Fig. 4.

Effect of the open–closed transition of OmpF on permeation of ions and antibiotics. (A, Upper) The cumulative net number of channel-crossing events by ions (Cl^–and Na⁺) tracked over the time course of a representative MD simulation for O (blue), C_A (black), and C_B (red) states. (A, Lower) Mean and SD of conductance for O (blue), C_A (black), and C_B (red) states determined using five independent constant electric-field simulations for each state. (B) Mean (solid) and SD (shaded) of the free energy for permeation of fosfomycin through O (blue) and C_A (black) states. Free energies were calculated using all the 94 MCPS BEUS windows and projected along the z coordinate of the antibiotic center of mass (C.O.M.), relative to the membrane C.O.M.