Comparative analysis of MD up-to-down transition rates for WT and R-to-Q mutations in VSD _I and VSD _II . (A) Dynamic behaviors of VSD_I transitions, showing WT (black), R219Q (blue), R222Q (green), and R225Q (red). (B) Dynamic behaviors of VSD_II transitions, showing WT (black), R808Q (blue), R811Q (green), and R814Q (red). Data points represent results from three independent simulation runs, depicted by filled circles, empty squares, and filled squares. All simulations begin in the up state (light blue) under an applied external electric field of −500 mV, with transitions observed toward the intermediate state (orange) and down state (gray).