KPV Molecular Weight, Sequence & CAS Reference
KPV is a C-terminal tripeptide fragment derived from alpha-melanocyte-stimulating hormone (alpha-MSH) that serves as a primary subject in preclinical inflammatory pathway research. This technical reference manual provides validated physical specifications, including the exact KPV molecular weight sequence parameters, CAS identifier, chemical structure, salt counterion impact, and analytical handling guidelines for laboratory settings. All data herein is intended strictly for qualified researchers evaluating in vitro and preclinical experimental models.
Quick answer
KPV is a C-terminal tripeptide fragment derived from alpha-melanocyte-stimulating hormone (alpha-MSH) that serves as a primary subject in preclinical inflammatory pathway research. This technical reference manual provides validated physical specifications, including the exact KPV molecular weight sequence parameters, CAS identifier, chemical structure, salt counterion impact, and analytical handling guidelines for laboratory settings. All data herein is intended strictly for qualified researchers evaluating in vitro and preclinical experimental models.
Key takeaways
- [KPV](/research-peptides/kpv) is a naturally occurring tripeptide consisting of three amino acids linked via peptide bonds: L-lysine, L-proline, and L-valine.
- The primary amino acid sequence of [KPV](/research-peptides/kpv) is Lysine-Proline-Valine.
- Precise stoichiometry requires exact values for molecular weight and chemical formula.
- Solid-phase peptide synthesis (SPPS) typically utilizes trifluoroacetic acid (TFA) during the final cleavage and deprotection steps.
Chemical Overview and Structural Identity of KPV
KPV is a naturally occurring tripeptide consisting of three amino acids linked via peptide bonds: L-lysine, L-proline, and L-valine. Synthesized naturally as the carboxy-terminal tripeptide sequence of alpha-melanocyte-stimulating hormone (α-MSH), KPV retains significant biological signaling activity while exhibiting a dramatically simplified molecular structure. In laboratory literature, researchers often classify KPV as a targeted anti-inflammatory research peptide due to its observed capacity to modulate nuclear factor kappa B (NF-κB) and downstream cytokine cascades without eliciting classical melanocortin receptor-mediated pigmentary effects.
When sourcing reagents for molecular biochemistry, structural clarity is paramount. The tripeptide structure allows for distinct physicochemical properties, high solubility in aqueous buffer systems, and enhanced stability relative to full-length neuropeptides. PX1 Research supplies high-purity KPV 10mg vials synthesized under strict laboratory controls to ensure reproducible baseline characteristics across all experimental replicates. Researchers examining mucosal immunity, epithelial permeability, or cellular transport mechanisms rely on exact chemical profiling to configure quantitative assays.
Amino Acid Sequence and Molecular Architecture
The primary amino acid sequence of KPV is Lysine-Proline-Valine. In standard single-letter amino acid code, it is represented simply as KPV, while three-letter notation designates it as H-Lys-Pro-Val-OH. The N-terminus features an unblocked alpha-amino group on the lysine residue, whereas the C-terminus contains a free carboxyl group on the valine residue, unless specific research designs specify terminal modifications such as N-acetylation or C-amidation.
The molecular architecture of KPV is characterized by the rigid pyrrolidine ring of the central proline residue. Proline introduces a conformational constraint into the peptide backbone, forcing a fixed bend or turn that is critical for receptor binding interactions and enzymatic resistance in cell culture media. Surrounding proline are the basic, positively charged side chain of lysine (ε-amino group) at the N-terminus and the hydrophobic, branched side chain of valine at the C-terminus. This amphipathic structure enables KPV to interact dynamically with lipid membranes and intracellular target proteins during in vitro signaling studies.
Molecular Weight, Formula, and CAS Registry Numbers
Precise stoichiometry requires exact values for molecular weight and chemical formula. The neutral (free base) molecular formula for KPV is C16H30N4O4. Based on standard IUPAC atomic weights, the monoisotopic mass is calculated at 342.2267 Da, with a average molecular weight of approximately 342.43 g/mol. When calculating molarities for cell culture media or analytical solutions, researchers must utilize the chemical weight of the specific salt form supplied.
