Fig. 4
From: Queueing arrival and release mechanism for K+ permeation through a potassium channel
Time spent in spontaneous release, knock-on, waiting periods, and a queueing permeation model. a Distribution of entry times to the SF (en-queueing time; left boxes) and exit times of the outermost ion from the SF (de-queueing time; right boxes) for different [K+]. Zero time (Δt = 0) is set to coincide with the SF-in for I0. The dots represent raw data, and the distributions denote their kernel density estimation. The upper panel represents a two-ion-occupied SF before the SF-in, and the lower panel represents a one-ion-occupied SF. b Rates from the two-ion-occupied state to the one- (red) and three-ion-occupied (black) states. The black dashed line represents a linear fit for the data (rate = [K+]·0.33 ns−1), and the red dashed line is a fit calculated from a constant (0.021 ns−1). c The queueing model. The ions in the SF are shown by green circles. During the long-elapsed time frame for spontaneous release, two water molecules follow and are then intercalated between ions upon the next SF-in, which is measured as CRw–i = 2