Fig. 6.

Macroscopic current rectification and anion selectivity in Y914 and Y917 mutant channels. a Example macroscopic current (I)–voltage (V) relationships recorded from inside-out patches under symmetrical high (154 mM) [Cl⁻] conditions, for the CFTR variants named. b Example I–V relationships (normalized to current at the most negative voltage) for these same CFTR variants, recorded (from different patches) with Cl⁻-containing or SCN⁻-containing intracellular (bath) solutions as indicated. Note that the current reversal potential (V_REV) is ~ 0 mV with Cl⁻-containing solutions but considerably more positive with SCN⁻-containing solutions, indicating a high relative SCN⁻ permeability. c Mean rectification ratio (current amplitude at − 80 mV/current amplitude at + 80 mV) measured from individual I–V relationships recorded under symmetrical high [Cl⁻] conditions such as those shown in a. Asterisks indicate a significant difference from wild-type (p < 0.02). d Mean relative SCN⁻ permeability (P_SCN/P_Cl) quantified from V_REV measured from individual I–V relationships such as those shown in b. Asterisks indicate a significant difference from wild-type (p < 0.02). Mean of data from 4 to 7 patches in c, d