Molekulardynamik-Untersuchung der Auswirkung von Additiven auf die Fluidität von Lipidmembranen
Zusammenfassung der Projektergebnisse
Using a water-solvated membrane of DPPC as a model system, we have demonstrated that the transmembrane transport of three conserved quantities (matter, momentum and energy) can be simulated successfully with different variants of nonequilibrium molecular dynamics. In particular, the corresponding transport coefficients can be resolved locally. This allows assessing the resistance to transport offered by the different regions of the membrane: water, head groups, alkyl chains, and membrane centre. Different regions are important for the different transported quantities. Permeating particles are held up in the head group areas, while they quickly cross the alkyl region. Momentum, in turn, passes quickly through head groups and alkyl tails, but is slowed down where the chains from both membrane sides touch each other. This introduces a glide plane at the membrane centre, so the two leaves of the membrane glide over each other, for example, when the membrane curvature changes during endocytosis. Finally, the membrane centre is also the biggest obstacle to heat transport through the water-membrane aggregate. Models of thermal conduction through tissue would have to take this into account.
Projektbezogene Publikationen (Auswahl)
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“The influence of thermostats and manostats on reverse non-equilibrium molecular dynamics calculations of fluid viscosities”. J. Chem. Phys. 129, 014102 (2008)
T. J. Müller, M. Al-Samman, and F. Müller-Plathe
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“A Comparison of Sulfur Mustard and Heptane Penetrating a Dipalmitoylphosphatidylcholine Bilayer Membrane”. J. Hazard. Mater. 168, 13-24 (2009)
T. J. Müller and F. Müller-Plathe
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“Determining the Local Shear Viscosity of a Lipid Bilayer System by Reverse Non-Equilibrium Molecular Dynamics Simulations”. ChemPhysChem 10, 2305-2315 (2009)
T. J. Müller and F. Müller-Plathe
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“Transportphänomene in biologischen Membranen: Simulation von Massen-, Impuls- und Wärmetransport“. Dissertation, TU Darmstadt, 14. 12. 2009
Thomas Müller
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“Heat Transport through a Biological Membrane – an Asymmetric Property? Technical Issues of Non-equilibrium Molecular Dynamics Methods”. Int. J. Quant. Chem. 111, 1403–1418 (2011)
T. J. Müller and F. Müller-Plathe