Figure 5.

I_Ba and I_Ca traces of selected α_1C constructs. A 400-ms pulse was applied from V_h = −90 mV to potentials that evoked approximately maximal I_Ba at +20 mV for 77, 77d20, 77d30, 77d10, 77d50, and at +30 mV for 77d68, 77d42, and 77d08. After switching from a 40 mM Ba²⁺- to 40 mM Ca²⁺-containing solution, the same TPs were applied. I_Ca traces were scaled to the amplitude of the corresponding I_Ba trace to compare time courses of I_Ba and I_Ca. Deletions of C-terminal amino acid residues between positions 1572 and 1651 for each construct are shown above each pair of current traces. Stretches of amino acids in the sequences 1572–1584 and 1614–1631 that were found to be important for Ca²⁺-dependent inactivation in each construct (Fig. 1) are underlined.