FIGURE 4.

Constant efficacy of AMI inhibition on acid (pH 5.0)-induced currents from ASIC3 mutants at Glu-79 or Glu-423. A, representative current traces showing AMI inhibition of the pH 5.0-induced currents from WT, E79A, and E423A mutant channels. B, pooled data from experiments in A. The inhibition ratio of AMI was quantitatively calculated as follows: ((1 − I_{AMI + pH 5.0}/I_{pH 5.0})·100) where I_{AMI + pH 5.0} and I_{pH 5.0} are the pH 5.0-induced currents measured in the presence or absence of AMI. Data points are means ± S.E. of four to seven measurements. There is no significant difference in the degree of inhibition by either 100 or 300 μm AMI among WT, E79A, and E423A groups. The WT data, taken from Fig. 1B, are regraphed again for comparison.