Selank Specs: Sequence, MW & CAS
Part of the full Selank guide - a synthetic tuftsin-analogue heptapeptide reference compound, identity-verified with a COA on every vial.
In brief
This section interprets Selank's identifiers - sequence, molecular weight, molecular formula, and CAS number - and explains how its structure maps to its reported function. Every value below is taken directly from the entry.
To the molecule
Molecular specifications
Thr-Lys-Pro-Arg-Pro-Gly-ProThe detail
A closer look
01
Identity and reference values
Selank is classified as a synthetic tuftsin-analogue heptapeptide and a GABAergic and immunomodulatory neuropeptide. Its amino-acid sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, confirming a seven-residue (hepta) peptide. Its molecular weight is 751.87 g/mol (attributed to ChemicalBook), its molecular formula is C33H57N11O9, and its CAS registry number is 129954-34-3. The CAS number is a unique chemical identifier used to disambiguate the exact substance across catalogs and literature, while the molecular formula fixes the elemental composition - 33 carbon, 57 hydrogen, 11 nitrogen, and 9 oxygen atoms - that together account for the 751.87 g/mol mass.
02
Reading the sequence as two functional modules
The sequence is best read as two joined modules. The first four residues, Thr-Lys-Pro-Arg, are the natural immunopeptide tuftsin and carry the immunomodulatory identity that links Selank to interferon and cytokine activity. The final three residues, Pro-Gly-Pro, form the appended C-terminal tail that converts native tuftsin into Selank. This two-module structure is why the entry describes Selank as 'tuftsin (Thr-Lys-Pro-Arg) + Pro-Gly-Pro': the parent peptide supplies the immune-signaling pharmacophore and the added tail supplies engineered stability.
03
Structure-function: the PGP tail
The structural reason the molecule is more than just tuftsin lies in that Pro-Gly-Pro tail. Proline-rich termini are normally cleaved by prolyl endopeptidases, but the PGP arrangement resists that cleavage, which the entry credits with two consequences: markedly extended stability over native tuftsin and improved blood-brain-barrier permeability in research models. Thus the same three residues that distinguish Selank's formula and mass from tuftsin's are also the structural source of its enhanced stability and CNS access - a direct structure-to-function relationship.
04
How specs constrain laboratory math
The molecular weight of 751.87 g/mol is the conversion factor for any mass-to-molar calculation in the laboratory: it relates a measured mass of powder to the number of moles, and therefore to molar concentration once a reconstitution volume is chosen. The molecular formula and CAS number serve verification and procurement roles, letting a researcher confirm that the substance in hand matches the characterized heptapeptide before any in-vitro work begins.
The fine print: products are sold for laboratory research use only and are not for human or animal consumption. Bodily introduction into humans or animals is strictly prohibited by law. Selank is not a drug and is not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the FDA.