Figure 4.

Mathematical model of g_j changes in response to pH_i under different [Mg²⁺]_i. (A) Hypothetical g_j-pH_i curves fitted to experimental data. Blue triangles denote g_j values at [Mg²⁺]_p = 5 mM, green squares—at [Mg²⁺]_p = 1 mM, and red circles - at [Mg²⁺]_p = 0.01 mM. The theoretical g_j-pH_i plots were obtained from the Equation (2). (B,C) shows theoretical open channel probabilities in response to acidic gating (B) and alkalic gating (C), which were estimated from (1). Red, green and blue lines denote g_j-pH_i dependence at [Mg²⁺]_i = 0.01, 1, and 5 mM, respectively. (D–L) show the same results as (A–C) with Cx36 mutants.