KPV 10mg

KPV is a tripeptide consisting of the three amino acids lysine, proline, and valine — Lys-Pro-Val. It is the C-terminal tripeptide of the larger neuropeptide α-melanocyte-stimulating hormone (α-MSH), a 13-residue peptide that signals through the melanocortin receptor family (MC1R through MC5R) and that plays roles in pigmentation, energy homeostasis, sexual function, and inflammation. KPV came to research attention in the 1990s and 2000s through a series of studies — particularly the work of Anna Catania, James Lipton, and colleagues — that characterized the tripeptide as retaining substantial anti-inflammatory activity despite lacking the residues required for activation of the classical melanocortin receptors.

The interest in KPV is rooted in this dissociation between melanocortin-receptor signaling and anti-inflammatory activity. The full α-MSH peptide has well-characterized anti-inflammatory effects in multiple animal-model systems, but it also has potent effects on melanocortin receptors that mediate other biological functions (pigmentation through MC1R, food intake and energy balance through MC4R, etc.). KPV — lacking the MSH "core" sequence (His-Phe-Arg-Trp) required for melanocortin-receptor activation — appears in the published research literature to retain meaningful anti-inflammatory activity through mechanisms that do not depend on the classical melanocortin receptors, making it of interest as a tool for characterizing the anti-inflammatory biology of the α-MSH system separately from the pigmentation, appetite, and other receptor-mediated effects.

This page is an educational reference for readers who want a careful, plain-English explanation of what KPV actually is, where it sits in the larger α-MSH and melanocortin-research story, what the published research describes about its proposed mechanisms in inflammation and mucosal biology, and where it fits in the broader landscape of small-peptide research compounds. It is not a medical guide, does not describe any therapy or anti-inflammatory protocol, and makes no claims about effects in people who acquire the compound for research purposes. KPV supplied as a research peptide is intended for laboratory and analytical work only.

KPV is the simplest of small linear tripeptides: three amino acids — L-lysine, L-proline, L-valine — joined by two peptide bonds. The molecular formula is C16H31N5O4 (free acid form), with a molecular weight of approximately 357.4 daltons. The peptide has no covalent modifications beyond the standard amide-bond backbone, no disulfide bonds (there are no cysteines), no D-amino acids, no cyclization, and is in the all-L-amino-acid configuration corresponding to the C-terminal residues of natural α-MSH. The sequence is short enough that the molecule is effectively a small drug-like compound in terms of physicochemical properties, rather than a peptide of the size that would behave biophysically like a larger neuropeptide.

The amino acid composition gives the peptide a single basic residue (the lysine, which carries a positive charge at physiological pH from its side-chain amine), no acidic residues, and one constrained residue (the proline, which restricts backbone conformation). The N-terminal lysine and the C-terminal valine carboxylate provide the standard zwitterionic free-acid form; the C-terminus may also be supplied as the amide (KPV-NH2) in some research-peptide preparations, which more closely mimics the in-context C-terminal amide of the parent α-MSH peptide. The choice of free-acid versus amide form is an important detail to confirm against the Certificate of Analysis for any specific research lot.

The peptide is derived conceptually from α-MSH (the 13-residue sequence Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2), where KPV constitutes the C-terminal three residues (positions 11-13 of α-MSH). The proposed mechanism for KPV's anti-inflammatory activity does not depend on the His-Phe-Arg-Trp "MSH core" sequence (positions 6-9 of α-MSH) that is required for activation of MC1R through MC5R. Various proposals in the literature have implicated direct intracellular effects on signaling pathways — including effects on NF-κB signaling, on mast-cell stabilization, on cytokine production by various immune cell types, and on epithelial-barrier function in mucosal contexts — that appear in the published research to operate independently of the classical melanocortin receptors.

It is worth being specific about what KPV is not. It is not a melanocortin-receptor agonist of any of the five classical melanocortin receptors — the absence of the MSH core sequence precludes meaningful activation at those targets. It is not a pigmentation peptide — it has no characterized direct effects on melanin synthesis. It is not α-MSH — although it is derived from the parent peptide, the two have substantially different biological profiles. And it is not an approved medicine in any major international regulatory jurisdiction; the research-peptide form is supplied for laboratory and analytical use only.

The history of KPV is part of the broader history of α-MSH research and the gradual recognition that the anti-inflammatory activity of α-MSH is at least partly dissociable from the receptor-mediated effects that define the classical melanocortin pharmacology.

