Binding and cAMP studies of melanotropin peptides with the cloned human peripheral melanocortin receptor, hMC1R.
Haskell-Luevano. C C; Miwa. H H; Dickinson. C C; Hruby. V J VJ; Yamada. T T; Gantz. I I
Key Findings
- Alpha‑MSH binds MC1R with an IC50 of ~6.5 nM and activates cAMP with an EC50 of ~2 nM.
- MT‑I is ~5‑fold more potent than alpha‑MSH (IC50 ~1.2 nM, EC50 ~0.5 nM).
- MT‑II is ~10‑fold more potent than alpha‑MSH (IC50 ~0.57 nM, EC50 ~0.20 nM).
Practical Outcomes
- For biohackers using melanotan peptides for tanning, the data suggest you can achieve the same receptor activation with much lower doses of MT‑I or MT‑II compared to natural alpha‑MSH. Start with the lowest effective dose to minimize side effects, but note the study does not address broader health or performance effects.
Summary
This study measured how strongly the skin‑pigment hormone alpha‑MSH and its stronger lab‑made versions (MT‑I and MT‑II) stick to and activate the human MC1R receptor, which controls melanin production. The results show that the synthetic peptides bind and trigger the receptor at much lower concentrations than the natural hormone, confirming they are far more potent.
Abstract
Binding and stimulation of cAMP by the melanotropin peptides alpha-MSH (alpha-melanocyte-stimulating hormone) and its superpotent analogues [Nle4, DPhe7]alpha-MSH (MT-I) and Ac-[Nle4,[formula: see text]alpha-MSH4-10-NH2 (MT-II) were undertaken to examine their respective properties on the human peripheral melanocyte melanocortin receptor, hMC1R. alpha-MSH was found to possess a binding IC50 value of 6.5 +/- 0.9 x 10(-9) M and cAMP EC50 value of 2.0 +/- 0.6 x 10(-9) M. MT-I possesses a binding IC50 value of 1.2 +/- 0.3 x 10(-9) M and a cAMP EC50 of 0.5 +/- 0.03 x 10(-9) M. MT-II possesses a binding IC50 of 0.57 +/- 0.08 x 10(-9) M and cAMP EC50 value of 0.20 +/- 0.05 x 10(-9) M.
Study Information
pubmed
1994
1994-11-15T00:00:00.000Z
10.1006/bbrc.1994.2581