Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide widely investigated in preclinical models for its regulatory roles in neuroimmunology, vascular tone, and anti-inflammatory signaling pathways. PX1 Research supplies research-grade lyophilized VIP manufactured in the USA under strict analytical standards. Every lot is verified via RP-HPLC, mass spectrometry, and endotoxin assays to ensure maximum reproducibility in benchtop and in vitro experimental designs.
Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide widely investigated in preclinical models for its regulatory roles in neuroimmunology, vascular tone, and anti-inflammatory signaling pathways. PX1 Research supplies research-grade lyophilized VIP manufactured in the USA under strict analytical standards. Every lot is verified via RP-HPLC, mass spectrometry, and endotoxin assays to ensure maximum reproducibility in benchtop and in vitro experimental designs.
When principal investigators and laboratory specialists seek to buy VIP peptide, obtaining verifiable purity and batch consistency is critical. Vasoactive Intestinal Peptide (VIP) is supplied strictly as a research-grade compound for in-vitro and laboratory investigation. It is not intended for human consumption, clinical diagnostic procedures, or therapeutic administration.
PX1 Research provides high-purity VIP peptide synthesized in USA-based facilities operating under strict Quality Management Systems. Each lot undergoes comprehensive third-party testing at an ISO 17025 accredited laboratory, confirming peptide sequence purity over 98% via Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) and verifying exact molecular weight through Electrospray Ionization Mass Spectrometry (ESI-MS). Real-time lot documentation and Certificates of Analysis (COAs) are accessible for every order.
Vasoactive Intestinal Peptide is a basic, single-chain 28-amino acid peptide belonging to the glucagon/secretin superfamily of regulatory peptides. Its primary sequence (His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn-NH2) features a C-terminal alpha-amidated residue critical for binding affinity and biological activity in cell-culture assays.
In preclinical structural analyses, VIP exhibits a random coil structure in aqueous solution but transitions into an alpha-helical conformation upon interaction with phospholipid membranes or specific receptor domains. Research indicates that the N-terminal sequence primarily mediates receptor activation, whereas the central and C-terminal regions dictate high-affinity binding to G-protein coupled receptors (GPCRs).
In vitro assays demonstrate that VIP functions primarily through two high-affinity class B G-protein coupled receptors: VPAC1 (expressed predominantly in cerebral cortex, liver, gut epithelium, and T-lymphocytes) and VPAC2 (expressed in the central nervous system, smooth muscle cells, and endocrine pancreas).
Upon receptor ligation, VIP stimulates membrane-bound adenylyl cyclase, driving rapid intracellular increases in cyclic adenosine monophosphate (cAMP). This cascade downstream activates Protein Kinase A (PKA) and Epac pathways, leading to phosphorylation of transcription factors such as CREB. Preclinical studies suggest these signaling cascades regulate pro-inflammatory gene transcription, macrophage polarization, and neuroprotective protein expression.
VIP has gained broad interest across immunologic research due to its capacity to modulate innate and adaptive immune responses in cellular and animal models. In activated macrophage assays, exposure to VIP leads to the inhibition of nuclear factor kappa B (NF-κB) translocation, subsequently downregulating pro-inflammatory cytokines such as TNF-α, IL-6, IL-12, and IFN-γ.
Simultaneously, in vitro data indicate that VIP promotes the expression of anti-inflammatory mediators, including IL-10 and TGF-β. In dendritic cell cultures, VIP treatment induces a tolerogenic phenotype characterized by reduced co-stimulatory molecule expression (CD80, CD86, CD40), steering naive T-cell differentiation toward regulatory T-cell (Treg) populations. Researchers interested in broader immunomodulatory cascades can explore related targets within our comprehensive research library.
Within neurobiology models, VIP demonstrates significant trophic and protective influences on neuronal populations. Rodent primary co-cultures exposed to excitotoxic insult or lipopolysaccharide (LPS)-induced neuroinflammation display elevated survival rates when pre-incubated with synthetic VIP.
Mechanistic investigations reveal that VIP activates microglial VPAC1 receptors, inhibiting microglial activation and the subsequent release of neurotoxic reactive oxygen species (ROS) and nitric oxide (NO). Additionally, VIP stimulates astrocytic release of neurotrophic factors, including activity-dependent neuroprotective protein (ADNP), positioning this peptide as a benchmark reference standard in neuroimmunology experimental protocols.
Laboratory researchers evaluating peptide mediators of inflammation frequently compare VIP against structural homologues and alternative immunomodulatory agents. Understanding these comparative profiles aids in selecting the optimal reagent for specific cell-line assays:
VIP shares significant structural homology with PACAP-38 research peptides, binding VPAC1 and VPAC2 with equal nanomolar affinity. However, PACAP-38 exhibits distinct affinity for the dedicated PAC1 receptor, making VIP the preferred candidate when isolating VPAC-selective intracellular signaling pathways. In contrast, tripeptide sequences like KPV peptide operate through alpha-MSH receptor mechanisms, while antimicrobial peptides such as LL-37 peptide alter membrane permeability and bind formyl peptide receptors. Selecting among these compounds depends heavily on whether the research framework targets GPCR-mediated cAMP cascades or direct membrane interactions.
