Temperature and pressure were kept constant at 310 kelvin and 1 bar using the v-rescaling thermostat (τ t = 1 ps) and the Parrinello-Rahman barostat (τ p = 12 ps). The crescale barostat 51 (τ p = 4 ps) was used for equilibration. Semi-isotropic pressure coupling was used for the membrane systems. Compressability was set to 3 × 10 -4 . All systems were first minimized and equilibrated for 10 ns with restraints on the protein backbone beads.