KPV is a three-residue peptide, lysine-proline-valine, that corresponds to the last three amino acids of alpha-melanocyte-stimulating hormone (alpha-MSH). It is a small, well-characterised molecule that has appeared in published laboratory research since the late 1980s. This article covers what KPV is, its chemical identity, the research areas in which it has been studied, and how lyophilized peptides are generally stored in the laboratory. KPV sold on this site is for laboratory research use only.
What KPV is
KPV is written in one-letter code as K-P-V and in three-letter code as Lys-Pro-Val (H-Lys-Pro-Val-OH). All three residues are standard L-amino acids, joined by two peptide bonds:
- Position 1, lysine (K): a basic residue with a primary amine on its side chain, which gives the molecule a positive charge at neutral pH.
- Position 2, proline (P): a cyclic residue that restricts the flexibility of the backbone.
- Position 3, valine (V): a branched, non-polar residue carrying the free C-terminal carboxylic acid.
Origin as an alpha-MSH fragment
Alpha-MSH is a 13-residue peptide derived from the precursor protein pro-opiomelanocortin (POMC). Its sequence ends in Gly-Lys-Pro-Val, so residues 11 to 13 are K, P and V. For this reason KPV is often called alpha-MSH(11-13) or MSH(11-13) in the literature. One structural difference is worth noting: in native alpha-MSH the C-terminal valine is amidated, while KPV as usually supplied, and as listed in PubChem, is the free acid.
Interest in the fragment goes back to work in the late 1980s, when researchers asked whether the C-terminal tripeptide alone could reproduce activity seen with the full 13-residue peptide in laboratory models (Hiltz and Lipton, 1989).
Chemical identity
| Property | Value |
|---|---|
| Sequence | Lys-Pro-Val (KPV) |
| Synonyms | alpha-MSH(11-13), MSH(11-13) |
| Molecular formula | C16H30N4O4 |
| Average molecular weight | 342.43 g/mol |
| Monoisotopic mass | 342.2267 Da |
| Expected [M+H]+ | m/z 343.234 |
| CAS number | 67727-97-3 |
| PubChem CID | 125672 |
| Typical form | Lyophilized (freeze-dried) powder |
The formula, mass and CAS number above match the PubChem record for the compound. When a mass spectrometer is used to confirm identity, the singly protonated ion near m/z 343.23 is the main value to compare against.
Research areas where KPV has been studied
Most published KPV work sits in a few research areas. All of the studies below were carried out in cell culture or in animal models, and they are summarised here by what the researchers set out to examine.
Early melanocortin fragment studies
The 1989 paper by Hiltz and Lipton tested alpha-MSH(11-13) in a mouse ear-swelling model and compared it with a corticosteroid control. The work was part of a wider research programme on which parts of the alpha-MSH sequence carry its activity in laboratory models.
Intestinal cell studies and mouse models
The most-cited KPV work comes from intestinal research:
- Dalmasso et al., 2008 (Gastroenterology; PMID: 18061177) studied how KPV enters cells. Using human intestinal epithelial cell lines (Caco2-BBE and HT29-Cl.19A) and a human T-cell line (Jurkat), the authors examined whether KPV is taken up through PepT1, a transporter for di- and tripeptides. They measured NF-kappaB reporter activity and MAP-kinase signalling in cells exposed to inflammatory cytokines, and also examined two chemically induced mouse models of the colon (DSS and TNBS).
- Kannengiesser et al., 2008 (PMID: 18092346) examined KPV in two mouse models of the colon: the DSS model and the CD45RB-high T-cell transfer model. The study also used mice with a non-functional melanocortin-1 receptor (MC1R) to ask whether the observed activity depended on that receptor. The authors reported their findings as at least partly independent of MC1R signalling.
Formulation and delivery research
Xiao et al., 2017 (PMID: 28143741) is mainly a materials-science paper. The authors loaded KPV into polymeric nanoparticles coated with hyaluronic acid, characterised the particles (an average size of about 272 nm and a slightly negative surface charge), and then examined them in a mouse model of the colon. It is a common reference for how a small, water-soluble tripeptide can be packaged in particle-based delivery systems for laboratory study.