The Chemical Abstracts Service (CAS) registry number assigned to the free base form of KPV is 67727-92-6. In academic literature, related salt forms or derivatives (such as Ac-KPV or specific stereoisomeric forms) may possess distinct CAS registry entries. When referencing chemical databases or cross-referencing published literature, confirming both the structural formula and the exact CAS entry ensures accurate documentation. At PX1 Research, every batch listed in our research peptide directory is cross-verified against verified mass spectra to guarantee formula integrity.
Peptide Salt Forms: TFA vs. Acetate Counterions and Net Content
Solid-phase peptide synthesis (SPPS) typically utilizes trifluoroacetic acid (TFA) during the final cleavage and deprotection steps. Consequently, crude and HPLC-purified peptides initially exist as TFA salts. Because the lysine residue in KPV contains a basic side chain and a free N-terminus, a single KPV molecule can associate with up to two TFA counterion molecules (CF3COOH). The presence of TFA counterions increases the gross molecular weight of the raw powder.
To illustrate the impact on assay preparation: free base KPV has a formula weight of 342.43 g/mol. If paired with two TFA counterions (molecular weight ~114.02 g/mol each), the combined salt formula weight rises to approximately 570.47 g/mol. In this state, the 'net peptide content' (the percentage of actual KPV peptide by mass relative to total mass including counterions and residual moisture) may range between 60% and 75%. Alternatively, acetate counterion exchange yields KPV acetate, which replaces TFA with acetic acid molecules (CH3COOH, ~60.05 g/mol), altering the net peptide content accordingly. Researchers must check the batch-specific Certificate of Analysis (COA) to account for net peptide content when calculating exact micromolar concentrations.
Preclinical Research Focus: Intestinal Barrier and Inflammatory Pathways
In preclinical literature, KPV is primarily investigated for its capacity to attenuate acute and chronic inflammatory signaling. A substantial body of in vitro and animal model research focuses on its transport across intestinal epithelial cells via the peptide transporter 1 (PepT1). Studies in human intestinal epithelial cell lines (such as Caco-2 and HT-29) demonstrate that PepT1 facilitates intracellular uptake of KPV, where the tripeptide directly interacts with signaling cascades.
Once internalized, preclinical data suggest KPV inhibits the translocation of the NF-κB p65 subunit into the nucleus, thereby downregulating the transcription of pro-inflammatory cytokines including IL-6, IL-1β, and TNF-α. In murine models of experimental colitis (e.g., dextran sulfate sodium-induced colitis), oral or systemic administration of KPV research preparations demonstrated reductions in mucosal inflammation, preserved tight junction protein expressions (ZO-1 and Occludin), and accelerated histological recovery. These findings make KPV a valuable tool for investigating mucosal immunology and barrier restoration mechanisms in controlled laboratory settings.
Comparative Class Analysis: KPV vs. Alpha-MSH and Related Mucosal Peptides
To understand KPV's unique profile, it is helpful to contrast it with full-length neuropeptides and alternative mucosal research compounds. While parent peptide alpha-MSH binds broadly to melanocortin receptors (MC1R through MC5R) to influence pigmentation and metabolic pathways, KPV lacks the central His-Phe-Arg-Trp pharmacophore required for classical melanocortin receptor activation. Instead, KPV exerts anti-inflammatory actions independently of classic MC1R signaling, reducing systemic side-effect variables in cell culture models.
When comparing KPV to other gut-barrier research peptides, researchers frequently analyze BPC-157 5mg and larazotide. While BPC-157 is studied primarily for its angiogenic and extracellular matrix remodeling properties, and larazotide acts as a tight junction receptor antagonist blocking zonulin pathways, KPV offers a distinct mechanism centered on PepT1-mediated intracellular transport and direct nuclear NF-κB inhibition. Evaluating these complementary mechanisms allows investigators to map distinct stages of inflammatory cascade resolution.
Analytical Verification: HPLC, Mass Spectrometry, and Endotoxin Standards
Given that trace impurities can confound cell culture assays or in vivo inflammatory readouts, chemical purity must be rigorously verified before experimental deployment. High-Performance Liquid Chromatography (HPLC) is utilized to measure chemical purity, verifying that the main KPV peak constitutes ≥98% of total integrated UV absorbance. Electrospray Ionization Mass Spectrometry (ESI-MS) confirms the exact molecular mass by detecting the protonated molecular ion ([M+H]+ = 343.24 m/z).
