Binding of formylcholine to wild-type and TMD 5 mutant M1mAChRs
| Mutant | pIC50 | nH | Fold Effect | n |
|---|---|---|---|---|
| −log M | ||||
| WT | 3.39 ± 0.04 | 0.99 ± 0.02 | 5 | |
| I188C | 2.96 ± 0.102-150 | 1.00 ± 0.13 | 2.7 | 3 |
| I188A | 3.21 ± 0.07 | 0.95 ± 0.06 | 1.5 | 2 |
| T192C | 3.12 ± 0.082-150 | 0.94 ± 0.06 | 1.9 | 3 |
| T192A | 3.22 ± 0.07 | 0.96 ± 0.13 | 1.5 | 2 |
| A196C | 2.93 ± 0.062-150 | 1.01 ± 0.05 | 2.9 | 3 |
| A196G | 3.35 ± 0.18 | 0.89 ± 0.09 | 1.1 | 2 |
Formylcholine was dried to constant weight in a SpeedVac before use. To minimize the hydrolysis of FCh, competition binding assays were performed for 30 min at pH 7.5. Data were analyzed using the Hill equation to generate an IC50 value and a Hill coefficient,n H. Affinities have been corrected for the Cheng-Prusoff shift. Fold-effect is the decrease in FCh binding affinity compared with the wild-type level. Results are the mean ± range or S.E. of n determinations.
↵2-150 P < .01 with respect to wild-type control.