Elasticity of bilayer lipid membranes from their density correlation function

We study the density correlation function (DCF) of DPPC lipid bilayers. We compare Molecular Dynamics (MD) results with theoretical predictions obtained with a mesoscopic description, in terms of the lipid membrane elasticity. One key objective of our work is the quantification of the lipid membrane...

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Detalles Bibliográficos
Autores: Chacón, Enrique, Bresme, F., Tarazona, P.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/392590
Acceso en línea:http://hdl.handle.net/10261/392590
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85193051233&doi=10.1080%2f00268976.2024.2346262&partnerID=40&md5=5ea0f585c8a19e6139fcd75fdd0a4c60
Access Level:acceso abierto
Palabra clave:Bilayer lipid membranes
capillary waves
molecular dynamics
structure factor
X-ray surface diffraction
Descripción
Sumario:We study the density correlation function (DCF) of DPPC lipid bilayers. We compare Molecular Dynamics (MD) results with theoretical predictions obtained with a mesoscopic description, in terms of the lipid membrane elasticity. One key objective of our work is the quantification of the lipid membrane elasticity directly from the DCF, both for the membrane undulations and local membrane thickness. Our method does not require the definition of instantaneous surfaces or internal variables defining lipid orientations. Building on our previous work, here we focus on the intralayer correlations, i.e. the DCF of lipids residing on the same monolayer, by tracking only the position of the phosphorus atoms in a lipid head group. We demonstrate the relevance of the intralayer two-dimensional (2D) correlations to the total DCF. We further show that all-atom (AA) and coarse grained (CG) lipid forcefields, feature distintively different DCFs. The CG forcefield predicts results in good agreement with the mesoscopic predictions, for the entire wavevector range; the AA forcefield (CHARMM36) predict strong peristaltic fluctuations at long wavevectors (Formula presented.) nm (Formula presented.), which are absent in the CG lipid model (MARTINI). © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.