Fig. 3. Functional properties displayed by Zn²⁺ and H⁺ at WT ZAC (ZAC^Thr128) expressed in oocytes.

A. Agonist properties of Zn²⁺. Representative traces for Zn²⁺-evoked currents (left) and averaged concentration-response relationship displayed by Zn²⁺ at ZAC (means ± S.E.M., n = 6) (right). B. Agonist properties of H⁺. Representative traces for H⁺-evoked currents (left) and averaged “low-potency” and “high-potency” concentration-response relationships displayed by H⁺ at ZAC (right) (means ± S.E.M., n = 6–7) (right). The “low-potency” and “high-potency” data are normalised to the I_pH 3.5 value and to the fitted I_max value, respectively. C. Representative traces for currents evoked by prolonged applications of Zn²⁺ (1 mM) and H⁺ (pH 4.5) at ZAC. D. Current-voltage (IV) relationship of Zn²⁺-evoked currents through ZAC. Representative traces for currents evoked by prolonged application of Zn²⁺ (1 mM) at different holding potentials (left) and averaged IV relationship exhibited by Zn²⁺ (1 mM) at ZAC (right). Current amplitudes are plotted against clamped holding potentials, and data are given as leak-subtracted average current amplitudes normalised to the amplitude of currents recorded at − 60 mV (mean ± S.E.M., n = 6).