Effect of Gs peptidomimetics on the cAMP accumulation induced by isoproterenol (ISO) at the β2-adrenergic receptor (β2AR) in a cell membrane-based cyclic adenosine monophosphate (cAMP) accumulation assay. Basal cAMP level, maximum efficacy, pEC50(−log(EC50)) and Hill slope of the concentration–response curve of ISO in absence and presence of 100 μM peptidomimetic (10 μM for 8C) were calculated by non-linear regression using GraphPad Prism. Nb80 was tested at 10 μM. Data are given as mean values of n number of experiments ± SEM. Significance level P < 0.05 (*) calculated by statistical analysis with a one-way ANOVA in GraphPad Prism.
| Peptide | Basal level | Maximum efficacy | pEC50 | Hill slope | n |
|---|---|---|---|---|---|
| Vehicle | 0.0 ± 0.0 | 100.0 ± 0.0 | 8.64 ± 0.03 | 0.81 ± 0.05 | 6 |
| Nb80 | −1.2 ± 0.7 | 11.3 ± 0.6* | 8.98 ± 0.16 | 0.88 ± 0.29 | 3 |
| 6A | 0.7 ± 1.1 | 90.8 ± 6.0 | 8.68 ± 0.04 | 0.81 ± 0.07 | 3 |
| 6B | −2.9 ± 4.2 | 81.5 ± 4.5 | 8.48 ± 0.08 | 0.81 ± 0.12 | 3 |
| 6C | 4.6 ± 1.9 | 89.7 ± 1.5 | 8.33 ± 0.02 | 0.83 ± 0.06 | 3 |
| 7A | −0.5 ± 1.5 | 88.8 ± 8.0 | 8.74 ± 0.01 | 0.83 ± 0.10 | 3 |
| 7B | −4.2 ± 1.8 | 79.9 ± 2.0* | 8.58 ± 0.03 | 0.84 ± 0.04 | 3 |
| 7C | 8.4 ± 4.3 | 88.1 ± 3.6 | 8.17 ± 0.11 | 0.87 ± 0.06 | 3 |
| 8A | −1.1 ± 0.7 | 97.7 ± 5.3 | 8.67 ± 0.04 | 0.72 ± 0.02 | 3 |
| 8B | −8.8 ± 2.8 | 77.1 ± 3.9* | 8.46 ± 0.15 | 0.82 ± 0.07 | 3 |
| 8C | −3.7 ± 2.3 | 78.0 ± 5.2* | 8.65 ± 0.06 | 0.71 ± 0.07 | 3 |
| 9A | 0.4 ± 0.7 | 92.7 ± 7.5 | 8.73 ± 0.08 | 0.83 ± 0.04 | 3 |
| 9B | 3.3 ± 4.6 | 84.1 ± 2.4 | 7.05 ± 0.38* | 0.89 ± 0.05 | 3 |
| 9C | 5.7 ± 2.1 | 88.1 ± 4.5 | 8.21 ± 0.33 | 0.92 ± 0.06 | 3 |
| 10A | 3.0 ± 0.4 | 82.8 ± 3.3 | 8.67 ± 0.05 | 0.78 ± 0.03 | 3 |
| 10B | −5.0 ± 2.6 | 80.5 ± 2.2 | 8.45 ± 0.04 | 0.72 ± 0.05 | 3 |
| 10C | −11.0 ± 4.3 | 61.0 ± 4.1* | 7.87 ± 0.01 | 0.63 ± 0.06 | 3 |
| 11A | −1.4 ± 0.7 | 90.7 ± 4.6 | 8.53 ± 0.05 | 0.74 ± 0.03 | 3 |
| 11B | −5.8 ± 3.0 | 88.0 ± 4.1 | 8.46 ± 0.07 | 0.72 ± 0.06 | 3 |
| 11C | −1.9 ± 8.4 | 78.4 ± 2.6* | 8.10 ± 0.12 | 0.85 ± 0.06 | 3 |
| 12A | 0.6 ± 0.4 | 94.5 ± 6.3 | 8.68 ± 0.03 | 0.73 ± 0.04 | 3 |
| 12B | −2.8 ± 4.0 | 74.0 ± 3.3* | 7.87 ± 0.53 | 0.88 ± 0.09 | 3 |
| 12C | −6.0 ± 2.1 | 71.7 ± 3.0* | 8.52 ± 0.05 | 0.90 ± 0.06 | 3 |
| 13A | 2.4 ± 0.3 | 90.0 ± 6.4 | 8.71 ± 0.05 | 0.85 ± 0.03 | 3 |
| 13B | 7.1 ± 5.7 | 85.1 ± 3.0 | 7.72 ± 0.30* | 0.89 ± 0.04 | 3 |
| 13C | 2.3 ± 1.2 | 82.8 ± 3.8 | 8.46 ± 0.43 | 0.80 ± 0.04 | 3 |