NA-Selank: Tuftsin Analog Research Overview

Tuftsin is an endogenous tetrapeptide (Thr-Lys-Pro-Arg) corresponding to residues 289-292 of immunoglobulin heavy chains. It is released by proteolytic cleavage and acts as a signaling molecule in immune and central nervous system contexts. The peptide was first characterized in 1970 by Najjar and Nishioka.^[1]

NA-Selank (also written N-Acetyl-Selank-Amide) extends the tuftsin sequence with three additional amino acids (Pro-Gly-Pro) plus N-terminal acetylation and C-terminal amidation. These modifications produce a more stable peptide with extended in vitro half-life compared to native tuftsin.^[2]

NA-Selank was developed at the V.V. Zakusov State Institute of Pharmacology of the Russian Academy of Medical Sciences. It is part of the broader Russian neuropeptide research tradition that also produced NA-Semax and related compounds.^[3]

NA-Selank is studied as a research reference compound. It has not been approved by the FDA for any human therapeutic or medical purpose.

NA-Selank structural features:

• Sequence: Thr-Lys-Pro-Arg-Pro-Gly-Pro-NH₂ (7 residues with C-terminal amidation)

• N-terminal: acetylated (Ac-Thr)

• Length: 7 amino acids

• Molecular formula: approximately C₃₃H₅₇N₁₁O₉

• Molecular weight: approximately 751 Da

The three additional residues at the C-terminus (Pro-Gly-Pro) provide steric hindrance against enzymatic degradation while preserving the active tuftsin core sequence. The high proline content (Pro-Gly-Pro tail) contributes to backbone rigidity. N-terminal acetylation blocks aminopeptidase cleavage. C-terminal amidation blocks carboxypeptidase cleavage.^[2]

These combined modifications result in a peptide that retains tuftsin-like biological activity in research preparations but with substantially better in vitro and in vivo stability.

NA-Selank's proposed mechanisms span several neuropeptide signaling pathways.

The endogenous tuftsin receptor remains incompletely characterized in research literature. NA-Selank presumably engages this receptor as a tuftsin analog, but the receptor pharmacology is less well-defined than for compounds targeting receptors with known crystal structures.^[4]

Rodent behavioral models examining anxiety-related endpoints (elevated plus maze, open field test, light-dark box) have been used to characterize NA-Selank effects. The compound has been associated with effects similar to benzodiazepines in some preclinical preparations but without the classical GABA-A receptor pharmacology of those compounds.^[5]

Russian research literature has examined NA-Selank effects on cytokine profiles, BDNF expression, and other signaling markers in animal models. These studies probe the broader signaling impact of the peptide beyond direct receptor engagement.^[6]

NA-Selank research is concentrated in the Russian neuropharmacology literature.

Rodent behavioral assays examining stress response, anxiety-related behaviors, and learning/memory have been used to characterize NA-Selank in preclinical settings.^[5]

BDNF and other neurotrophic factor expression in rodent brain tissue has been examined following NA-Selank administration in preclinical studies.^[6]

NA-Selank's design modifications (acetylation, amidation, Pro-rich C-terminal tail) provide enhanced stability over native tuftsin. Standard peptide handling practices apply.

Lyophilized material is stored at minus 20 degrees Celsius for long-term preservation.

Bacteriostatic water is the standard reconstitution solvent.

HPLC for purity, mass spectrometry for identity confirmation matching the modified heptapeptide mass, and endotoxin screening. Each batch of Instant Peptides NA-Selank ships with a full Certificate of Analysis.

Instant Peptides supplies NA-Selank as a synthetic lyophilized reference compound. Material is supplied to qualified research professionals. Not for human or animal consumption.

View the product page for current pricing and the Certificate of Analysis for the active batch.