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Title: A computer simulation approach to quantify the true area and true area compressibility modulus of biological membranes

Abstract

We present a new computational approach to quantify the area per lipid and the area compressibility modulus of biological membranes. Our method relies on the analysis of the membrane fluctuations using our recently introduced coupled undulatory (CU) mode [Tarazona et al., J. Chem. Phys. 139, 094902 (2013)], which provides excellent estimates of the bending modulus of model membranes. Unlike the projected area, widely used in computer simulations of membranes, the CU area is thermodynamically consistent. This new area definition makes it possible to accurately estimate the area of the undulating bilayer, and the area per lipid, by excluding any contributions related to the phospholipid protrusions. We find that the area per phospholipid and the area compressibility modulus features a negligible dependence with system size, making possible their computation using truly small bilayers, involving a few hundred lipids. The area compressibility modulus obtained from the analysis of the CU area fluctuations is fully consistent with the Hooke’s law route. Unlike existing methods, our approach relies on a single simulation, and no a priori knowledge of the bending modulus is required. We illustrate our method by analyzing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayers using the coarse grained MARTINI force-field. The area per lipid and area compressibilitymore » modulus obtained with our method and the MARTINI forcefield are consistent with previous studies of these bilayers.« less

Authors:
 [1];  [2];  [3]
  1. Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid, Spain and Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid 28049 (Spain)
  2. Departamento de Física Teórica de la Materia Condensada, Condensed Matter Physics Center (IFIMAC), and Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid 28049 (Spain)
  3. Department of Chemistry, Imperial College London, SW7 2AZ London (United Kingdom)
Publication Date:
OSTI Identifier:
22489731
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 143; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BENDING; CALCULATION METHODS; COMPRESSIBILITY; COMPUTERIZED SIMULATION; LAYERS; MEMBRANES; PHOSPHOLIPIDS

Citation Formats

Chacón, Enrique, Tarazona, Pedro, and Bresme, Fernando. A computer simulation approach to quantify the true area and true area compressibility modulus of biological membranes. United States: N. p., 2015. Web. doi:10.1063/1.4926938.
Chacón, Enrique, Tarazona, Pedro, & Bresme, Fernando. A computer simulation approach to quantify the true area and true area compressibility modulus of biological membranes. United States. https://doi.org/10.1063/1.4926938
Chacón, Enrique, Tarazona, Pedro, and Bresme, Fernando. 2015. "A computer simulation approach to quantify the true area and true area compressibility modulus of biological membranes". United States. https://doi.org/10.1063/1.4926938.
@article{osti_22489731,
title = {A computer simulation approach to quantify the true area and true area compressibility modulus of biological membranes},
author = {Chacón, Enrique and Tarazona, Pedro and Bresme, Fernando},
abstractNote = {We present a new computational approach to quantify the area per lipid and the area compressibility modulus of biological membranes. Our method relies on the analysis of the membrane fluctuations using our recently introduced coupled undulatory (CU) mode [Tarazona et al., J. Chem. Phys. 139, 094902 (2013)], which provides excellent estimates of the bending modulus of model membranes. Unlike the projected area, widely used in computer simulations of membranes, the CU area is thermodynamically consistent. This new area definition makes it possible to accurately estimate the area of the undulating bilayer, and the area per lipid, by excluding any contributions related to the phospholipid protrusions. We find that the area per phospholipid and the area compressibility modulus features a negligible dependence with system size, making possible their computation using truly small bilayers, involving a few hundred lipids. The area compressibility modulus obtained from the analysis of the CU area fluctuations is fully consistent with the Hooke’s law route. Unlike existing methods, our approach relies on a single simulation, and no a priori knowledge of the bending modulus is required. We illustrate our method by analyzing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayers using the coarse grained MARTINI force-field. The area per lipid and area compressibility modulus obtained with our method and the MARTINI forcefield are consistent with previous studies of these bilayers.},
doi = {10.1063/1.4926938},
url = {https://www.osti.gov/biblio/22489731}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 3,
volume = 143,
place = {United States},
year = {Tue Jul 21 00:00:00 EDT 2015},
month = {Tue Jul 21 00:00:00 EDT 2015}
}