Table 1.
Concentration–response parameters of wild-type, hybrid and mutant αY93F and αW149F receptors activated by ACh
| Receptor | Po,max | EC50 (μm) | n | β (s−1) | EC50 (μm) | n |
|---|---|---|---|---|---|---|
| Wild-type | 0.96 ± 0.04 | 29 ± 3 | 1.8 ± 0.3 | 60 000 | 448 ± 52 | 1.7 ± 0.07 |
| αY93F hybrid | 0.69 ± 0.02 | 224 ± 13 | 1.9 ± 0.2 | 5657 ± 853 | 686 ± 180 | 1.4 ± 0.1 |
| αY93F mutant | 0.42 ± 0.08 | 1123 ± 357 | 1.8 ± 0.8 | 1239 ± 269 | 2738 ± 14 | 1.1 ± 0.03 |
| αW149F hybrid | 0.63 ± 0.06 | 698 ± 160 | 1.5 ± 0.5 | 3337 ± 337 | 958 ± 165 | 1.9 ± 0.2 |
| αW149F mutant | 0.26 ± 0.02 | 2309 ± 261 | 3.6 ± 1.4 | 648 ± 93 | 3521 ± 630 | 2.1 ± 0.2 |
Cluster open probability (Po) and the effective opening rate (β′) were fitted using eqn (1) on data from Figs 2 and 4. The values for the wild-type receptor are from Akk & Auerbach (1996). The values for the mutant αY93F receptor are from Akk & Steinbach (2000). The opening rate constant for the wild-type receptor is from Maconochie & Steinbach (1998). The values are best-fit parameters ± standard deviation estimated from the fit.