Further, we characterize typical length scales
associated with the correlated lipid
diffusion patterns and find them to be about 10 nm, or even larger if
weak correlations are taken into account. Finally, the concerted nature
of lipid motions is also found in dissipative particle dynamics simulations of lipid membranes, clarifying the role of hydrodynamics (local momentum conservation) in membrane diffusion phenomena.
Original language | English |
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Pages (from-to) | 411-430 |
Journal | Faraday Discussions |
Volume | 144 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2010 |
MoE publication type | A1 Journal article-refereed |