Selank: The Synthetic Tuftsin Analogue and GABAergic Modulator
A detailed analysis of Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro), a heptapeptide analogue of endogenous tuftsin studied for its interactions with the GABAergic system, immune modulation, and anxiolytic properties.
Introduction
Selank is a synthetic heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) structurally related to the endogenous immunomodulatory tetrapeptide tuftsin. Developed at the Institute of Molecular Genetics in Moscow, Selank has been the subject of extensive preclinical investigation for its unique dual action on the nervous and immune systems.
Chemical Profile
- Sequence: Thr-Lys-Pro-Arg-Pro-Gly-Pro
- Molecular Formula: C33H55N11O8
- Molecular Weight: ~751.9 g/mol
- CAS Number: 129954-34-3
- Appearance: White to off-white lyophilized powder
The addition of a Pro-Gly-Pro C-terminal extension to tuftsin (TKPR) confers enhanced metabolic stability and central activity that the parent tetrapeptide lacks.
Mechanism of Action
GABAergic System Modulation
Selank's most notable pharmacological property is its modulation of the GABAergic system. Unlike benzodiazepines, which act directly on GABA-A receptors, Selank influences GABA metabolism and receptor expression:
- Upregulates GABA-A receptor expression in the prefrontal cortex
- Modulates the activity of GABA transaminase (GABA-T), the primary enzyme responsible for GABA degradation
- Does not produce the sedation, tolerance, or dependence associated with classical GABAergic drugs
Immunomodulatory Activity
As a tuftsin analogue, Selank retains immunomodulatory properties:
- Modulates cytokine expression (IL-6, IL-1-beta, TNF-alpha)
- Influences T-cell proliferation and differentiation
- Affects natural killer (NK) cell activity
Enkephalin Degradation Inhibition
Selank inhibits enkephalin-degrading enzymes, particularly leu-enkephalin degradation. This property may contribute to its anxiolytic and cognitive-enhancing effects through the endogenous opioid system.
Preclinical Research Findings
Anxiolytic Effects
In elevated plus maze and open field tests, Selank demonstrates significant anxiolytic activity:
- Increases time spent in open arms of the EPM by 35-50%
- Does not impair motor coordination or cognitive function
- Shows no withdrawal syndrome upon discontinuation
Cognitive Enhancement
- Improves attention and information processing speed
- Enhances memory consolidation in passive avoidance paradigms
- Reduces cognitive deficits induced by chronic stress
Antiviral Properties
Studies have shown Selank can modulate interferon production and enhance the antiviral immune response, particularly against RNA viruses.
Comparative Analysis: Selank vs Semax
| Property | Selank | Semax |
|---|---|---|
| Parent peptide | Tuftsin (TKPR) | ACTH(4-7) |
| Primary system | GABAergic | Melanocortinergic |
| Key effect | Anxiolytic | Nootropic |
| Neurotrophin effect | Moderate BDNF | Strong BDNF/NGF |
| Immunomodulation | Strong (tuftsin analogue) | Moderate |
| CAS | 129954-34-3 | 80714-61-0 |
Storage and Handling
- Store lyophilized powder at -20C
- Protect from moisture and light
- Reconstitute with bacteriostatic water
- Reconstituted solutions stable for 30 days at 2-8C
Conclusion
Selank represents a unique pharmacological tool that bridges neuroscience and immunology research. Its dual action on GABAergic signalling and immune modulation makes it particularly valuable for studies investigating the neuroimmune axis.
All products sold by Kingston Peptides are intended exclusively for in vitro research and analytical purposes.