TABLE III.
Affinity Constants for A713X Homomeric Channels
| K i' @ −60 mV | K i' (0 mV) | δ | ΔG° | |
|---|---|---|---|---|
| μM | μM | kJ/mol | ||
| Amiloride | ||||
| A713wt | 0.76 ± 0.16 (5) | 2.28 ± 0.60 | 0.47 ± 0.05 | −31.9 |
| A713G | 1.89 ± 0.10 (6)a | 6.50 ± 0.56 | 0.54 ± 0.04 | −29.3 |
| A713C | 0.51 ± 0.01 (6) | 1.86 ± 0.09 | 0.55 ± 0.01 | −32.4 |
| A713T | 2.35 ± 0.39 (7)a | 8.47 ± 0.96 | 0.53 ± 0.05 | −28.6 |
| A713D | 2.10 ± 0.15 (8)a | 6.24 ± 0.36 | 0.46 ± 0.01 | −29.4 |
| A713V | 0.95 ± 0.17 (6) | 2.96 ± 0.41 | 0.52 ± 0.01 | −31.2 |
| A713C+MTSES | 0.59 ± 0.07 (6) | 1.51 ± 0.22 | 0.36 ± 0.03 | −32.9 |
| Benzamil | ||||
| A713wt | 0.15 ± 0.01 (8) | 0.28 ± 0.03 | 0.26 ± 0.06 | −37.0 |
| A713T | 0.83 ± 0.14 (5)a | 2.62 ± 0.03 | 0.56 ± 0.03b | −31.5 |
| Benzamidine | ||||
| A713wt | 108 ± 3 (4) | 576 ± 71 | 0.73 ± 0.01 | −18.3 |
| A713T | 196 ± 40 (7) | 497 ± 87 | 0.40 ± 0.05b | −18.7 |
Affinity constants, K i', given as mean ± SEM (n). One-way ANOVA for K i(−60 mV) (excluding A713C channels treated by MTSES): amiloride, F(5,32) = 12.73, P < 1e-06; benzamil, F(1,11) = 39.03, P < 0.0001; benzamidine, F(1,9) = 3.30, P = 0.103. One way ANOVA for δ: amiloride, F(5,32) = 1.78, P = 0.15; benzamil, F(1,11) = 15.04, P < 0.005; benzamidine, F(1,7) = 19.18, P < 0.005.
a
P < 0.01; pairwise Dunnet's test with respect to wild type in each dataset.
b
P < 0.005; pairwise Dunnet's test with respect to wild type in each dataset.