Figure 7.

The proposed kinetic scheme captures the main features of MthK Ca²⁺ and voltage-dependent gating. Simulated single-channel records using the kinetic model in Scheme 1 and the rate constants in Table I for two different Ca²⁺ concentrations (A), and two different voltages (B), for comparison with real data from Fig. 3 A and Fig. 5 A, respectively. Simulated data was filtered at 1–2 kHz and sampled at 10 kHz, just like the real data. (C) Predicted Ca²⁺ dose–response from the kinetic model in Scheme 1. Symbols represent Po values, mean ± SEM from four to seven distinct sets of 120 s of simulated single-channel data for each Ca²⁺ concentration. Solid line represents a Hill fit with Eq. 3 with n = 7.5 ± 0.5, K_d = 4 ± 0.04 mM, and P_o,max = 0.28.