Chemical Specifications and Research Applications of KPV Peptide (CAS 67727-97-3)

What is the KPV Peptide CAS Number?

The primary CAS Registry Number for the KPV peptide (sequence Lysine-Proline-Valine) is 67727-97-3. This unique chemical identifier designates the free-base tripeptide sequence H-Lys-Pro-Val-OH. When supplied as a salt formulation for laboratory research, such as KPV acetate, derivative CAS numbers or specific lot registries may apply, but 67727-97-3 remains the definitive global standard for the primary amino acid chain.

Establishing the correct CAS registry designation ensures that biomedical investigators, procurement officers, and analytical chemists can correctly reference material safety data sheets (MSDS), verify chemical identity across international reference databases, and differentiate high-purity synthesized peptides from non-standardized chemical mixtures. For precise experimental reproducibility in preclinical models, researchers must confirm that candidate lots correspond strictly to CAS 67727-97-3.

Chemical Structure, Molecular Weight, and Physical Properties

Chemically, KPV is a tripeptide composed of the amino acids L-lysine, L-proline, and L-valine linked via standard peptide bonds. Its systematic IUPAC name is (S)-2-((S)-1-((S)-2,6-diaminohexanoyl)pyrrolidine-2-carboxamido)-3-methylbutanoic acid. The chemical formula for the free peptide is C16H30N4O4, yielding a monoisotopic molecular mass of 342.23 Da and a average molecular weight of approximately 342.43 g/mol.

Because of its short chain length, KPV exhibits distinct physicochemical advantages over larger parent molecules such as α-MSH. The tripeptide possesses enhanced thermal and enzymatic stability, reduced susceptibility to proteolytic cleavage, and high solubility in aqueous buffer systems. Synthesized via solid-phase peptide synthesis (SPPS), high-purity KPV tripeptide is typically isolated as a white to off-white lyophilized powder requiring controlled storage parameters to preserve its structural integrity.

Preclinical Anti-Inflammatory Mechanisms of Action

In preclinical laboratory investigations, KPV has demonstrated robust anti-inflammatory properties that operate independently of full-length melanocortin receptor activation. Unlike full-length α-MSH, which binds broadly to MC1R through MC5R to induce systemic signaling and melanogenesis, KPV acts primarily through cellular uptake via peptide transporters and direct intracellular pathway modulation.

In vitro studies demonstrate that KPV enters intestinal epithelial cells and immune cells via the solute carrier transporter PEPT1 (SLC15A1). Once internalized, KPV translocates into the cytoplasm and cell nucleus, where it directly interacts with the p65 subunit of nuclear factor kappa B (NF-κB). By inhibiting p65 nuclear translocation and blocking NF-κB-dependent transcriptional activation, KPV downregulates the expression of key pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6).

KPV in Intestinal Barrier and Colitis Research Models

The primary focus of contemporary KPV literature centers on mucosal immunology, intestinal barrier function, and experimental inflammatory bowel disease (IBD) models. In animal models of colitis—such as dextran sulfate sodium (DSS)-induced or trinitrobenzene sulfonic acid (TNBS)-induced colitis—administration of KPV in controlled laboratory settings has been shown to attenuate histological mucosal damage, reduce leukocyte infiltration, and diminish colonic tissue myeloperoxidase (MPO) activity.

In vitro cell culture assays using Caco-2 and HT-29 intestinal epithelial monolayers further demonstrate that KPV preserves tight junction integrity during inflammatory challenge. Exposure to pro-inflammatory signaling typically degrades tight junction proteins such as zonula occludens-1 (ZO-1) and occludin, leading to hyperpermeability. Preclinical data show that treatment with KPV mitigates this degradation, maintaining transepithelial electrical resistance (TEER) and preventing pathological mucosal permeability.

Comparative Analysis: KPV vs. Related Inflammatory and Mucosal Peptides

When designing preclinical assays targeting mucosal repair or inflammatory cascade suppression, researchers routinely evaluate KPV against other prominent candidates within the research peptide catalog. Each compound targets distinct biochemical receptors and intracellular cascades, offering specialized utility across different experimental setups.