α-MSH itself was first characterized in the 1950s as part of the broader characterization of the pro-opiomelanocortin (POMC) precursor system. The 13-residue α-MSH structure was established, and the molecule was characterized for its pigmentation effects (acting on dermal melanocytes through what would later be identified as MC1R) and for its various central nervous system effects (acting on hypothalamic MC4R and on other melanocortin receptors). The anti-inflammatory effects of α-MSH were characterized in subsequent decades in multiple animal-model contexts, including endotoxin-induced fever, various models of acute inflammation, and broader characterizations of the molecule's effects on cytokine production and on inflammatory-cell function.

Through the 1980s and 1990s, the question of which parts of the α-MSH molecule were responsible for which functional effects became an active area of structure-activity research. The MSH "core" sequence (His-Phe-Arg-Trp, positions 6-9) was established as the minimal sequence required for binding and activation of the melanocortin receptors. Various N-terminal and C-terminal fragments were characterized for residual biological activity. The C-terminal tripeptide KPV (and the C-terminal tetrapeptide GKPV) emerged in this work as α-MSH fragments that retained meaningful anti-inflammatory activity in published animal-model studies despite the loss of melanocortin-receptor activation.

The systematic characterization of KPV's anti-inflammatory effects was advanced particularly by Anna Catania and James Lipton and colleagues through a series of publications beginning in the 1990s. Their work characterized KPV's effects in multiple models of inflammation — acute endotoxin challenge, various models of skin inflammation, contact-hypersensitivity models, and others — and developed the hypothesis that the C-terminal anti-inflammatory activity operates through mechanisms distinct from those of the classical melanocortin-receptor-mediated effects of α-MSH.

In the 2000s and 2010s, research interest in KPV expanded into mucosal and intestinal contexts. Particularly notable was a series of studies by Didier Merlin and colleagues at Emory University characterizing KPV's effects in models of intestinal inflammation, including dextran-sulfate-sodium and trinitrobenzenesulfonic-acid models of colitis. These studies characterized the peptide's effects on epithelial-barrier function, on mucosal cytokine production, on intestinal inflammation in various contexts, and on the integration of these effects with the broader mucosal-immunology landscape. Other groups have studied KPV in the context of mast-cell biology, where the peptide has been characterized as a mast-cell stabilizer in some experimental contexts.

The continuing KPV research in the 2020s spans intestinal and mucosal-inflammation models, dermal-inflammation models, characterization of the specific cellular and molecular mechanisms behind the proposed anti-inflammatory effects, and continuing structure-activity exploration of related small α-MSH-derived peptides. The published research literature on KPV is more modest in volume than that of many of the better-known peptides discussed elsewhere in this catalog, but the focused mechanistic interest in the dissociation between anti-inflammatory and melanocortin-receptor effects has kept the peptide as an active research subject.

The science of KPV centers on three connected areas: the structural relationship to α-MSH and the receptor-independent mechanism hypothesis, the characterized anti-inflammatory effects across multiple model systems, and the specific cellular and molecular mechanisms that have been proposed in the published literature.

• Linear tripeptide of three residues (Lys-Pro-Val), MW approximately 357.4 Da.
• C-terminal tripeptide of the parent α-MSH 13-residue neuropeptide; lacks the MSH 'core' required for melanocortin-receptor activation.
• Characterized in published research as anti-inflammatory through proposed mechanisms independent of MC1R-MC5R signaling.
• Active research context in mucosal-inflammation and intestinal-barrier biology, particularly through the Merlin group's published work.
• Specific molecular target(s) responsible for the anti-inflammatory activity have not been definitively identified.

Structurally, KPV is the simplest of small linear tripeptides — three amino acids (L-lysine, L-proline, L-valine) joined by two peptide bonds. The molecular formula is C16H31N5O4 for the free-acid form, with a molecular weight of approximately 357.4 daltons. The amide form (KPV-NH2), which more closely corresponds to the C-terminus of natural α-MSH, has the formula C16H32N6O3 with a molecular weight of approximately 356.5 daltons.

The amino acid composition gives the peptide a single basic side chain (the lysine ε-amine, which carries a positive charge at physiological pH), no acidic side chains, and one conformationally constrained residue (the proline). The N-terminal amine and the C-terminal carboxylate (in the free-acid form) provide additional charged groups. The overall molecule is relatively hydrophilic and water-soluble, with limited but non-zero hydrophobic character contributed by the valine side chain and by the proline ring.

The peptide has no aromatic residues — KPV does not contain any tryptophan, tyrosine, or phenylalanine — so the molecule has minimal UV absorbance at the standard 280 nm wavelength used for peptide concentration determination. Concentration determination for KPV preparations typically requires alternative approaches such as quantitative amino acid analysis or mass-based weighing.

