title: POPC with varying amounts of cholesterol, 450 mM of CaCl_2. Slipids with ECC-scaled ions
author: Javanainen, Matti
description: Simulations of a POPC bilayer with varying amounts (0, 10, 20, and 30 mol-%) of cholesterol and 450 mM of CaCl_2 performed at 310 K. The POPC bilayer consists of 200 lipids (100 per leaflet) and on top of that there is 0 (0%), 22 (10%), 50 (20%), or 86 (30%) of cholesterol. Additionally, simulations with 0% cholesterol are repeated at 330 K, 350 K, and 370 K. The Slipids model [1–3] is employed for lipids, tip3p model for water, and the recent ion parameters by Kohagen et al. [4] for CaCl_2. The Slipids force field parameters are available at http://www.fos.su.se/~sasha/SLipids/ and the ion parameters are available at https://bitbucket.org/hseara/ions/ –––––––––––––––––––––––––––––––––––––––––––––––––––––– The files are in GROMACS format and named based on the amount of cholesterol present (in %) in the corresponding simulation. Trajectories (.xtc) are 600 ns long (800 ns long for systems at elevated temperatures) with data saved every 100 ps. Additionally, the final structure (.gro), topology (.top), index file (.ndx), energy output file (.edr), and binary run input files (for Gromacs 4.6->) (.tpr) are provided for each system. The common simulation parameter file (.mdp) is also provided. –––––––––––––––––––––––––––––––––––––––––––––––––––––– [1] Derivation and Systematic Validation of a Refined All-Atom Force Field for Phosphatidylcholine Lipids. Joakim P. M. Jämbeck and Alexander P. Lyubartsev, The Journal of Physical Chemistry B 2012 116 (10), 3164-3179, DOI: 10.1021/jp212503e [2] An Extension and Further Validation of an All-Atomistic Force Field for Biological Membranes. Joakim P. M. Jämbeck and Alexander P. Lyubartsev, Journal of Chemical Theory and Computation 2012 8 (8), 2938-2948, DOI: 10.1021/ct300342n [3] Another Piece of the Membrane Puzzle: Extending Slipids Further. Joakim P. M. Jämbeck and Alexander P. Lyubartsev, Journal of Chemical Theory and Computation 2013 9 (1), 774-784, DOI: 10.1021/ct300777p [4] Accurate Description of Calcium Solvation in Concentrated Aqueous Solutions. Miriam Kohagen, Philip E. Mason, and Pavel Jungwirth, The Journal of Physical Chemistry B 2014 118 (28), 7902-7909, DOI: 10.1021/jp5005693