MD simulations of A (blue) and B (magenta) conformations of NaK2K. (a), (b) Ionic currents through NaK2K at the membrane voltages of 300 (a) and −300 mV (b). Each dot represents an independent 500 ns long MD simulation. (c), (d) An average number of potassium ions found in the cavity (ions within 0.6 nm of the center of mass of Phe92 were considered), at 300 and −300 mV, respectively. (e), (f) Pore radius profiles for simulations at 300 and −300 mV, respectively. The horizontal purple line marks the typical radius of a fully hydrated potassium ion. The average position of the Phe92 aromatic ring is also indicated, as well as the selectivity filter. The error bars indicate 95% confidence intervals.