Airway epithelial cell research
Land, 2012 used cultured human bronchial epithelial cells to study how KPV and related melanocortin peptides affect inflammatory signalling cues in that cell type. The study examined NF-kappaB pathway activity and the possible involvement of melanocortin receptors, including MC3R.
Reviews
For broader background, Brzoska et al., 2008 (Endocrine Reviews; PMID: 18612139) reviews the biochemistry of alpha-MSH and its related tripeptides, including KPV, across in vitro and in vivo laboratory studies.
Together these papers make KPV a recurring reference compound in melanocortin and peptide-transporter research. None of them establishes any use in people, and the material described here is not intended for one.
Related: see our KPV compound page for the catalogue summary.
Storage and handling of lyophilized peptides
KPV, like most research peptides, is supplied as a lyophilized powder. General laboratory practice for this kind of material:
- Long-term storage: keep sealed vials frozen, commonly at -20 C, away from light.
- Moisture: lyophilized peptides absorb water from the air. Let a cold vial come to room temperature before opening it so condensation does not form inside, and reseal it promptly.
- Light and air: store vials in their original packaging or in a dark container, and keep the headspace closed when the vial is not in use.
- Avoid repeated temperature cycling: moving a vial in and out of the freezer many times can speed up degradation, so many labs divide material into aliquots at the outset.
- Records: log the receipt date, the storage location and the laboratory ID or lot reference on the documentation, so that results can be traced back to a specific batch.
There is also a chemical reason for care with KPV in particular. Peptides with proline at the second position are known to cyclise into a diketopiperazine, and this reaction speeds up with heat and at pH far from neutral. Labs working with solutions therefore usually keep them cold and near neutral pH, and use a suitable HPLC method to check for degradation products.
Product details for the material sold on this site are on the KPV product page.
FAQ
What is KPV peptide?
KPV is the tripeptide lysine-proline-valine (Lys-Pro-Val), the C-terminal fragment (residues 11-13) of alpha-melanocyte-stimulating hormone. Its molecular formula is C16H30N4O4 and its molecular weight is 342.43 g/mol. It is supplied as a lyophilized powder for laboratory research.
Is KPV the same as alpha-MSH?
No. Alpha-MSH is a 13-residue peptide, and KPV is only its last three residues. Native alpha-MSH also has an amidated C-terminus, while KPV is usually supplied as the free acid. The two are studied separately in the research literature.
What has KPV been studied for in research?
Published studies have used KPV mainly in intestinal epithelial and immune cell lines, in mouse models of the colon, in airway epithelial cell cultures and in nanoparticle formulation work. Most of these studies looked at inflammatory signalling pathways such as NF-kappaB and at uptake through the PepT1 transporter.
How should lyophilized KPV be stored?
Common laboratory practice is to keep sealed vials frozen at around -20 C, protected from light and moisture, and to let a vial reach room temperature before opening it. Because KPV has proline at position 2, solutions are usually kept cold and near neutral pH to limit cyclisation to a diketopiperazine.
Research use only. Not for human or veterinary use. This article summarises published laboratory research for informational purposes and is not medical advice.
References
- Hiltz ME, Lipton JM. FASEB J. 1989;3(11):2282-2284. PMID: 2550304.
- Dalmasso G, Charrier-Hisamuddin L, Nguyen HT, et al. Gastroenterology. 2008;134(1):166-178. PMID: 18061177. DOI: 10.1053/j.gastro.2007.10.026
- Kannengiesser K, Maaser C, Heidemann J, et al. Inflamm Bowel Dis. 2008;14(3):324-331. PMID: 18092346.
- Xiao B, Xu Z, Viennois E, et al. Mol Ther. 2017;25(7):1628-1640. PMID: 28143741. DOI: 10.1016/j.ymthe.2016.11.020
- Land SC. Int J Physiol Pathophysiol Pharmacol. 2012;4(2):59-73. PMID: 22837805.
- Brzoska T, Luger TA, Maaser C, et al. Endocr Rev. 2008;29(5):581-602. PMID: 18612139. DOI: 10.1210/er.2007-0027
Compound data: PubChem CID 125672 (https://pubchem.ncbi.nlm.nih.gov/compound/125672).