Table 2. Potency of m3-HwTx-IV on hNaV1.1–1.8 stably expressed in HEK239 or CHO cells using whole-cell patch-clamp electrophysiology in QPatch and heterologously expressed in HEK293 cells assessed using FLIPR membrane potential assay.
Data are presented as IC50 mean ± SD.
| Subtype | IC50 (nM) QPatch | IC50 (μM) FLIPR |
|---|---|---|
| hNaV1.1 | 8.4 ± 1.8 (n = 4) | 1.1 ± 0.7 |
| hNaV1.2 | 11.9 ± 2.2 (n = 6) | 0.54 ± 0.4 |
| hNaV1.3 | 7.2 ± 1.6 (n = 3) | 1.4 ± 0.6 |
| hNaV1.4 | 369 ± 196 (n = 6) | >30 |
| hNaV1.5 | >1000 (n = 5) | >30 |
| hNaV1.6 | 6.8 ± 1.5 (n = 7) | 0.60 ± 0.6 |
| hNaV1.7 | 3.3 ± 1.1 (n = 4) | 5.1 ± 4 |
| hNaV1.8 | > 1000 (n = 11) | >30 |
In parallel, the full selectivity profile of m3-HwTx-IV at all hNaV1 channel subtypes heterologously expressed in HEK293 cells was measured using a FLIPR membrane potential assay, which yielded IC50 values of: hNaV1.1, 1.1 ± 0.7 μM; hNaV1.2, 0.54 ± 0.4 μM; hNaV1.3, 1.4 ± 0.6 μM; hNaV1.4, >30 μM; hNaV1.5, >30 μM; hNaV1.6, 0.60 ± 0.6 μM; hNaV1.7, 5.1 ± 4 μM; hNaV1.8, >30 μM (Table 2), supporting the selectivity data obtained using whole-cell patch-clamp electrophysiology.