Table 2.
Allosteric Ligands for Melanocortin Receptors.
| Compound | a Binding Affinities a IC50 (nM) | b Functional Assays cAMP EC50 (nM) | ||||||
|---|---|---|---|---|---|---|---|---|
| MC1R | MC3R | MC4R | MC5R | MC1R | MC3R | MC4R | MC5R | |
| 6. Ac-c[Cys-His-D-Phe-Nα-Gubu-Cys]-Trp-NH2c | NB | NB | 1.8 (50) | NB | NA | Na | NA | NA |
|
| ||||||||
| 7. Ac-c[Cys-His-D-Phe-Cys]-Nα-Gubu-D-Trp-NH2c | NB | NB | 0.7 (50) | NB | NA | NA | >1,000 | NA |
|
| ||||||||
8.
|
NB | NB | NB | 0.8 (50) | NA | NA | NA | NA |
|
| ||||||||
9.
|
40 (50) | 40 (50) | NB | NB | NA | NA | NA | NA |
a
Competitive binding of ligands vs [125I]-NDP-α-MSH;
b
Adenylate Cyclase Assay; Gubu = Guanidinylbutyl; NB= No binding at 10−5M; NA= No cAMP up to 10−5M ligand; In=Indole