KPV (Lys-Pro-Val) — 10 mg

A tripeptide corresponding to the C-terminal fragment of α-MSH, studied in in-vitro models of inflammatory regulation and epithelial function. 10 mg vial, lyophilized powder, ≥99% HPLC purity verified by third-party analysis. For laboratory research use only.

Research areas

• In-vitro inflammatory models
• Melanocortin signalling
• Epithelial barrier (models)

Technical data

KPV or α-MSH: why the tripeptide alone is studied

α-MSH is a 13-amino-acid peptide cleaved from pro-opiomelanocortin. Its last three C-terminal residues — lysine, proline, valine — are KPV. The product name is literally the sequence.

The confusion the market keeps alive comes from that lineage: a hormone fragment is casually presented as "a version of the hormone", and assumed to reproduce its effects. That is not what the literature describes. Whole α-MSH binds the MC1R-MC5R melanocortin receptors with high affinity — receptors involved in pigmentation and appetite regulation. The tripeptide is not described as reproducing that binding: published work presents it as retaining the anti-inflammatory side of the parent sequence while shedding the pigmentary and metabolic effects of the whole hormone. This dissociation is what makes the fragment worth studying.

The criterion that settles it is checkable on a COA and purely a matter of mass: ≈ 342.4 Da over 3 residues for KPV, against ≈ 1,665 Da over 13 residues for α-MSH. A vial sold as "KPV" whose mass spectrum peaks near 1,665 Da does not contain the tripeptide. It follows that KPV does not belong with the compounds studied for skin pigmentation — mistaking it for a melanotropic analogue is the most common identification error on this reference.

Mechanism studied

Mechanistic work converges on intracellular inflammatory signalling. KPV is studied as an inhibitor of the NF-κB pathway, interfering upstream at IκB kinase activation, with reduced nuclear translocation of NF-κB reported in some cell models. Several studies also describe modulation of the MAPK pathways and a decrease in reactive oxygen species, translating in vitro into lower production of TNF-α, IL-1β and IL-6.

A third strand concerns transport: in intestinal epithelium, KPV is described as taken up by PepT1, a di- and tripeptide transporter. That route follows directly from the compound's size — PepT1 does not carry long peptides — and it underpins the intestinal-inflammation literature.

What the literature shows

Two publications anchor the field. Dalmasso et al. (Gastroenterology, 2008) described PepT1-mediated uptake of KPV together with reduced intestinal inflammation across cultured epithelial and immune cells and animal models. Kannengiesser et al. (Inflammatory Bowel Diseases, 2008) reported anti-inflammatory potential of the tripeptide in murine models of inflammatory bowel disease. Beyond those, three strands structure the corpus: intestinal inflammation, the best documented; skin, with re-epithelialisation and keratinocyte-migration models; and general inflammation, with exploratory work on neuroprotection and antimicrobial activity.

What the literature does not show matters just as much. This is preclinical evidence, from cell culture and rodents: no established human clinical trial validates therapeutic efficacy, and translation to humans is not demonstrated. Bioavailability, stability and pharmacokinetics remain partly characterised, heterogeneous models and the absence of standardisation limit generalisation, and the human safety profile is not documented in any regulatory framework.

Reconstitution: a worked example

With 2 mL of bacteriostatic water in a 10 mg vial: 10 mg ÷ 2 mL = 5 mg/mL, i.e. 5,000 mcg/mL. On a U-100 syringe, 10 IU = 0.1 mL = 500 mcg, giving 20 draws per vial.

The most common trap: the volume of water never changes how much peptide is in the vial. Reconstituting with 1 mL gives 10 mg/mL — the same total mass in half the volume. Only the volume to draw changes. Our reconstitution calculator computes any other combination live.

Add the solvent slowly down the vial wall, then swirl gently. No vigorous shaking, no vortex — shear denatures peptides.

Storage

Lyophilized powder: -20 °C or below, protected from light and moisture; stable for years when unopened. After reconstitution: 2–8 °C, protected from light, with a reference shelf life of 28 days. For longer storage, frozen aliquots are preferable to repeated freeze-thaw cycles.

Common laboratory mistakes

• Expecting α-MSH effects from KPV. The fragment is not described as binding melanocortin receptors with high affinity: no pigmentation, no appetite effect in published models.
• Treating published concentrations as a dose. Micromolar culture concentrations and rodent doses are protocol-specific and do not transpose.
• Using plain sterile water for a multi-draw vial. Without a preservative, the solution is no longer protected once the stopper has been pierced several times.
• Vortexing the vial. Vigorous agitation denatures peptides.
• Repeatedly refreezing the reconstituted solution. Each cycle degrades a fraction of the tripeptide.