Comparison

Kisspeptin vs Melanotan I

Function

While Kisspeptin is a key regulator of the hypothalamic–pituitary–gonadal axis, controlling puberty and fertility; kisspeptin-10 also inhibits trophoblast invasion and tumor metastasis in experimental models339199, Melanotan I is approved in some regions for prevention of phototoxicity in erythropoietic protoporphyria and is studied as a skin-darkening, photoprotective peptide3444.

Mechanism

While Kisspeptin works as a family of peptides (eg, kisspeptin-10, -13, -14, -54) derived from the KISS1 precursor that activate G-protein–coupled receptor KISS1R (GPR54), triggering GnRH release and regulating pubertal onset and reproductive axis activity339199, Melanotan I is a linear 13-amino-acid analog of α-MSH (afamelanotide) that selectively activates MC1R on melanocytes, increasing eumelanin synthesis and providing photoprotection3444.

Length and Sequence

Kisspeptin is 10 amino acids long, whereas Melanotan I is longer as it has a length of 13 amino acids. Kisspeptin is made up of a sequence of Tyrosine, Asparagine, Tryptophan, Asparagine, Serine, Phenylalanine, Glycine, Leucine, Arginine, Tyrosine. Melanotan I is made up of a sequence of Serine, Tyrosine, Serine, Nle, Glutamic acid, Histidine, Phenylalanine, Arginine, Tryptophan, Glycine, Lysine, Proline, Valine.

Receptor

Kisspeptin

KISS1R (GPR54) kisspeptin receptor33919943

Melanotan I

Melanocortin-1 receptor (MC1R) 344481

Organism or Origin

Kisspeptin

Endogenous human peptide products of the KISS1 gene9199

Melanotan I

Synthetic analog of human α-MSH derived from POMC34448190

Gene

Kisspeptin

KISS1

Melanotan I

POMC

Sources

70Kisspeptin-10, rat, https://pubchem.ncbi.nlm.nih.gov/compound/Kisspeptin-10_-rat
91Kisspeptin - Wikipedia, https://en.wikipedia.org/wiki/Kisspeptin
99Kisspeptin-1 - an overview, https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/kisspeptin-1
34Melanotan I (Afamelanotide): Research Profile - PeptideJournal, https://www.peptidejournal.org/peptides/melanotan-i-research-profile
44Melanotan I: properties, applications and references, https://www.benchchem.com/zh/product/b1666627
81Proopiomelanocortin (POMC), the ACTH/melanocortin precursor, is ..., https://pmc.ncbi.nlm.nih.gov/articles/PMC2253185/
90alpha-Melanocyte stimulating hormone: production and degradation, https://pmc.ncbi.nlm.nih.gov/articles/PMC3936413/