Table 2.
Estimated IC50 values and Hill coefficients based on inhibition of Bgt binding to cell surface PC12, α7/5HT3 and mouse muscle receptors by different cholinergic ligands
| PC12 BgtRs | α7/5HT3homomers | α2βεδ AChRs | |||||||
|---|---|---|---|---|---|---|---|---|---|
| IC50 (m) | Hill coefficient | n | IC50 (m) | Hill coefficient | n | IC50 (m) | Hill coefficient | n | |
| Agonist | |||||||||
| ACh | 2.6 ± 0.1 × 10−4 | 2.4 ± 0.2 | 4 | 3.2 ± 0.3 × 10−4 | 2.4 ± 0.3 | 4 | – | – | – |
| Carbachol | 1.2 ± 0.1 × 10−4 | 2.3 ± 0.3 | 2 | 3.8 ± 0.2 × 10−3 | 2.1 ± 0.2 | 2 | 4.2 ± 0.1 × 10−4 | 1.5 ± 0.06 | 2 |
| Cytisine | 1.5 ± 0.1 × 10−5 | 2.3 ± 0.3 | 3 | 4.8 ± 0.2 × 10−6 | 2.6 ± 0.3 | 3 | – | – | – |
| Nicotine | 5.0 ± 0.3 × 10−5 | 2.4 ± 0.2 | 3 | 4.2 ± 0.2 × 10−6 | 2.1 ± 0.1 | 3 | – | – | – |
| Antagonist | |||||||||
| dTC | 4.8 ± 0.5 × 10−6 | 0.99 ± 0.08 | 2 | 2.7 ± 0.3 × 10−6 | 1.1 ± 0.1 | 2 | 3.9 ± 0.5 × 10−7 | 0.69 ± 0.05 | 2 |
| MLA | 3.5 ± 0.3 × 10−9 | 1.0 ± 0.07 | 2 | 3.5 ± 0.3 × 10−8 | 1.5 ± 0.2 | 3 | – | – | – |
IC50, Hill coefficients, and error estimates were obtained from least-squares fits of the following equation to the data: (Max.)/(1 + ([ligand]/IC50))n, where n is the Hill coefficient (see Fig. 7A, B). n is the number of separate experiments.