Fig. 1
From: Queueing arrival and release mechanism for K+ permeation through a potassium channel
Water–ion coupling ratio (CRw–i) as a function of the K+ concentration. Experimental CRw–i values as a function of [K+], taken from the literature, for three different potassium channels are shown: the human ether-à-go–go-Related Gene (hERG) [27], the inward rectifier (Kir2.1) [29], and the KcsA [28] channels (open circles). The concentration indicates the [K+] on both sides of the membrane. Our simulated CRw–i values are superimposed (red filled squares). CRw–i increased from 1.0 with a high [K+] to 2.0 at a low [K+]. Snapshots on the right show typical configurations of ions (green) and water molecules (red and white) in the SF (cyan) at the transition states, where CRw–i = 2 (upper panel) and 1 (lower panel). The arrows indicate the direction of the outward ion flux from the nanocavity side to the external side