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Hydrodynamics of bilayer membranes with diffusing transmembrane proteins

Authors :
Marc Durand
Andrew Callan-Jones
Jean-Baptiste Fournier
Matière et Systèmes Complexes (MSC (UMR_7057))
Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Source :
Soft Matter, Soft Matter, Royal Society of Chemistry, 2016, 12, ⟨10.1039/c5sm02507a⟩
Publication Year :
2016
Publisher :
Royal Society of Chemistry (RSC), 2016.

Abstract

International audience; We consider the hydrodynamics of lipid bilayers containing transmembrane proteins of arbitrary shape. This biologically-motivated problem is relevant to the cell membrane, whose fluctuating dynamics play a key role in phenomena ranging from cell migration, intercellular transport, and cell communication. Using Onsager's variational principle, we derive the equations that govern the relaxation dynamics of the membrane shape, of the mass densities of the bilayer leaflets, and of the diffusing proteins' concentration. With our generic formalism, we obtain several results on membrane dynamics. We find that proteins that span the bilayer increase the intermonolayer friction coefficient. The renormalization, which can be significant, is in inverse proportion to the protein's mobility. Second, we find that asymmetric proteins couple to the membrane curvature and to the difference in monolayer densities. For practically all accessible membrane tensions (σ > 10 −8 N/m) we show that the protein density is the slowest relaxing variable. Furthermore, its relaxation rate decreases at small wavelengths due to the coupling to curvature. We apply our formalism to the large-scale diffusion of a concentrated protein patch. We find that the diffusion profile is not self-similar, owing to the wavevector dependence of the effective diffusion coefficient.

Details

ISSN :
17446848 and 1744683X
Volume :
12
Database :
OpenAIRE
Journal :
Soft Matter
Accession number :
edsair.doi.dedup.....1b1782c238644e529cc2edbd598adb99
Full Text :
https://doi.org/10.1039/c5sm02507a