What Is Selank? Tuftsin Relationship, Identity and Research Reference
Selank identity in brief
Selank is a defined linear heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its one-letter sequence is TKPRPGP. The first four residues are the complete tuftsin sequence, TKPR; the final three are Pro-Gly-Pro, PGP.
Calling Selank a tuftsin analogue describes that structural relationship. It does not make Selank and tuftsin alternate names for the same molecule. Tuftsin is a four-residue peptide; Selank is a seven-residue peptide with a different formula, molecular mass, and analytical identity.
| Field | Reference value | What the field means |
|---|---|---|
| Standard name | Selank | Common name used in PubChem and the literature |
| Three-letter sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Ordered amino-acid sequence |
| One-letter sequence | TKPRPGP |
Compact sequence notation |
| Residue count | 7 | Selank is a heptapeptide |
| Molecular formula | C33H57N11O9 | PubChem formula for the unmodified neutral sequence |
| Average molecular weight | 751.9 g/mol | PubChem computed average molar mass |
| PubChem CID | 11765600 | NLM compound record |
| CAS Registry Number | 129954-34-3 | Registry identifier associated with Selank |
| Structural description | Tuftsin-related heptapeptide | The tuftsin sequence TKPR followed by PGP |
These values describe the unmodified sequence in the cited PubChem record. A salt, terminally modified analogue, mixture, or mislabeled material needs its own identity evidence; a similar name is not enough.
Selank and tuftsin are related, not identical
NLM PubChem lists tuftsin as Thr-Lys-Pro-Arg, or TKPR, with four residues and an average molecular weight of 500.6 g/mol. It lists Selank as TKPRPGP, with seven residues and an average molecular weight of 751.9 g/mol.
Tuftsin: T K P R
Selank: T K P R P G P
------- -----
tuftsin added PGP segment
sequenceThe shared four-residue sequence supports the phrase “tuftsin analogue.” It does not prove that every tuftsin finding applies to Selank, or that a Selank observation explains tuftsin. The same caution applies to shorter Selank fragments: a fragment result belongs to that fragment under that assay, not automatically to the full heptapeptide.
What representative Selank studies measure
The accessible literature uses several distinct experimental systems. Grouping them under a single pathway label loses the distinctions that make the papers interpretable.
Kolomin et al., 2011, PMID 21609736
- Experimental system
- Mouse spleen sampled at two collection times after Selank or selected fragments
- Measured endpoint
- Real-time PCR panel covering 84 inflammation-related genes
- Interpretation limit
- Spleen transcript changes are not receptor-binding data and do not establish a whole-organism or human outcome
Filatova et al., 2017, PMID 28293190
- Experimental system
- Human IMR-32 neuroblastoma cell culture exposed to Selank alone and in defined combinations
- Measured endpoint
- qPCR panel of 84 genes related to GABAergic signaling and neurotransmission
- Interpretation limit
- Selank alone produced no change in the measured mRNA panel; combination results are not a direct Selank-only effect
Vyunova et al., 2018, PMID 30255741
- Experimental system
- Isolated brain-cell plasma-membrane preparations
- Measured endpoint
- Radioligand binding involving tritiated GABA
- Interpretation limit
- A membrane-binding result is not a behavioral endpoint, clinical comparison, or complete mechanism
Kozlovskaya et al., 2003, PMID 14969422
- Experimental system
- Rat and mouse groups separated by strain and baseline emotional-reactivity characteristics
- Measured endpoint
- Behavioral responses in a conflict-stress design
- Interpretation limit
- Species, strain, selection rules, comparator peptides, and protocol limit generalization
The 2017 cell-line study is especially useful because it preserves a negative result: Selank alone did not alter the measured mRNA panel. Results from combinations cannot be rewritten as direct Selank-only effects. A transcription panel, membrane-binding assay, and rodent behavior also remain separate evidence layers, not proof of one settled mechanism.
The representative papers come largely from related Russian research institutions. That concentration is a replication limitation. Exact material, model, endpoint, collection window, and assay matching remain essential.
How to verify a current Selank lot
A chemical database defines the intended molecule. A lot record reports what a testing laboratory observed in one submitted sample. Connecting the two requires a matching product name, physical lot code, report identifier, and complete analytical record.
Start with BulkGLP’s current and historical batch records. Match the lot printed on the material to the lot shown on the report, then check which attributes the laboratory actually tested. Identity by LC-MS, chromatographic purity by HPLC-UV, and quantitative content are separate results; none substitutes for the other two. The peptide COA guide explains those fields and their limits.
Do not carry a result forward to a later lot. A report supports only the submitted sample and traceability chain it identifies.
Analytical identity is narrower than a compound name
An intact-mass LC-MS result can be consistent with the expected Selank mass, but mass alone may not distinguish every sequence arrangement, isomer, terminal change, or coexisting species. Stronger sequence-level confirmation may require tandem mass spectrometry, peptide mapping, or another orthogonal technique.
HPLC-UV purity is method-dependent. Column chemistry, gradient, mobile phase, detector wavelength, sample preparation, peak assignment, and integration rules affect the reported area percentage. The result is not automatically proof of identity, net peptide content, sterility, or suitability for a biological assay. Traceability remains separate from both methods.
Selank reference questions
What is the amino-acid sequence of Selank?
Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, abbreviated TKPRPGP. PubChem lists formula C33H57N11O9 and an average molecular weight of 751.9 g/mol for the unmodified sequence.
Is Selank another name for tuftsin?
No. Tuftsin is TKPR; Selank is TKPRPGP. The complete tuftsin sequence forms the first four residues of Selank, which is why Selank is described as a tuftsin analogue.
Does the literature prove one settled Selank mechanism?
No. The cited papers use spleen gene-expression panels, a neuroblastoma cell line, membrane radioligand binding, and rodent behavioral designs. These endpoints can inform hypotheses, but they are not interchangeable proof of one complete mechanism.
Does a Selank LC-MS result establish chromatographic purity?
No. LC-MS identity and HPLC-UV purity are separate analytical fields. Quantitative content and lot traceability are separate again.
Does one report apply to every Selank lot?
No. It applies only to the submitted sample identified by that report. Each later lot needs its own matching record.