Selank: Research Reference

Selank is a synthetic seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, built from tuftsin, a natural tetrapeptide (Thr-Lys-Pro-Arg), with a Pro-Gly-Pro tail added to its C-terminus to slow its breakdown by enzymes. It is a small, proline-rich, positively charged and very water-soluble peptide, studied in cell and animal models for its effects on GABA signalling, stress behaviour and BDNF.

This reference collects what a laboratory needs to know about Selank as a material: how its seven residues behave in the vial, what it dissolves in, how it is handled at the bench and what to do when an order arrives. Each section below has its own page.

Molecular reference

Name	Selank
Also known as	Selanc, TP-7, threonyl-lysyl-prolyl-arginyl-prolyl-glycyl-proline
Sequence	H-Thr-Lys-Pro-Arg-Pro-Gly-Pro-OH (TKPRPGP; free N-terminal amine and C-terminal acid)
Residues	7
Molecular formula	C33H57N11O9
Molecular weight	751.9 g/mol
CAS number	129954-34-3

Formula, molecular weight, CAS number and synonyms are from PubChem (CID 11765600). The same formula, weight, CAS number and sequence appear in the specifications on our Selank 10 mg product page.

Three features of that sequence explain most of its behaviour. It has no methionine, cysteine, tryptophan, histidine or tyrosine, and no asparagine, glutamine or aspartic acid, so the oxidation, deamidation and aspartate routes that limit many peptides are absent. Three of its seven residues are proline, and the C-terminal Pro-Gly-Pro tail is the same glyproline motif used to make Semax resistant to peptidases (Shevchenko et al., Biomeditsinskaya Khimiya, 2019). And with a lysine, an arginine and a free N-terminal amine against one C-terminal acid, it carries a net positive charge at near-neutral pH, which matters for how it behaves on glass.

What it is studied for

Selank was developed at the Institute of Molecular Genetics in Moscow, the group behind Semax. Much of its mechanism work concerns GABA. In radioligand studies on brain membranes, Selank acted as a positive allosteric modulator of GABA binding, and it blocked the modulating effect of diazepam and olanzapine in the same assay (Vyunova et al., Protein and Peptide Letters, 2018). In cultured neuroblastoma cells it did not change the expression of 84 GABA-system genes on its own, but almost fully suppressed the changes that GABA itself caused (Filatova et al., Frontiers in Pharmacology, 2017).

In rats given ethanol as their only fluid for 30 weeks, Selank prevented the ethanol-induced memory and attention disturbances in an object recognition test and the ethanol-induced rise in BDNF in the hippocampus and frontal cortex (Kolik et al., Bulletin of Experimental Biology and Medicine, 2019). Another line of work concerns enkephalins: in human plasma, Selank inhibited enkephalin-degrading enzymes, acting mainly on carboxypeptidases rather than aminopeptidases (Zolotarev et al., Bioorganicheskaya Khimiya, 2004).

Human data are limited. In a 2008 comparison in 62 people with generalised anxiety disorder or neurasthenia, Selank’s anti-anxiety effect was similar to that of medazepam, with additional anti-fatigue effects (Zozulia et al., Zhurnal Nevrologii i Psikhiatrii, 2008).

Stability

With no oxidation-prone, deamidating or aspartate residues, Selank is chemically simple. In solution its slow routes are general hydrolysis of the backbone and, in principle, ring closure at the N-terminus; enzymes cut it only if they get in. The Selank stability page covers those routes, freeze-thaw, light and what visible changes mean.

Solubility

Selank carries two basic side chains and a computed XLogP of minus 6.1, so it dissolves in bacteriostatic water at once and needs no acid. The Selank solubility guide explains why, which concentrations dissolve cleanly and what causes haze.

Handling

Bench practice for Selank is mostly about keeping the solution cold, clean and labelled. The Selank handling page lists the steps and the common mistakes.

On arrival

What a sealed vial should look like, why it travels without an ice pack and where it and the ready-mixed spray go first are on the Selank on-arrival page.

Storage and reconstitution

Fridge and freezer windows, before and after mixing, are on how long Selank lasts. Water volumes and the concentration table for a 10 mg vial are on how much bacteriostatic water for a Selank 10 mg vial.

FAQ

Short answers to the questions researchers ask most about storing, mixing and handling Selank are on the Selank FAQ.

Where to get it

Vistara Labs supplies Selank 10 mg as a lyophilised vial for laboratory research, shipped within Canada by Canada Post Xpresspost. A ready-mixed Selank Nasal Spray and the Selank + Semax Nasal Spray are also available. Certificates are on our lab reports page. Its closest companion compound, which shares the Pro-Gly-Pro tail, is covered in the Semax research reference.