Kisspeptin: Research Reference

Kisspeptin-10 is a synthetic ten-residue peptide, Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Phe-NH2, the C-terminal end of the 54-residue hormone kisspeptin, also called metastin. It is the shortest form of the hormone that keeps its activity at the kisspeptin receptor, and it is the form our kisspeptin vials and spray contain.

This reference collects what a laboratory needs to know about kisspeptin-10 as a material: how its sequence behaves in the vial, what it dissolves in, how it is handled at the bench and what to do when an order arrives. Each section below has its own page.

Molecular reference

Name	Kisspeptin-10
Also known as	Metastin 45-54, KP-10, human kisspeptin-10
Sequence	Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Phe-NH2 (YNWNSFGLRF-NH2; C-terminal amide)
Residues	10 (positions 45 to 54 of kisspeptin-54)
Molecular formula	C63H83N17O14
Molecular weight	1302.4 g/mol
CAS number	374675-21-5

Formula, molecular weight, CAS number, synonyms and the sequence are from PubChem (CID 25240297).

Three features of that sequence explain most of its behaviour. It has two asparagines, at positions 2 and 4, the residue that deamidates in solution through a ring intermediate (Geiger and Clarke, Journal of Biological Chemistry, 1987). It has four aromatic residues, a tyrosine, a tryptophan and two phenylalanines, and tryptophan and tyrosine are among the residues most open to oxidation, which light can drive (Li et al., Biotechnology and Bioengineering, 1995). And it has no methionine or cysteine, with a C-terminal amide rather than a free acid, so some common weak points are absent. Light, warmth and time are therefore the things to manage once it is mixed.

What it is studied for

The parent peptide was isolated from human placenta in 2001 as the natural ligand of an orphan G-protein-coupled receptor, now called KISS1R, and named metastin because it reduced cell invasion and metastasis in laboratory models (Ohtaki et al., Nature, 2001). It is now best known as a regulator of the reproductive axis, acting upstream of gonadotropin-releasing hormone. Kisspeptin-10 has three to ten times higher receptor affinity than the full peptide but is rapidly inactivated in serum, and analogues with a substitute for its tryptophan were far more stable in mouse serum (Asami et al., Bioorganic and Medicinal Chemistry Letters, 2012).

Human studies are physiological research in small groups of healthy volunteers. In men, kisspeptin-10 produced a rapid rise in luteinising hormone and increased its pulse frequency (George et al., Journal of Clinical Endocrinology and Metabolism, 2011). In women the response depended on the phase of the menstrual cycle, with no change in the follicular phase and a rise in the preovulatory phase (Jayasena et al., Journal of Clinical Endocrinology and Metabolism, 2011). A direct comparison in men found kisspeptin-10 and kisspeptin-54 had similar effects on gonadotropin secretion and both were less potent than GnRH (Jayasena et al., Human Reproduction, 2015).

As context for how short-lived it is in the body: the plasma half-life of the longer kisspeptin-54 in men was 27.6 minutes (Dhillo et al., Journal of Clinical Endocrinology and Metabolism, 2005), and in rat plasma kisspeptin-10 broke down with a half-life of minutes, losing its first tyrosine (Liu et al., Journal of Chromatography B, 2013). Those figures measure enzymes in blood, not a sterile vial. Our summaries are in what is kisspeptin, kisspeptin vs HCG and PT-141 vs kisspeptin.

Stability

Kisspeptin-10 has more weak points than most peptides in this series: two asparagines that can deamidate and four aromatic residues, including an oxidation-prone tryptophan. The kisspeptin stability page works through each residue, along with light, freeze-thaw and what visible changes mean.

Solubility

Kisspeptin-10 carries two positive charges at the pH of bacteriostatic water and dissolves in it without acid, though its aromatic residues make gentle technique more important. The kisspeptin solubility guide explains why and what causes haze.

Handling

Bench practice for kisspeptin-10 is mostly about keeping the solution cold, dark, sterile and labelled. The kisspeptin handling page lists the steps and the common mistakes.

On arrival

What a sealed vial should look like, why it travels without an ice pack and where the vial and the spray go first are on the kisspeptin on-arrival page.

Storage and reconstitution

Fridge and freezer windows, before and after mixing, are on how long kisspeptin lasts. Water volumes and the concentration table for a 10 mg vial are on how much bacteriostatic water for a kisspeptin 10 mg vial.

FAQ

Short answers to the questions researchers ask most about storing, mixing and handling kisspeptin-10 are on the kisspeptin FAQ.

Where to get it

Vistara Labs supplies Kisspeptin 10 mg as a lyophilised vial for laboratory research, shipped within Canada by Canada Post Xpresspost. A ready-mixed Kisspeptin Nasal Spray is also available. Certificates are on our lab reports page.