TABLE 3.
IVST and EC50 of WT and mutant channels in the presence of CssIVE15A
IVST is the normalized voltage-sensor trapping current observed at a test pulse to −60 mV following a prepulse (see text). For channels in which saturating effects of CssIVE15A could be recorded, KD values were calculated from fitting the data to the voltage-sensor trapping model. IVST data are presented as mean ± S.E.
| Channel | Concentration | IVST (+Pre) | n | EC50 |
|---|---|---|---|---|
| nm | nm | |||
| WT | 50 | 3.2 ± 1.7% | 3 | 1100 |
| 100 | 5.0 ± 0.9% | 8 | ||
| 200 | 7.9 ± 1.0% | 6 | ||
| 500 | 16.2 ± 2.6% | 5 | ||
| 1,000 | 28.0 ± 4.3% | 4 | ||
| 2,000 | 44.8 ± 1.0% | 5 | ||
| 5,000 | 48.9 ± 3.9% | 10 | ||
| 10,000 | 54.2 ± 5.5% | 3 | ||
| N1436G | 20 | 9.24 ± 1.0% | 6 | 274.2 |
| 50 | 11.5 ± 2.5% | 4 | ||
| 100 | 17.5 ± 2.9% | 9 | ||
| 200 | 28.5 ± 2.8% | 12 | ||
| 500 | 38.2 ± 3.8% | 7 | ||
| E1438A | 500 | 3.7 ± 0.54% | 7 | NAa |
| L1439A | 100 | 6.6 ± 1.8% | 7 | 1071.5 |
| 200 | 17.4 ± 2.1% | 5 | ||
| 500 | 31.3 ± 6.6% | 5 | ||
| 1,000 | 38.0 ± 4.6% | 8 | ||
| 2,000 | 59.7 ± 3.9% | 4 | ||
| 5,000 | 71.6 ± 6.7% | 4 | ||
| D1445A | 500 | 4.8 ± 0.7% | 4 | NA |
| D1445Y | 500 | 0.4 ± 0.3% | 5 | NA |
a NA, not applicable.