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, Semax is used clinically in Russia for ischemic stroke and cognitive disorders; in models it improves learning, protects dopaminergic neurons, and modulates stress responses without significant endocrine ACTH-like effects166174.
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, Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP), that is an analog of ACTH(4–10) with a Pro-Gly-Pro extension and exerts neurotrophic and neuroprotective actions partly via upregulation of BDNF and modulation of dopaminergic and glutamatergic systems40162165174.
Length and Sequence
Kisspeptin is 10 amino acids long, whereas Semax is shorter as it has a length of 7 amino acids. Kisspeptin is made up of a sequence of Tyrosine, Asparagine, Tryptophan, Asparagine, Serine, Phenylalanine, Glycine, Leucine, Arginine, Tyrosine. Semax is made up of a sequence of Methionine, Glutamic acid, Histidine, Phenylalanine, Proline, Glycine, Proline.