Selank

Origin and Structure of Selank

Tuftsin (Thr-Lys-Pro-Arg) is a natural tetrapeptide isolated from the heavy chain of immunoglobulin G (positions 289-292), first described by Victor Najjar in the 1970s. This peptide attracted research interest due to immunomodulatory properties observed in in vitro models.

Selank extends the tuftsin sequence with the tripeptide Pro-Gly-Pro (PGP), which serves as a proteolytic stabilizer. This C-terminal modification, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences (the same team that created Semax), protects the peptide from amino- and carboxypeptidase degradation, extending the molecule's activity period under research conditions.

Mechanism of Action

Animal model studies indicate that Selank acts on the GABAergic system through allosteric modulation of the GABA-A receptor. In rat experiments, peptide effects on neurotransmitter balance in limbic brain structures were observed, representing a key distinction from the mechanism of Semax, which primarily acts through melanocortin receptors.

Inhibition of enkephalinase activity was also described — enzymes responsible for degradation of endogenous opioid peptides. This mechanism suggests indirect Selank influence on the endogenous opioid system, though the exact nature of these interactions requires further study.

In rodent models, modulation of interleukin 6 (IL-6) and brain-derived neurotrophic factor (BDNF) expression in selected CNS structures was also demonstrated.

Research Overview

Tuftsin and its analogs

Tuftsin was described by Victor Najjar and Kenji Nishioka in Nature (1970, 228:672-673) ^[1]. The authors isolated the tetrapeptide Thr-Lys-Pro-Arg from the Fc fragment of immunoglobulin G and demonstrated its ability to stimulate phagocytosis in leukocyte cultures.

Selank in animal model studies

Seredenin S.B., Kozlovskaya M.M., et al. conducted a series of behavioral studies using Selank in rodent models ^[2]. In elevated plus maze and open field tests, changes in exploratory behavior patterns were observed in rats following peptide administration.

GABA system interactions

Electrophysiological and pharmacological studies demonstrated that Selank modulates GABA-A receptor activity in rodent brain tissue ^[3]. The proposed mechanism involves allosteric interaction with the receptor complex. Inhibition of enkephalinase activity was also described, suggesting indirect effects on endogenous opioid peptide turnover.

Gene expression effects

Molecular studies in rats demonstrated that Selank affects BDNF and interleukin 6 (IL-6) expression in the hippocampus and cerebral cortex, indicating a multi-level biological activity profile in preclinical models.

Structural Features

Selank is a heptapeptide with a mass of ~752 Da, consisting of two functional domains:

• Tuftsin domain (positions 1-4) — Thr-Lys-Pro-Arg, the active fragment responsible for the peptide's biological profile
• PGP stabilizer (positions 5-7) — Pro-Gly-Pro, C-terminal protective tripeptide shared with Semax
• No D-amino acid modifications — all residues in natural L-configuration
• Good solubility — soluble in water and DMSO, facilitating solution preparation

Intended Use

This product is a chemical raw material intended exclusively for in vitro research, scientific, and analytical applications. It is not intended for human or veterinary use, including for diagnostic, therapeutic, prophylactic, or nutritional purposes.

Handling

• Work in laboratory conditions consistent with Good Laboratory Practice (GLP) principles.
• Use appropriate personal protective equipment: nitrile gloves, safety goggles, lab coat.
• Avoid inhalation of dust and contact with skin or mucous membranes.
• Work in a well-ventilated area.

Regulatory Classification

This product is not classified as a hazardous substance under CLP Regulation (EC) No 1272/2008. It is offered as a chemical reagent within the framework of applicable European Union chemical substances regulations (REACH, CLP). It does not constitute a medicinal product, dietary supplement, medical device, or cosmetic within the meaning of applicable laws.

Disposal

Unused material should be disposed of in accordance with local regulations on chemical waste. Under laboratory conditions: neutralize and dispose with laboratory waste streams. Do not discharge into sewage systems.

Regulatory Information

This product is offered in accordance with applicable European Union regulations on chemical substances (REACH, CLP) and Polish law governing the trade of chemical reagents and research materials. Full terms of sale and product classification are set out in the Terms of Service.

By placing an order, the Customer confirms having read the above information and accepts the provisions of the Terms.

Safety Contact

For questions regarding handling or regulatory information: [email protected].