VIP 10mg

What is VIP?

VIP is a synthetic linear polypeptide composed of twenty-eight amino acid residues, with the 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. The compound bears CAS number 37221-79-7 and has the molecular formula C₁₄₇H₂₃₇N₄₃O₄₃S and a molecular mass of approximately 3326.8 Da (PubChem CID 53314964).

The chain combines an acidic N-terminal segment with two aspartate residues and a distinctly basic middle section containing two arginine and three lysine residues; over the entire sequence, this results in a net basic character and a high isoelectric point. One methionine residue forms the only sulfur-containing and therefore oxidation-sensitive point, while phenylalanine and two tyrosine residues provide the UV absorption. In solution, the molecule adopts an α-helical conformation over a large part of the chain, with the non-polar residues grouping on one side of the helix: an amphipathic pattern that partly determines its behavior on hydrophobic surfaces and retention in reverse-phase chromatography. This combination of chain length, charge distribution, and pronounced helix formation makes VIP a widely used model compound in conformational and structural research on medium-length peptides.

Applications in a laboratory context

Within peptide chemistry and analytical work, VIP occurs in the following in vitro research areas, among others:

• Structure-activity relationship research in which individual residues are substituted to characterize their contribution to helix stability, charge distribution, and amphipathy.
• Peptide chemistry research towards solubility, aggregation, and helix formation of amphipathic chains, by conformation determination via circular dichroism and NMR spectroscopy in aqueous and helix-inducing media such as trifluoroethanol.
• Enzymatic stability studies in which degradation by endo- and exopeptidases is monitored in defined buffer systems; helical segments and flexible ends differ clearly in their accessibility to the enzymes.
• Analytical method development and validation (HPLC, LC-MS, amino acid analysis, peptide mapping) where VIP serves as the reference standard for long synthetic chains, including the assignment of deletion sequences and oxidation products of the methionine residue.

Specifications

Shape, handling and storage

The material is supplied as freeze-dried powder (lyophilisate) in a sealed glass vial with a septum and shrink cap, in a quantity of 10 mg. The freeze-drying process preserves the molecular integrity of the chain during storage and transport. The lyophilisate is white to off-white and presents as a compact cake or as a loose powder; both are normal appearances. The material is hygroscopic and remains closed in the original packaging until it is processed in the laboratory.

Store the unopened lyophilized lyophilized powder refrigerated at 2–8 °C, in a dry and dark place, protected from light and moisture; for longer storage periods, it is usually stored frozen. Allow the vial to reach room temperature before opening to minimize condensation, work in a clean environment, use appropriate personal protective equipment, and prevent cross-contamination with other laboratory materials. Dispose of residual material in accordance with applicable laboratory guidelines.

Analytical quality

For a chain of twenty-eight residues, identity and purity are the determining parameters: deletion sequences, incompletely cleaved protectants, and oxidation of the methionine residue are chromatographically close to the target compound and can influence the interpretation of measurement results. Our VIP is supplied with a purity of ≥ 99%, determined by HPLC analysis in accordance with the corresponding Certificate of Analysis. The available Certificates of Analysis can be viewed on our website. lab results page.

Important disclaimer

We supply this product strictly for laboratory research and analytical work. It is not intended for diagnostic or therapeutic applications, and expressly not for use in humans or animals. This product is not a foodstuff, a supplement, a cosmetic product, or a registered medicinal product. By purchasing this product, the purchaser confirms that they are 18 years of age or older and will use the product exclusively within a controlled research or laboratory environment.