Dresden 2017 – wissenschaftliches Programm
CPP 43.2: Vortrag
Mittwoch, 22. März 2017, 15:15–15:30, ZEU 255
A Refined Polarizable Water Model for the Coarse-Grained MARTINI Force Field — •Julian Michalowsky1, Lars Schäfer2, Johannes Zeman1, Christian Holm1, and Jens Smiatek1 — 1Institute for Computational Physics, University of Stuttgart, Allmandring 3, D-70569 Stuttgart, Germany — 2Center for Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr-University, Universitätsstraße 150, D-44780 Bochum, Germany
We propose a refined version of the polarizable MARTINI water model designed for the use with long-range electrostatics. Our new model improves the resemblance of the experimentally measured water mass density at room temperature and matches the experimentally measured dielectric constant of water. Our investigations show that the new model performs stably with a variety of commonly used sets of simulation parameters, remaining fully applicable within a reaction field framework. The oil/water partitioning behavior of uncharged MARTINI beads is thoroughly investigated: Lennard-Jones interactions between our new model and the remaining MARTINI beads are tuned to reproduce the hydration free energies obtained with the original polarizable water model. The cross-interactions with charged bead types are matched to the experimentally observed area per lipid of a solvated dipalmitoylphosphatidylcholine (DPPC) lipid bilayer. We additionally analyzed the potentials of mean force between different sample pairs solvated in the refined polarizable water model and compared the results to reference data obtained using the original water model and atomistic approaches.