Table 2.
Comparison of the biophysical and pharmacological properties of native NBCe current and NBCe1-B current
| Native NBCe current | NBCe1-B current | |
|---|---|---|
| Relative cation selectivity | Na+≫ Li+ > K+ > choline ≈ NMDG ≈ Cs+ | Na+≫ K+≈ choline ≈ Li+≈ NMDG ≈ Cs+ |
| Na+o dependency | Yes | Yes |
| Apparent Km of Na+o at +50 mV | 20.8 ± 1.0 mm | 21.1 ± 1.2 mm |
| Voltage dependency of Km | No | No |
| Stoichiometry (q) | 2.2 ± 0.1 | — |
| DIDS block | Yes | Yes |
| Ki(0) of DIDS | 0.22 ± 0.06 mm | 0.18 ± 0.05 mm |
| Hill coefficient at 0 mV | 1.05 ± 0.04 | 0.97 ± 0.05 |
| Ki decrease e-fold per | 67.9 ± 2.4 mV depolarization | 54.3 ± 7.4 mV depolarization |
| Blocking of other anion channel | ||
| blockers (0.1 mm) at –40 mV | ||
| Phloretin | Yes | — |
| NFA | Yes | Yes |
| NPPB | Yes | Yes |
| Glybenclamide | Yes | Yes |
| DPC | No | No |
Values are means ±s.e.m. of 4–9 experiments.