Affinities of clenbuterol/isoproterenol and their derivatives (all racemates, except (−)-isoproterenol) for wild-type and N293L mutant β2-adrenergic receptors
| Compound | Affinity | |
|---|---|---|
| Wild-type | N293L | |
| K i, μM | ||
| 1 ((±)-clenbuterol) | 0.024 ± 0.0081-a | 0.025 ± 0.0071-a |
| 2 | 3.3 ± 1.1 | 2.3 ± 0.4 |
| 3 | 3.1 ± 0.9 | 7.9 ± 1.8 |
| 4 | 1.6 ± 0.5 | 2.3 ± 0.2 |
| 5 ((−)-isoproterenol) | 0.28 ± 0.071-a | 2.5 ± 0.41-a |
| 6 | 28 ± 9.1 | 29 ± 1.2 |
| 7 | 39 ± 14 | 6.4 ± 1.1 |
| 8 | 12 ± 0.1 | 24.5 ± 1.6 |
The affinities were determined in competition experiments with 50 pM125I-CYP. The data were analyzed by nonlinear curve fitting to obtain estimates for the affinity. Data are means ± S.E.,n = 3.
↵1-a Data were taken from Wieland et al. (1996).