The molecular size — approximately 357 daltons, with only three amino acids — places KPV at the boundary between "peptide" and "small molecule" in terms of physicochemical behavior. The molecule is small enough to potentially access drug-like pharmacokinetic behavior, though the standard peptide-bond chemistry remains susceptible to proteolytic degradation by gastric and tissue proteases.

KPV is studied across laboratory contexts in inflammation biology and mucosal research.

In intestinal-inflammation models, KPV is used in animal-model studies of colitis (typically the dextran-sulfate-sodium and trinitrobenzenesulfonic-acid models) to characterize effects on histological inflammation, on mucosal cytokine production, on epithelial-barrier function, and on broader integration with the mucosal-immunology landscape. The intestinal-research context, particularly developed by Didier Merlin's group and others, has been one of the most active sub-areas of contemporary KPV research and has framed continuing interest in the peptide as a tool for characterizing inflammatory-bowel-disease-related biology.

In mast-cell research, KPV is used in characterization of mast-cell-stabilizing effects in various experimental contexts. The mast-cell research applications include in-vitro characterization of histamine and other mediator release, in-vivo models of mast-cell-driven inflammation (allergic-airway models, urticaria models), and broader characterization of the peptide's effects on mast-cell biology.

In skin and dermal-inflammation research, KPV is used in characterization of effects in contact-hypersensitivity models and in other dermal-inflammation paradigms. The skin-research applications connect to the broader α-MSH-derived-peptide anti-inflammatory literature that has been particularly developed in the dermatology-research context.

In broader inflammation-biology research, KPV serves as a tool for characterizing the dissociation between melanocortin-receptor-mediated effects of α-MSH (pigmentation, appetite, sexual function) and the anti-inflammatory effects that appear to operate through different mechanisms. The peptide's role as a probe for these mechanism-dissociation questions is one of its more distinctive uses in the broader α-MSH research landscape.

In epithelial-barrier research, KPV has been characterized for effects on tight-junction proteins, on transepithelial electrical resistance in in-vitro epithelial-monolayer systems, and on broader integration with the epithelial-barrier biology that has emerged as a major focus of mucosal-immunology research.

Across all of these contexts, the research applications are laboratory and analytical in nature. The research-peptide supply of KPV is intended for laboratory work only and does not include any clinical, therapeutic, or anti-inflammatory-treatment context.

KPV sits within a family of α-MSH-derived research peptides and within the broader landscape of small peptides studied for anti-inflammatory and mucosal-research effects.

KPV is a tripeptide consisting of L-lysine, L-proline, and L-valine — the C-terminal three residues of the 13-residue parent neuropeptide α-melanocyte-stimulating hormone (α-MSH). The molecular weight is approximately 357 daltons, making KPV one of the smallest peptides in the research-peptide landscape and placing it at the boundary between peptide and small-molecule physicochemical behavior.

The published KPV research literature characterizes the peptide's anti-inflammatory activity across multiple animal-model systems — intestinal-inflammation models (DSS and TNBS colitis), dermal-inflammation models, mast-cell-mediated inflammation models, and broader characterizations of effects on cytokine production and inflammation-related signaling. The central mechanistic hypothesis is that KPV retains meaningful anti-inflammatory activity through mechanisms independent of the classical melanocortin receptors (MC1R through MC5R), activation of which requires the MSH core sequence (His-Phe-Arg-Trp) absent from the C-terminal KPV tripeptide. Proposed downstream mechanisms include effects on NF-κB signaling, mast-cell stabilization, and epithelial-barrier function in mucosal contexts, though the specific proximal molecular target(s) responsible for these effects remain one of the open questions of the field.

The mucosal- and intestinal-research context, particularly through the work of Didier Merlin's group at Emory University, has been one of the most actively developed sub-areas of contemporary KPV research and has framed continuing interest in the peptide as a tool for characterizing inflammatory-bowel-disease-related biology in animal-model and preclinical contexts.

KPV is not approved as a medicine in major international regulatory jurisdictions. The research-peptide form is supplied for laboratory and analytical use only, and educational discussion should remain within that framing rather than drift into therapeutic claims about anti-inflammatory treatment.

For students, researchers, and curious readers approaching KPV for the first time, the most accurate framing is of a small α-MSH-derived tripeptide whose research interest stems from the dissociation between melanocortin-receptor-mediated effects of the parent α-MSH (pigmentation, appetite, sexual function) and the C-terminal anti-inflammatory effects that operate through different (and still incompletely characterized) mechanisms, with an active research program centered on intestinal and mucosal inflammation models.