The physical basis of ion channel kinetics: The importance of dynamics

Ions cross the cell membrane through ion channel proteins. The traditional approaches have analyzed channel proteins as if they existed in a few stable conformations and switched rapidly between them. However, we show here the importance of dynamical properties in these proteins. These properties include continuous internal motions and continuous changes of state, the interactions of the ions with themselves and with the channel protein, deterministic forces, and time-dependent molecular memory. This new dynamical perspective changes how we interpret experimental data from patch clamp experiments that record the ionic currents through individual channels. It also helps us to understand how ion channel proteins function as molecular machines and how their molecular properties are related to their physiological function.