All energy minimizations and MD simulations were performed using pmemd and pmemd.cuda programs of Amber 18. Periodic boundary conditions were used with a 9.0 Å cutoff for real space nonbonded interactions, PME for long-range electrostatics, and an analytic correction for long-range van der Waals interactions. First, each system was minimized with 250 steps of steepest descent minimization, followed by 250 steps of conjugate gradient minimization.