Kisspeptin-10 (KP-10) is a synthetic decapeptide (sequence Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Phe-NH₂), the shortest active fragment of kisspeptin that fully retains its receptor activity. It corresponds to region 45–54 of metastin (or 112–121 of the full KISS1 protein) and carries a C-terminal amide group (-NH₂) that is critical for activity. Despite its small size, KP-10 binds the receptor even more tightly than full-length metastin — roughly 8-fold.
Mechanism of Action
KP-10 is a potent agonist of the KISS1R receptor (also called GPR54), a Gq-coupled receptor on hypothalamic neurons. By activating them, it triggers pulsatile release of gonadotropin-releasing hormone (GnRH), which drives the pituitary to secrete luteinizing (LH) and follicle-stimulating (FSH) hormones, and those in turn drive sex-hormone production (testosterone, estradiol). Kisspeptin–KISS1R signaling is the central trigger node of the whole hypothalamic-pituitary-gonadal (HPG) axis: it initiates puberty, coordinates ovulation and maintains fertility. It acts fast but briefly (short half-life), so in research it is often given by infusion or repeated boluses. Separately, kisspeptin acts as a metastasis suppressor (inhibiting chemotaxis, tumor-cell invasion and VEGF) and influences osteoblast differentiation (via the GPR54 → NFATc4 → BMP2/Runx2 cascade).
Effects in Research
KP-10 is one of the most widely used tools in reproductive endocrinology. In men, an intravenous KP-10 bolus rapidly raises LH and its pulse frequency (George et al., 2011); it is studied in delayed puberty, hypogonadotropic hypogonadism, ovulation disorders and infertility, and as a "gentle" trigger of egg maturation in IVF with a lower risk of ovarian hyperstimulation syndrome (OHSS). Beyond reproduction, kisspeptin enhances emotional and sexual processing in limbic brain regions (hence interest in libido and attraction), is studied in oncology (suppression of melanoma and breast-cancer metastasis), in bone metabolism (osteogenesis), and as a marker of pre-eclampsia. GnRH/kisspeptin analogues are on the WADA prohibited list.
Properties
White to off-white lyophilized powder, readily soluble in water (including bacteriostatic). A decapeptide with a C-terminal amide group. Formula C₆₃H₈₃N₁₇O₁₄, molecular weight ≈1302.5 Da. CAS 374675-21-5, PubChem CID 25240297. Synonyms: KP-10, Metastin (45-54), KiSS-1 (112-121), Kisspeptin-10 (human).
Storage
Store the lyophilized powder at 2–8°C in a dry place protected from light; for long-term storage −20°C is optimal. After reconstitution keep refrigerated, do not freeze, and use within a few weeks.
BIOLABCHEMICALS