For cell-based and animal research models, endotoxin contamination presents a critical confounding variable, as bacterial lipopolysaccharides (LPS) trigger the exact NF-κB pathway KPV is used to study. PX1 Research enforces stringent quality control across all batches, subjecting every lot to chromogenic Limulus Amebocyte Lysate (LAL) endotoxin testing. Our peptides are manufactured in ISO 17025 accredited and GMP-compliant facilities within the USA, ensuring that lot-specific COAs confirm negligible endotoxin levels prior to dispatch.
Laboratory Reconstitution, Handling, and Storage Protocols
Lyophilized KPV powder exhibits high stability when stored at -20°C or -80°C in a desiccated environment away from light. Prior to opening the vial, researchers should allow the container to equilibrate to room temperature to prevent condensation of atmospheric moisture onto the cake. Reconstitution should be performed using sterile, bacteriostatic or deionized water, or phosphate-buffered saline (PBS, pH 7.4).
To determine accurate liquid volumes based on molarity or mass target, investigators can utilize the PX1 Reconstitution Calculator. Once dissolved, aqueous KPV solutions should be aliquoted into single-use polypropylene tubes to prevent repeated freeze-thaw cycles, which can induce peptide degradation. Reconstituted aliquots remain stable at 4°C for short-term experimentation (1–2 weeks) or at -80°C for long-term storage up to 6 months. Reagents should always be handled under sterile laminar flow hoods using chemical-resistant laboratory safety equipment.
PX1 Research Quality Standards & Supply Chain Integrity
PX1 Research serves as a premier USA-based supplier dedicated exclusively to laboratory research applications. Every product offered across our catalog, from specialized tripeptides to broad neuropeptide libraries, undergoes rigorous independent quality control. We mandate third-party HPLC and MS testing for every single production lot, publishing verified results openly for institutional review.
Operating out of fulfillment facilities in California and Arizona, PX1 Research provides same-day dispatch for orders placed Monday through Friday before 3:00 PM PST. Whether conducting exploratory in vitro screens or large-scale preclinical trials, research institutions can rely on our transparent manufacturing, rapid fulfillment, and specialized wholesale lab accounts for consistent, high-purity research compounds.
Frequently Asked Questions
What is the exact molecular weight and sequence of KPV?
KPV has the amino acid sequence Lysine-Proline-Valine (Lys-Pro-Val). Its neutral molecular formula is C16H30N4O4, corresponding to a monoisotopic mass of 342.23 Da and an average molecular weight of approximately 342.43 g/mol.
What is the CAS registry number for KPV?
The CAS registry number for KPV free base is 67727-92-6. Salt forms, such as KPV acetate or KPV TFA, may possess distinct CAS entries or be cataloged under the parent molecule ID in scientific literature.
How does TFA salt content affect net peptide calculations?
Trifluoroacetic acid (TFA) counterions associate with basic amino acid residues (like Lysine) during synthesis. TFA adds non-peptide mass to the overall lyophilized weight. Researchers must consult the lot-specific Certificate of Analysis to identify the net peptide content (typically 60-80%) when calculating exact molar concentrations.
Through what mechanism does KPV interact with cells in preclinical studies?
Preclinical data show that KPV is actively transported into intestinal epithelial cells via the PepT1 transporter. Inside the cell, it inhibits the translocation of the NF-κB p65 subunit, thereby suppressing pro-inflammatory cytokine expression.
Can KPV be used for human administration or therapeutic trials?
No. KPV provided by PX1 Research is strictly sold as a research chemical for in vitro, cell culture, and laboratory animal research. It is not licensed, labeled, or intended for human or veterinary medical use, clinical diagnosis, or therapeutic treatment.
How should reconstituted KPV solutions be stored in the laboratory?
Reconstituted KPV solutions should be divided into single-use aliquots to avoid freeze-thaw damage. Short-term storage (up to two weeks) is suitable at 4°C, while long-term storage requires -80°C.
What analytical tests are performed on PX1 Research KPV batches?
Each batch of KPV undergoes High-Performance Liquid Chromatography (HPLC) to verify purity (≥98%), Electrospray Ionization Mass Spectrometry (ESI-MS) to verify molecular mass, and LAL testing to confirm low endotoxin levels.
Where does PX1 Research manufacture and ship its peptide products?
All PX1 Research compounds are manufactured in USA-based, GMP-compliant facilities. Orders are fulfilled from centralized research distribution hubs in California and Arizona, offering same-day dispatch Monday through Friday.
Related pages
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.