Figure 3.

Voltage-dependent block of AKT3 by extracellular Ca²⁺. (A) Tail currents elicited by voltage pulses to −130, −110, −160, and −170 mV after prepulses to −150 mV were recorded in the presence of 30 mM Ca²⁺. (B) Relative instantaneous tail current amplitudes I_o plotted against the voltage revealed a voltage- and concentration-dependent block by Ca²⁺ (n = 3). The lines represent best fits according to the Woodhull model (16). The solutions contained 20 mM KCl, 10 mM Tris/Mes (pH 7.2), and CaCl₂ as indicated. CaCl₂ was replaced by same concentrations of MgCl₂.