Sodium channels selectively conduct Na⁺ ions across cellular membrane with extraordinary efficiency, which is essential for initiating action potentials. However, how Na⁺ ions permeate the ionic channels remains obscure and ambiguous. With more than 40 conductance events from microsecond molecular dynamics simulation, the soft knock-on ion permeation mediated by water molecules was observed and confirmed by the free energy profile and electrostatic potential calculation in this study. During the soft knock-on process, the change of average distance between four oxygen atoms in Glu177-Glu177 plays a very important role for the permeation of Na⁺ ion. Exploration of the ionic conductance mechanism could provide a guideline for designing ion channel targeted drug.

钠通道选择性地将 Na ⁺离子以非凡的效率穿过细胞膜，这对于启动动作电位至关重要。然而，Na ⁺离子如何渗透离子通道仍然模糊不清。通过来自微秒分子动力学模拟的 40 多个电导事件，本研究中的自由能分布和静电势计算观察到并证实了由水分子介导的软碰撞离子渗透。在软敲击过程中，Glu177-Glu177中四个氧原子平均距离的变化对Na ⁺的渗透起着非常重要的作用离子。离子电导机制的探索可以为设计离子通道靶向药物提供指导。