Current and selectivity in a model sodium channel under physiological conditions: Dynamic Monte Carlo simulations

► Selectivity and permeation in model sodium channel studied with Dynamic Monte Carlo. ► Ion permeation is single ion moving by simple diffusion. ► Model reproduces Na+ vs. K+ selectivity, Ca2 + exclusion, DEKA to DEEE mutations. ► Na+ vs. K+ selectivity: K+ excluded from crowded pore and moves slower through pore. ► Point mutations DEKA → DEEE make calcium channel, reproducing experiments.