Kisspeptin-10

Chemical identity

Kisspeptin-10 is the shortest fragment of the KISS1 gene product that retains full activity at its receptor. The parent protein is processed in vivo into peptides of 54, 14, 13 and 10 residues; all share the C-terminal RFamide motif, and all bind KISS1R with comparable affinity.

The C-terminal amidation is essential. The free-acid form is dramatically less active, which makes amidation confirmation a real specification point — and one that a nominal-mass measurement can miss, since the difference is a single dalton.

Mechanism in research models

KISS1R is a Gq-coupled receptor whose activation drives phospholipase C, inositol trisphosphate generation and intracellular calcium mobilisation. In the hypothalamus, kisspeptin neurons in the arcuate and anteroventral periventricular nuclei sit directly upstream of GnRH neurons.

This places kisspeptin at the top of the reproductive axis. Its discovery reframed how the field understood the onset of puberty: loss-of-function mutations in KISS1R produce hypogonadotropic hypogonadism, and the peptide is now the standard tool for probing GnRH pulse generation in animal models.

The arcuate kisspeptin population co-expresses neurokinin B and dynorphin — the so-called KNDy neurons — and this circuit is the current best model for the GnRH pulse generator itself. Experiments using kisspeptin as a probe should be designed with that co-expression in mind.

What the literature establishes

The neuroendocrine role is among the better-established findings in modern reproductive biology, supported by human genetics, rodent knockout work and controlled human physiology studies. This is not a compound with a thin evidence base.

Research has extended into metabolic regulation, where kisspeptin signalling appears to link energy status to reproductive capacity, and into oncology, where KISS1 was originally identified as a metastasis-suppressor gene — the source of the name metastin.

Half-life in circulation is short. Studies requiring sustained receptor occupancy generally use infusion rather than bolus designs, and protocols transplanted from longer-lived peptides will not translate.

Handling, reconstitution and storage

Lyophilised material is typically held sealed and desiccated at −20 °C or colder; the validated condition is the one on the lot documentation. Kisspeptin-10 contains tryptophan, which is photolabile — amber vials and light-protected storage are not optional for this sequence.

The peptide is soluble in water and in dilute aqueous buffer. Where solubility is slow, a small volume of dilute acetic acid will assist, but confirm buffer compatibility with your assay first rather than after.

Aliquot on reconstitution. Solutions are noticeably less stable than the lyophilised powder, and the tryptophan and methionine-free sequence still oxidises at the indole ring on standing.

Analytical documentation

Require RP-HPLC purity, an observed mass matching the amidated sequence, and net peptide content. Ask specifically whether the certificate confirms C-terminal amidation — with a one-dalton difference from the free acid, low-resolution MS will not resolve it and the free acid is the common synthesis failure.

Tryptophan-containing peptides show characteristic UV absorbance at 280 nm, which gives a convenient orthogonal concentration check against the gravimetric label if your laboratory has a spectrophotometer.

References and authoritative sources

Chemical identity, regulatory status and anti-doping classification should be confirmed against primary sources rather than against this page. The records below are the ones to check first.

1. PubChem compound record (US National Library of Medicine)
2. PubMed indexed literature
3. UniProt protein record

These are database and regulatory sources. Citations to specific primary papers are being added to this page as part of ongoing scientific review; until they appear, treat the mechanism and literature sections above as a summary to verify rather than a citation of record.