MT2

Overview

Melanotan II (MT2) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH) developed at the University of Arizona. It is a non-selective agonist of melanocortin receptors MC1R through MC5R. MT2 was originally designed as a potential photoprotective agent through its ability to stimulate melanogenesis. Its broad melanocortin receptor binding profile has made it a widely used research tool for studying the melanocortin system, one of the most diverse neuropeptide signalling systems in vertebrate biology.

Mechanism of Action

MT2 binds to melanocortin receptors, with particular affinity for MC1R (melanogenesis), MC3R, MC4R (energy homeostasis and appetite), and MC5R (exocrine function). At MC1R on melanocytes, it activates the cAMP-PKA-CREB pathway, upregulating MITF (microphthalmia-associated transcription factor) which drives expression of tyrosinase and other melanogenic enzymes. This cascade converts L-tyrosine to eumelanin, the brown-black photoprotective pigment. The cyclic structure of MT2 confers greater enzymatic stability and receptor binding affinity compared to the linear α-MSH sequence.

Research Applications

• Melanogenesis and pigmentation biology research
• Melanocortin receptor selectivity and signalling studies
• UV photoprotection mechanism investigation
• MC3R/MC4R energy homeostasis pathway research
• Neuropeptide structure-activity relationship studies