KPV: Research Compound Profile

KPV is a synthetic tripeptide catalogued as a laboratory research reference material. This profile summarises its verified chemical identity, physical description, and the analytical methods used to confirm identity and estimate purity per batch. It is written for documentation purposes only and makes no claims about outcomes.

Compound identity

KPV is the three-letter designation for the peptide Lys-Pro-Val (single-letter code K-P-V). It corresponds to residues 11 to 13 of alpha-α-MSH (alpha-MSH), the C-terminal fragment of that sequence, which is why the compound is also indexed in chemical databases as MSH(11-13). Its registry identifiers are stable and cross-referenceable:

• Compound name: KPV (Lys-Pro-Val tripeptide)
• CAS number: 67727-97-3
• PubChem CID: 125672
• Molecular formula: C₁₆H₃₀N₄O₄
• Average molecular weight: 342.43 g/mol (monoisotopic 342.23)
• IUPAC name: (2S)-2-[[(2S)-1-[(2S)-2,6-diaminohexanoyl]pyrrolidine-2-carbonyl]amino]-3-methylbutanoic acid

The molecular weight above is consistent with a residue calculation: the free amino acids lysine (146.19), proline (115.13) and valine (117.15) sum to 378.47, and forming two peptide bonds removes two water molecules (36.03), giving 342.44 g/mol. This agrees with the PubChem record for CID 125672.

Structure and appearance

KPV is a linear tripeptide built from three L-amino acid residues joined by two amide bonds. The N-terminus carries the lysine side-chain amine, proline contributes its characteristic pyrrolidine ring at the central position, and the C-terminus is the free carboxylic acid of valine. As a short, unmodified peptide it presents as a white to off-white lyophilised powder. The lysine side chain makes the molecule water-soluble, so solution preparation for analytical work is typically carried out with sterile water; short peptides of this class are generally kept frozen and protected from repeated freezing and thawing to preserve sample integrity during handling.

Identity and purity testing

Because KPV is a small, defined sequence, its identity can be confirmed unambiguously by mass spectrometry. The three standard analytical checks applied to a batch are:

• LC-MS / HRMS (identity): liquid chromatography coupled to mass spectrometry confirms the intact mass. The expected protonated ion [M+H]⁺ for C₁₆H₃₀N₄O₄ is approximately m/z 343.23. High-resolution mass spectrometry (HRMS) narrows the measured mass to a few parts per million, distinguishing the correct sequence from close-mass impurities.
• HPLC (purity): reversed-phase high-performance liquid chromatography separates the target peptide from truncation or deletion sequences and process residues. Purity is reported as the target peak area as a percentage of total peak area. The separation performance of the column determines how well minor related peaks are resolved.
• Sequence confirmation: MS/MS fragmentation, or comparison against a characterised reference, verifies the residue order Lys-Pro-Val rather than an isomeric arrangement.

How to read a Certificate of Analysis

A Certificate of Analysis (COA) is the primary record that ties a physical vial to its measured chemistry. When reviewing a COA for a compound like KPV, the fields worth checking are the batch or lot number, the stated identity method (LC-MS or HRMS) with the observed mass, the purity method (HPLC) with the reported percentage, the appearance description, and the date and laboratory that performed the analysis. A complete COA lets a record be reproduced and audited independently.

Livvmore batch testing

Every livvmore reference batch is identity- and purity-tested by mass spectrometry at the USC Alfred E. Mann Multi-Omics Mass Spectrometry Core, a university laboratory, and the resulting certificates are published rather than held on request. For KPV, batch B10001 was analysed at that facility and returned an estimated purity of approximately 99.1%, with the intact mass confirming the Lys-Pro-Val identity. The full document is available in the COA library, and the batch-specific certificate is linked from the KPV product record.

Research context

In the published scientific literature, the isolated KPV tripeptide is catalogued as the C-terminal motif of alpha-MSH (residues 11 to 13) and is indexed under this identity on PubChem and referenced in peptide-chemistry reviews on PMC. These citations are provided here as bibliographic background on where the sequence sits in the peptide literature; they describe the cataloguing and study of the molecule as a chemical entity and are not statements about any product.

For laboratory research use only. Not for human or veterinary use.

Frequently asked questions

What is the amino acid sequence of KPV?

KPV is the tripeptide Lys-Pro-Val (single-letter code K-P-V). It consists of an L-lysine residue at the N-terminus, a central L-proline, and an L-valine residue with a free carboxylic acid at the C-terminus, joined by two peptide bonds. The sequence corresponds to residues 11 to 13 of alpha-α-MSH.

What is the molecular weight and formula of KPV?

KPV has the molecular formula C16H30N4O4 and an average molecular weight of 342.43 g/mol (monoisotopic mass 342.23). These values are recorded under PubChem CID 125672 and CAS number 67727-97-3, and they are consistent with a residue-based calculation from lysine, proline and valine.

What is the CAS number for KPV?

The CAS Registry Number for the KPV tripeptide (Lys-Pro-Val) is 67727-97-3. It is also indexed in PubChem as CID 125672 and under the synonym MSH(11-13), reflecting its origin as the C-terminal fragment of alpha-MSH.

How is the identity of a KPV batch confirmed?

Identity is confirmed by liquid chromatography coupled to mass spectrometry (LC-MS) or high-resolution mass spectrometry (HRMS), which verifies the intact mass; the expected protonated ion for C16H30N4O4 is about m/z 343.23. Purity is estimated separately by reversed-phase HPLC, reported as the target peak area percentage. Livvmore batch B10001 was tested at the USC Alfred E. Mann Multi-Omics Mass Spectrometry Core at approximately the estimated purity recorded on its Certificate of Analysis.

What does KPV look like as a research material?

KPV is supplied as a white to off-white lyophilised (freeze-dried) powder. As a short peptide bearing a lysine side chain it is water-soluble, and samples are generally kept frozen and protected from repeated freezing and thawing to preserve integrity during laboratory handling.