To preserve structural integrity and prevent degradation of the C-terminal amide, proper handling protocols must be maintained upon receipt of lyophilized VIP peptide:
1. **Centrifugation:** Always brief-centrifuge the vial prior to opening to consolidate the lyophilized cake at the bottom of the container. 2. **Solubilization:** Reconstitute using sterile target-grade water (Bacteriostatic Water or Sterile Water for Injection) or phosphate-buffered saline (PBS, pH 7.4). For assays sensitive to residual benzyl alcohol, sterile 0.9% sodium chloride or pure sterile water is recommended. 3. **Solubility Optimization:** VIP dissolves readily in aqueous buffer solutions up to concentrations of 1–2 mg/mL. Gentle agitation or inversion is sufficient; avoid aggressive vortexing to prevent shear-induced aggregation. 4. **Storage Parameters:** Store the dry lyophilized powder at -20°C or -80°C upon arrival. Once reconstituted, aliquot the solution into single-use polypropylene tubes to minimize freeze-thaw cycles and store at -80°C. Aliquots remain stable for short-term benchwork at 4°C for up to 48 hours. Review our detailed peptide reconstitution guide for precise concentration mathematical models.
Inconsistent peptide purity or undetected bacterial endotoxins introduce severe confounding variables in cell culture and preclinical assays. Low-grade peptides contaminated with lipopolysaccharides can trigger non-specific inflammatory responses, masking the natural anti-inflammatory activity of VIP.
At PX1 Research, every batch of VIP undergoes rigorous dual-analytical validation. RP-HPLC chromatograms confirm chromatographic purity exceeding 98.0%, ensuring the absence of truncated sequences or oxidation artifacts (such as methionine sulfoxide variants). Electrospray mass spectrometry verifies exact mass identity against calculated molecular weight (3325.8 Da). Furthermore, chromogenic LAL assays ensure endotoxin levels remain below strict threshold limits (<0.01 EU/mg), guaranteeing clean, predictable baseline responses in sensitive cell assays. Learn more about our testing standards on our storage and stability guide.
PX1 Research operates dedicated manufacturing and distribution channels originating entirely within the United States, utilizing shipping nodes in California and Arizona to guarantee rapid delivery across domestic and international research facilities. Same-day dispatch is standard for orders placed before cut-off times Monday through Friday.
We serve academic universities, biotechnology organizations, contract research organizations (CROs), and independent research laboratories requiring transparent supply chains. Laboratories seeking recurring bulk volumes or custom synthesis options can submit requests directly through our wholesale account portal to access tiered institutional pricing and dedicated account oversight.
What is Vasoactive Intestinal Peptide (VIP) used for in research?
VIP is supplied exclusively as a research-grade chemical compound for in vitro and preclinical laboratory research. It is studied for its interactions with VPAC1 and VPAC2 receptors, anti-inflammatory cytokine modulation, immune cell signaling pathways, and neuroprotective dynamics in cellular models.
How can I verify the purity of VIP peptide from PX1 Research?
Every lot of VIP peptide includes a lot-specific Certificate of Analysis (COA). Purity is quantitatively verified via RP-HPLC (>98%), mass identity is confirmed through ESI-MS mass spectrometry, and biological safety is checked with quantitative LAL endotoxin testing.
What solvent should be used to reconstitute lyophilized VIP?
Lyophilized VIP is readily soluble in sterile water for injection, 0.9% sterile saline, or phosphate-buffered saline (PBS, pH 7.4). Avoid high-shear mechanical agitation during reconstitution to preserve peptide secondary structure.
What are the recommended storage conditions for VIP?
Desiccated lyophilized powder should be stored at -20°C or -80°C for long-term stability. Following reconstitution, aliquot the peptide into single-use microcentrifuge vials and freeze at -80°C to prevent degradation from repeated freeze-thaw cycles.
How does VIP differ from PACAP-38 in receptor selectivity?
While both belong to the glucagon/secretin peptide superfamily and bind VPAC1 and VPAC2 receptors with comparable high affinity, PACAP-38 also binds the PAC1 receptor with high affinity. VIP lacks significant affinity for PAC1, making it a valuable tool to isolate VPAC-specific signaling.
What is the molecular weight and chemical formula of VIP?
Vasoactive Intestinal Peptide (human/bovine/porcine sequence) has a molecular weight of approximately 3325.8 Da and a chemical formula of C147H238N44O42S.
Where is PX1 Research VIP peptide manufactured and shipped from?
All PX1 Research compounds are manufactured in USA-based, GMP-compliant facilities and shipped directly from fulfillment centers in California and Arizona with same-day shipping available Monday through Friday.
Can academic institutions order VIP peptide in bulk?
Yes, PX1 Research provides institutional sourcing and volume discounts for university labs, CROs, and corporate research teams via our dedicated wholesale program.
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.