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Melanotan-2

Melanotan-2 (MT-2, CAS 121062-08-6) is a synthetic cyclic heptapeptide lactam analog of α-melanocyte-stimulating hormone (α-MSH) with a molecular weight of approximately 1,024.2 Da. Engineered as a superpotent, broad-spectrum melanocortin receptor agonist, Melanotan-2 binds with high affinity to MC1R, MC3R, MC4R, and MC5R. It is a widely utilized research tool for studying melanocortin system biology, including melanogenesis, energy homeostasis, sexual function, and inflammation.

Technical Specifications

Property Value
CAS Number 121062-08-6
Molecular Formula C₅₀H₆₉N₁₅O₉
Molecular Weight ~1,024.2 Da
Purity ≥98% (HPLC-verified)
Appearance Lyophilized white powder
Solubility Soluble in sterile water and aqueous buffers
Storage -20°C (lyophilized), 2–8°C (reconstituted)

Mechanism of Action

Melanotan-2 is a potent, non-selective agonist at all five melanocortin receptors (MC1R–MC5R), all of which are Gαs-coupled GPCRs. At MC1R on epidermal melanocytes, it stimulates cAMP/PKA/CREB signaling, upregulating MITF and melanogenic enzymes (tyrosinase, TYRP1, DCT) to drive eumelanin synthesis and skin pigmentation. At MC4R, the predominant central melanocortin receptor expressed in the hypothalamic paraventricular nucleus (PVN), Melanotan-2 activates anorexigenic POMC/CART neurons while inhibiting orexigenic NPY/AgRP neurons, producing appetite suppression and reduced food intake. MC4R activation in the spinal cord and brainstem also modulates autonomic nervous system output, contributing to effects on erectile function through parasympathetic pathway activation. MC3R engagement influences energy partitioning and natriuresis, while MC5R activation affects exocrine gland secretion. The cyclic lactam structure (Asp²-Lys⁷) confers enhanced proteolytic stability relative to linear α-MSH while maintaining nanomolar receptor binding affinities.

Research Applications

  • Primary: Melanocortin receptor pharmacology — MC1R-mediated melanogenesis, MC4R-mediated energy homeostasis
  • Secondary: Appetite regulation and feeding behavior, melanocortin-mediated sexual function, skin pigmentation and photoprotection biology
  • Model Systems: In vitro (melanocortin receptor-transfected cell lines, primary melanocyte cultures), in vivo (feeding behavior models, skin pigmentation studies, MC4R knockout comparisons)

Quality Control & Analytical Methods

  • HPLC: ≥98% purity verification at 214/220 nm (C18 reversed-phase column)
  • Mass Spectrometry: ESI-MS for molecular weight confirmation (~1,024.2 Da)
  • Peptide Content: Amino acid analysis (AAA) for net peptide content determination
  • Endotoxin: <1 EU/mg (LAL assay)
  • TFA Content: <1% (ion chromatography)

Stability & Storage

Condition Stability
-20°C (lyophilized) 24 months
4°C (lyophilized) 6 months
25°C (lyophilized) 1 month
Reconstituted (4°C) 7 days
Reconstituted (-20°C) 30 days

Key Research References

  • Hadley & Dorr (2006) — Melanocortin peptides: melanotan-II and its derivatives. Peptides. PMID: 16558908
  • Cone (2005) — Anatomy and regulation of the central melanocortin system. Nat Neurosci. PMID: 15880099
  • Wessells et al. (1998) — Melanotan-II induces penile erections in men with erectile dysfunction. J Urol. PMID: 9723024

Source & Purchase

For researchers requiring research-grade MELANOTAN 2 with full analytical documentation including HPLC, LC-MS, and Certificate of Analysis, visit the HK Peptides product page for specifications, bulk pricing, and ordering.

View MELANOTAN 2 Product →

FAQ

Q: What purity level is standard for Melanotan-2? A: HK Peptides supplies Melanotan-2 at ≥98% purity by HPLC with full COA documentation.

Q: How should Melanotan-2 be stored for research use? A: Lyophilized Melanotan-2 should be stored at -20°C, protected from light. Reconstituted solutions at 4°C for short-term use (up to 7 days).