Table 1.
Kd and Ki values (mean ± SEM) obtained from saturation and competition curves, respectively, for human and lamprey melanocortin peptide analogues binding lamprey MCa receptor and human MC1, MC3, MC4 and MC5 receptors. * P < 0.01
| lamprey MCa | human MC1a | human MC3e | human MC4e | human MC5b | |
| Ligand | (nmol·L-1) | (nmol·L-1) | (nmol·L-1) | (nmol·L-1) | (nmol·L-1) |
| [125I] NDP-MSH (Kd) | 2.46 ± 0.68 | 0.109 ± 0.062 | 0.412 ± 0.121 | 1.78 ± 0.36 | 5.05 ± 1.00 |
| NDP-MSH (Ki) | 17.8 ± 9.9 | 0.046 ± 0.011 | 0.319 ± 0.064 | 1.96 ± 0.39 | 2.39 ± 0.10 |
| α-MSH (Ki) | 248 ± 59* | 0.210 ± 0.089 | 21.2 ± 5.3 | 522 ± 122 | 8240 ± 1670 |
| β-MSH (Ki) | 54.7 ± 5.1 | 2.53 ± 0.93 | 15.1 ± 3.4 | 387 ± 208 | 14400 ± 1670 |
| γ1-MSH (Ki) | 684 ± 7* | 2.68 ± 0.35b | 7.45 ± 2.55 | 51800 ± 12000 | 42600 ± 6600 |
| ACTH (1–17) (Ki) | 51.1 ± 3.2 | 0.230 ± 0.061c | 14.0 ± 4.5c | 419 ± 62c | 4240 ± 1200c |
| ACTH (1–24) (Ki) | 56.4 ± 10.8 | 0.209 ± 0.052c | 32.8 ± 6.7 | 755 ± 151 | 2760 ± 780c |
| ACTH (1–39) (Ki) | 291 ± 20* | 3.95 ± 0.67c | 135 ± 22c | 2170 ± 120c | 4920 ± 610c |
| MTII (Ki) | 71.0 ± 3.3 | 0.686 ± 0.109d | 52.6 ± 7.9 | 6.60 ± 0.82f | 46.1 ± 7.9d |
| HS024 (Ki) | 72.5 ± 1.4 | 18.6 ± 3.3d | 15.1 ± 3.0 | 0.341 ± 0.089 | 3.29 ± 1.15d |
| MSH-A (Ki) | 1505 ± 262* | ||||
| MSH-B (Ki) | 352 ± 34 | ||||
| ACTH(1–31) (Ki) | 497 ± 33 |
Data taken from a [38]; b [39]; c [40]; d [41]; e [42]; f [43]