In mucosal barrier and anti-inflammatory research, investigators frequently compare KPV against other synthetic and endogenously derived research peptides. While KPV tripeptide functions primarily through intracellular PEPT1-mediated NF-κB suppression, BPC-157 operates through angiogenic growth factor modulation and focal adhesion kinase activation to promote tissue repair in connective and gastric tissue models. Similarly, larazotide acetate targets tight junction assembly directly through zonulin receptor antagonism, and LL-37 provides direct antimicrobial defenses alongside immunomodulatory signaling. Reviewing these compounds across the broader PX1 Research catalog enables laboratories to select optimal candidate molecules for specific comparative protocols.

Quality Verification Standards for Laboratory-Grade KPV

Maintaining rigorous experimental reproducibility requires sourcing research peptides that adhere to strict chemical purity criteria. Uncertified or low-grade peptides frequently contain synthesis truncated sequences, residual trifluoroacetic acid (TFA), organic solvents, or heavy metals that distort cell culture assays and generate false-positive anti-inflammatory observations.

At PX1 Research, every lot of KPV (CAS 67727-97-3) undergoes comprehensive analytical verification to guarantee identity, purity, and safety. Manufactured under cGMP-compliant conditions within US-based facilities, all lots are subjected to independent third-party testing at ISO 17025 accredited analytical laboratories. Principal analytical documentation—including lot-specific Certificates of Analysis (COAs)—is made readily accessible to research institutions to verify chemical compliance prior to experimental deployment.

Analytical Purity Assessment: RP-HPLC, Mass Spectrometry, and Endotoxin Testing

Definitive verification of KPV relies on a multi-tiered analytical testing battery to establish structural fidelity and freedom from biologically active contaminants:

1. Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC): Chromatographic separation is conducted using C18 stationary phase columns with acetonitrile/water gradient elution containing 0.1% TFA. UV detection at 214 nm confirms a single major peak corresponding to ≥98% chromatographic purity, verifying the absence of truncated peptide impurities or side-products.

2. Electrospray Ionization Mass Spectrometry (ESI-MS): Mass spectroscopic analysis confirms the exact molecular weight of the parent ion ([M+H]+ at m/z ~343.24), verifying that the sequence corresponds strictly to Lys-Pro-Val without unwanted adducts, oxidation, or sequence inversion.

3. Bacterial Endotoxin Quantification: Because lipopolysaccharides (LPS) directly trigger NF-κB activation and pro-inflammatory cytokine expression in cell culture models, endotoxin contamination destroys the validity of anti-inflammatory research. PX1 Research subjects all peptide lots to Chromogenic Limulus Amebocyte Lysate (LAL) testing, enforcing stringent endotoxin limits (<0.01 EU/mg) to ensure clean background signaling in sensitive in vitro protocols.

Laboratory Handling, Reconstitution, and Storage Protocols

Lyophilized KPV peptide (CAS 67727-97-3) is stable at room temperature for brief periods during transit, but long-term storage requires dedicated cold-chain management. Upon receipt in the laboratory, unopened vials of lyophilized powder should be stored at -20°C or -80°C in a desiccated environment to prevent moisture absorption and peptide hydrolytic degradation.

For reconstitution, researchers should allow the vial to equilibrate to ambient room temperature before opening to minimize condensation formation. Reconstitute using sterile, endotoxin-free bacteriostatic water, sterile normal saline, or phosphate-buffered saline (PBS, pH 7.4) depending on the intended assay environment. Once reconstituted, stock solutions should be divided into single-use laboratory aliquots and stored at -80°C to avoid repeated freeze-thaw cycles, which cause structural degradation. Reconstituted aqueous solutions stored at 2°C to 8°C should be utilized within 7 to 14 days. Note: All handling protocols apply strictly to in vitro and preclinical laboratory research.

Sourcing Verified Research Peptides from PX1 Research

PX1 Research serves as a trusted primary supply partner for academic institutions, biotechnology companies, and contract research organizations (CROs) requiring verified, high-purity research compounds. By maintaining centralized fulfillment hubs in California and Arizona, PX1 Research provides same-day dispatch for qualified institutional orders, minimizing supply chain lead times for active research projects.

Principal investigators and laboratory managers requiring high-volume reagents can explore customized procurement contracts through our wholesale laboratory accounts. Furthermore, researchers seeking detailed molecular background data, stability studies, and published peer-reviewed references can access our comprehensive technical library available within the PX1 Research Hub.