Product details
VIP (Vasoactive Intestinal Peptide) is a 28-amino-acid neuropeptide and member of the secretin/glucagon peptide superfamily, originally isolated from porcine duodenum but later found to be widely distributed in the central and peripheral nervous systems. The molecule signals through two G-protein-coupled receptors (VPAC1 and VPAC2) and produces a remarkably broad pharmacological profile: vasodilation, bronchodilation, suppression of pro-inflammatory cytokine production by macrophages and T-cells, modulation of circadian rhythms in the suprachiasmatic nucleus, and effects on gut motility and exocrine secretion. The breadth of VIP's biology makes it both a fundamental research tool and a difficult target for selective therapeutic development.
Peptuno supplies VIP as a lyophilized powder at ≥99.0% HPLC purity. The 28-residue sequence is reliably synthesized but the C-terminal amidation must be confirmed at +1 Da relative to the free-acid form, VIP requires the C-terminal amide for full receptor binding, and unamidated material has substantially reduced activity. The analytical packet covers peak-integration HPLC, mass spec confirming the amidated form, water content, and counter-ion. VIP has a short plasma half-life (1-2 minutes) due to rapid DPP-4 cleavage, which is a feature for acute-pharmacology research and a limitation for chronic-elevation research; engineered VIP analogues with extended half-life (Aviptadil and related modifications) are available on request through Peptuno's custom-synthesis programme.
FAQ
- Why does the C-terminal amidation of VIP matter?
- VIP's C-terminal Asn28 is amidated in the native molecule (giving an Asn-NH₂ rather than a free Asn-COOH), and this amidation is essential for full binding affinity at the VPAC1 and VPAC2 receptors. Unamidated VIP has roughly 10-100-fold lower receptor affinity in published binding studies, which translates to dramatically reduced biological activity in cell-based and in vivo readouts. The analytical confirmation that Peptuno's VIP is the amidated form (rather than the free-acid contaminant from incomplete amidation during synthesis) is the mass-spec check at the theoretical amidated mass, at the +1 Da position relative to the free-acid form.
- What's the difference between VPAC1 and VPAC2 receptors, and does VIP distinguish them?
- VIP binds both VPAC1 and VPAC2 receptors with comparable affinity, it does not pharmacologically distinguish between them. The two receptors are encoded by separate genes (VIPR1 and VIPR2) and have distinct tissue-distribution patterns: VPAC1 is more concentrated in CNS, liver, and lung; VPAC2 is more concentrated in vascular smooth muscle, immune cells, and pancreatic β-cells. Engineered VIP analogs with selective VPAC1 or VPAC2 activity exist as research tools (Bay 55-9837 for VPAC2 selectivity, for example), but native VIP itself is non-selective. Research workflows requiring receptor-selective probing should use the engineered analogs rather than VIP.
Certificate of Analysis (COA)
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