After initial energy minimization and equilibration runs, all atomistic simulations were run at a 2 fs time step. The LINCS algorithm was applied to constrain all, non-water, bonded hydrogens. Van der Waals forces were switched off smoothly from 1.0 to 1.2 nm, and electrostatics were computed using particle-mesh Ewald summation 76 . The particle neighbor list was updated using the Verlet list scheme. The system temperature was maintained at 310 K by coupling to a Nosé-Hoover thermostat with a 1 ps coupling constant, while pressure was coupled to 1.0 bar using a Parrinello-Rahman barostat (isotropically for aqueous systems, semi-isotropically for membrane systems) with a 5 ps coupling time. All atomistic simulations were run for at least 1 μs.