A molecular dynamics study proposing the existence of statistical structural heterogeneity due to chain orientation in the POPC-cholesterol bilayer
| Autor: | Mauricio D. Carbajal-Tinoco, Fernando Favela-Rosales, Seiichiro Nakabayashi, Jorge Hernández-Cobos, Naritaka Kobayashi, Iván Ortega-Blake, Arturo Galván-Hernández |
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| Rok vydání: | 2019 |
| Předmět: |
Phase transition
030303 biophysics Lipid Bilayers Biophysics Molecular Dynamics Simulation Microscopy Atomic Force Biochemistry Phase Transition 03 medical and health sciences Molecular dynamics chemistry.chemical_compound Lipid bilayer POPC 030304 developmental biology 0303 health sciences Chemistry Bilayer Organic Chemistry Membrane structure Temperature Polyene Membrane Cholesterol Chemical physics Phosphatidylcholines lipids (amino acids peptides and proteins) |
| Zdroj: | Biophysical chemistry. 257 |
| ISSN: | 1873-4200 |
| Popis: | We performed molecular dynamics simulations of a lipid bilayer consisting of POPC and cholesterol at temperatures from 283 to 308 K and cholesterol concentrations from 0 to 50% mol/mol. The purpose of this study was to look for the existence of structural differences in the region delimited by these parameters and, in particular, in a region where coexistence of liquid disordered and liquid ordered phases has been proposed. Our interest in this range of concentration and temperature responds to the fact that polyene ionophore activity varies considerably along it. Two force fields, CHARMM36 and Slipids, were compared in order to determine the most suitable. Both force fields predict non-monotonic behaviors consistent with the existence of phase transitions. We found the presence of lateral structural heterogeneity, statistical in nature, in some of the bilayers occurring in this range of temperatures and sterol concentrations. This heterogeneity was produced by correlated ordering of the POPC tails and not due to cholesterol enrichment, and lasts for tens of nanoseconds. We relate these observations to the action of polyenes in these membranes. |
| Databáze: | OpenAIRE |
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