Figure 5.

Extracellular trivalent cations reduce unitary conductance and open probability of the NSC channel. a, Effects of 1 mm GdCl₃ or 1 mm LaCl₃, applied to the cis face, on single channel current, in 100 mm NaCl:100 mm KCl + 5 mm TES-BTP, pH 7.4, cis/trans. b, Inclusion of 1 mm Gd³⁺ in the cis solution reduced P_max and shifted the voltage dependence of channel opening from E_0.5 = −139 mV in the control to E_0.5 = −67 mV (data are fitted with modified Boltzmann equations: gating charge was 0.82 and 1.17, respectively).