Table 1.
Summary of the amantadine sensitivity of the A/M2 pore lining mutants.
| Mutant | Activity (%) after inhibition with 100 μM amantadine | S.D. | Activity (%) after 5 min recovery from inhibition | S.D. |
|---|---|---|---|---|
| A/M2 | 6.0 | 1.4 | 11 | 2.1 |
| V27A | 97.5 | 4.2 | 100 | |
| V27D | 59.1 | 5.9 | 100 | |
| V27W | 13.1 | 1.9 | 100 | |
| V27G | 98.7 | 6.8 | 100 | |
| V27T | 26.5 | 4.3 | 100 | |
| V27K | 60.7 | 7.6 | 100 | |
| V27S | 95.9 | 3.3 | 100 | |
| V27R | 96.1 | 4.2 | 100 | |
| V27F | NF | |||
| A30D | 102.6 | 6.5 | 100 | |
| A30T | 106.0 | 8.5 | 100 | |
| A30G | 82.3 | 2.2 | 100 | |
| A30F | NF | |||
| A30K | NIS | |||
| S31N | 65.4 | 8.3 | 95.6 | 7.2 |
| S31A | 17.0 | 5.2 | 50.4 | 0.6 |
| S31G | 16.3 | 1.8 | 90.2 | 1.8 |
| S31T | 74.0 | 6.8 | 93.7 | 1.6 |
| S31D | 64.5 | 4.4 | 100 | |
| S31K | 86.1 | 20.5 | 100 | |
| S31F | NF | |||
| G34A | 72.7 | 8.4 | 100 | |
| G34E | 82.3 | 9.6 | 100 | |
| G34T | 42.0 | 1.9 | 36.5 | 2.1 |
| G34K | 102.6 | 6.5 | 100 | |
| G34F | NF | |||
| G34V | NF | |||
| G34L | NF | |||
| H37A | NIS | |||
| H37S | NIS | |||
| H37G | NIS | |||
| H37K | NIS | |||
| H37N | NIS | |||
| H37F | NIS | |||
| H37D | NIS | |||
| H37Q | NIS | |||
| W41A | 42.5 | 9.8 | 67.1 | 3 |
| W41G | 16.9 | 5.6 | 20.5 | 8.6 |
| W41Y | 16.8 | 0.7 | 20.8 | 1.1 |
| W41F | 67.3 | 5.4 | 81.9 | 4.4 |
| W41D | NIS | |||
| W41K | NIS | |||
| D44A | 13.3 | 5.3 | 24.1 | 1.1 |
| D44K | 12.1 | 4.8 | 16 | 9.1 |
| D44N | 7.0 | 0.3 | 19.4 | 1.5 |
| D44F | 11.7 | 2.5 | 18.8 | 1.9 |
| D44G | 7.2 | 0.7 | 20.8 | 0.1 |
| D44T | 20.3 | 2.7 | 22.8 | 4.3 |
A/M2 wt and mutant channels expressed in Xenopus oocytes were activated by acidification (pH 5.5) and exposed to 100 μM amantadine in the bathing solution (pH 5.5) for 2 min. The remaining channel activity was measured and normalized to the channel activity before the application of the inhibitor. To test the rate of the reversibility of amantadine inhibition, the channel activity was re-assayed again after the oocyte was bathed in the pH 8.5 solution for 5 min. The values are the mean (±SD) from measurements from 10-15 oocytes from 3-6 independent experiments. NF stands for “non functional”. NIS stands for “not ion selective”.