Figure 8.

mENaC containing α-subunits with I93C and H94C substitutions gate in a voltage-dependent manner. Families of representative single-channel current traces from CHO cells for recombinant mENaC containing αI93C (A) and αH94C (B) in outside-out patches stepped from 80 mV to −80 mV. The bath and pipette [Li⁺] were symmetrical for these experiments. Inward Na⁺ current is downward; C, closed state. (C) Plot showing ENaC P_o as a function of voltage for wild-type (black squares) and mutant mENaC containing αW112C (open circles), αI93C (open squares), or αH94C (black circles). Data were fit by the Boltzmann equation and obtained from experiments identical to that shown in panels A and B; n ≥ 4 for each group.