Selank Nasal Spray Kit

What is Selank?

Selank is a synthetic linear heptapeptide: a chain of seven amino acid residues with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. The compound is known under CAS number 129954-34-3, with the molecular formula C₃₃H₅₇N₁₁O₉ (approx. 751.9 g/mol) and PubChem CID 11765600. The first four residues (Thr-Lys-Pro-Arg) form a naturally occurring tetrapeptide fragment; the tripeptide Pro-Gly-Pro is coupled to this at the C-terminus.

With three proline residues at seven positions, Selank is a distinctly proline-rich chain. The proline-glycine-proline sequence at the C-terminal end increases the rigidity of that part of the chain and limits attack by exopeptidases, making the sequence measurably more stable under laboratory conditions than the unextended tetrapeptide fragment. Additionally, the lysine and arginine residues ensure a distinctly basic charge profile: at neutral pH, the molecule carries a net positive charge, which largely determines its retention behavior in reverse-phase chromatography with ion-pairing additives. Moreover, the chain contains no aromatic residues whatsoever, so detection at 280 nm yields hardly any signal and is typically measured at the peptide bridge around 214 nm. This combination of a short, fully written-out sequence, a rigid C-terminus, and a sharply defined charge profile makes Selank a highly reproducible model compound in comparative peptide research.

Applications in a laboratory context

Within peptide chemistry and analytical work, Selank is involved in the following in vitro research areas, among others:

• Structure-activity relationship research to the contribution of the C-terminal Pro-Gly-Pro motif and of the basic residues to chain conformation, charge distribution, and chromatographic behavior.
• Peptide chemistry research towards solubility and aggregation tendency of strongly basic, proline-rich chains in aqueous media at varying pH and ionic strength.
• Enzymatic stability studies in which the breakdown of the chain is monitored under defined pH, temperature, and enzyme conditions, and the formed fragments are characterized by mass spectrometry.
• Analytical method development and validation (HPLC, LC-MS, peptide mapping) where the absence of aromatic residues requires detection at low wavelengths and the strong basicity of the chain requires carefully chosen ion-pairing conditions.

Specifications

Shape, handling and storage

The material is supplied as a clear, colorless peptide solution in a sealed vial with a closure cap. An aqueous solution is more sensitive to light, heat, and repeated temperature changes than a freeze-dried sample: short chains can hydrolyze slowly in an aqueous environment, and for a basic chain, the charge profile furthermore shifts with the pH of the medium. The vial therefore remains closed in the original packaging until the sample is taken into processing in the laboratory.

Store the vial refrigerated at 2–8 °C, in a dark place and upright, so that the liquid surface does not come into contact with the closure. The usual laboratory precautions apply: work in a clean environment, avoid prolonged exposure to light and ambient temperature, and record the batch number and opening date for each vial in the laboratory logbook so that measurement series remain traceable afterwards.

Analytical quality

In comparative peptide analysis, the purity of the starting material determines how reliably the measurement results can be interpreted: truncation variants, deletion sequences, and degradation fragments produce additional chromatographic peaks that may coincide with the main component, and in the case of a chain lacking an aromatic chromophore, this verification is particularly labor-intensive. Our Selank is supplied with a purity of ≥ 99%, determined by HPLC analysis in accordance with the accompanying 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.