Effect of various Panx1 inhibitors in alanine replacement mutants lacking the feedback inhibition by ATP. The Panx1 inhibitors carbenoxolone, BB FCF, Fast Green FCF, and probenecid were tested in wild-type Panx1 and various alanine replacement mutants using the same protocol as in Fig. 2. The inhibition by probenecid was almost abolished in Panx1 W74A. Carbenoxolone and Fast Green FCF inhibited the currents effectively in all mutants. BB FCF inhibition was attenuated in all mutants except Panx1 I247A. Means ± SD are plotted. n = 5 for Panx1 I247A and L266A, and n = 4 for all other points.