KPV is the tripeptide Lys-Pro-Val, the last three amino acids of alpha-melanocyte-stimulating hormone (alpha-MSH). It is small, hydrophilic and positively charged, and it is studied in cell and animal models of inflammation, mainly in the gut, skin and airway. Its one built-in chemical weakness is the proline in second position, which lets its first two residues close into a ring.
This reference collects what a laboratory needs to know about KPV as a material: how its three residues behave 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 | KPV (L-lysyl-L-prolyl-L-valine) |
|---|---|
| Also known as | alpha-MSH (11-13), Lys-Pro-Val |
| Sequence | Lys-Pro-Val (KPV) |
| Residues | 3 |
| Molecular formula | C16H30N4O4 |
| Molecular weight | 342.43 g/mol |
| CAS number | 67727-97-3 |
Formula, molecular weight, CAS number and synonyms are from PubChem (CID 125672), and the same figures appear in the specifications on our KPV 10 mg product page. PubChem’s synonyms for that record include “free acid”. Our product page gives the formula and CAS number but does not use the words free acid or amide, so we do not label the vial either way here. Amide versions exist in the literature (Songok et al., PLoS One, 2018).
Three features of that sequence explain most of its behaviour. It is too small and too plain for most degradation routes: there is no methionine, cysteine, tryptophan, histidine or tyrosine to oxidise, and no asparagine, glutamine or aspartic acid to deamidate or isomerise. Its proline sits at position 2, the arrangement that allows a peptide to cut itself by closing a diketopiperazine ring, and stress testing of KPV found exactly that ring as the major degradation product (Pawar et al., Biomedical Chromatography, 2015). And with a lysine side chain and a free N-terminal amine, it carries a net positive charge in near-neutral solution, which makes it very soluble in water.
What it is studied for
Most KPV work concerns inflammation in cells and rodents. In human intestinal epithelial cells and T cells, nanomolar KPV inhibited NF-kappaB and MAP kinase signalling and reduced pro-inflammatory cytokine secretion. It entered those cells through PepT1, the di- and tripeptide transporter, and it reduced inflammation in two mouse colitis models (Dalmasso et al., Gastroenterology, 2008). A second group found similar effects in two mouse colitis models, including mice with a nonfunctional melanocortin-1 receptor, so the effect appears at least partly independent of that receptor (Kannengiesser et al., Inflammatory Bowel Diseases, 2008).
That fits the mechanism work. In a mouse peritonitis model KPV reduced white cell accumulation but, unlike alpha-MSH, did not raise cAMP in macrophages, and the authors concluded it is unlikely to act through melanocortin receptors (Getting et al., Journal of Pharmacology and Experimental Therapeutics, 2003). In immortalised human bronchial epithelial cells, KPV suppressed NF-kappaB signalling and IL-8 and eotaxin secretion, an effect linked to blocked nuclear import of the p65RelA subunit (Land, International Journal of Physiology, Pathophysiology and Pharmacology, 2012).
Other lines include a rabbit cornea wound model, where KPV sped up re-epithelialisation in a way that appeared to involve nitric oxide (Bonfiglio et al., Experimental Eye Research, 2006), and bacterial work, where alpha-MSH fragments including KPV killed Staphylococcus aureus in culture (Singh and Mukhopadhyay, Antimicrobial Agents and Chemotherapy, 2011). A later group saw no antimicrobial activity for an acetylated amide form (Songok et al., PLoS One, 2018). No human study of KPV was identified. Our summaries are in KPV: the anti-inflammatory tripeptide, explained and how KPV comes from alpha-MSH.
Stability
With three residues and nothing to oxidise or deamidate, KPV has one main chemical route: closing a diketopiperazine ring from Lys-Pro, which heat speeds up strongly. The KPV stability page covers those routes, freeze-thaw, light and what visible changes mean.
Solubility
KPV has a computed XLogP of minus 3.5 and a net positive charge near neutral pH, so it dissolves in bacteriostatic water straight away and needs no acid. The KPV solubility guide explains why, which concentrations dissolve cleanly and what causes haze.
Handling
Bench practice for KPV is mostly about keeping the solution cold, clean and labelled. The KPV 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 it and the ready-mixed spray go first are on the KPV on-arrival page.
Storage and reconstitution
Fridge and freezer windows, before and after mixing, are on how long KPV lasts. Water volumes and the concentration table for a 10 mg vial are on how much bacteriostatic water for a KPV 10 mg vial.
FAQ
Short answers to the questions researchers ask most about storing, mixing and handling KPV are on the KPV FAQ.
Where to get it
Vistara Labs supplies KPV 10 mg as a lyophilised vial for laboratory research, shipped within Canada by Canada Post Xpresspost. A ready-mixed KPV Nasal Spray is also available, in two bottle sizes. KPV is one of the four components of the KLOW blend, covered in its own research reference. Certificates are on our lab reports page.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
