Melanin biosynthetic pathway

Melanin biosynthesis is a multi-step metabolic pathway responsible for the production of melanin pigments, including *eumelanin* (brown-black pigment) and *pheomelanin* (red-yellow pigment)[2][1][4][3]. The process initiates with the amino acid tyrosine, converted to dopaquinone by the enzyme tyrosinase (the rate-limiting and essential enzyme)[2][1][6]. Additional enzymes, such as tyrosinase-related proteins (TYRP1, TYRP2), further process intermediates, resulting in distinct melanin types[1][3]. The pathway is tightly regulated by various factors, including the melanocortin 1 receptor (MC1R), which controls the switch between pheomelanin and eumelanin synthesis via signaling molecules like α-MSH and ACTH[3][4]. Defects in the enzymes or regulatory proteins involved in melanin biosynthesis are associated with pigmentation disorders (e.g., albinism, vitiligo, melasma)[2][1][4]. Some therapeutic approaches target key enzymes or signaling proteins in this pathway to modulate skin pigmentation in medical and cosmetic contexts. Note: *Melanin biosynthesis* is a biological process—not a single molecule, canonical target, receptor, enzyme, or transporter. For structured drug target databases, the relevant entries include the enzymes (e.g., tyrosinase) or receptors (e.g., MC1R) involved in the pathway rather than the process itself.

Other names

Melanin synthesisMelanogenesisEumelanin biosynthesisMelanin formation

Inhibition of tyrosinase activity (e.g., hydroquinone, kojic acid) Modulation of melanocortin signaling (e.g., afamelanotide acts as a MC1R agonist stimulating melanin synthesis) Antioxidant/photoprotection through increased melanin production