FIGURE 3.

H⁺, Ca²⁺, and Cl⁻ concentration-dependent acceptor/donor ratio and Ef_DA/γ of CEPAC* and EPAC*. A and B, pH sensitivity; C and D, Ca²⁺ sensitivity with (blue) and without (black, gray) proton-carried indirect calcium-effect; E and F, Cl⁻ sensitivity. The first graph column (A, C, and E) shows the normalized acceptor/donor ratio, and the second graph column (B, D, and F) shows the value Ef_DA/γ for EPAC* (black or dark blue) and CEPAC* (gray or light blue). Dependences were fitted using a Hill equation (dashed lines). Displayed values are mean and S.E. (error bars) calculated by using the results of the donor and acceptor unmixed components partly presented in Fig. 2. Fitting results and numbers of experiments are presented in Table 1.