Compound monograph
PE 22-28
PE 22-28 is a synthetic heptapeptide corresponding to residues 22 to 28 of the sortilin propeptide. It is not a fragment of spexin; see the nomenclature note.
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Identity & nomenclature
PE 22-28 is a synthetic heptapeptide corresponding to residues 22 to 28 of the sortilin propeptide. It is not a fragment of spexin; see the nomenclature note.
CORRECTION, 2026-09-13. This entry previously described PE 22-28 as residues 22 to 28 of spexin and carried the alias Spexin (22-28). That was wrong, and it is wrong for a reason that can be checked without any source: mature spexin is fourteen residues long, so residues 22 to 28 of it do not exist, and the sequence Gly-Val-Ser-Trp-Gly-Leu-Arg appears nowhere within spexin's sequence Asn-Trp-Thr-Pro-Gln-Ala-Met-Leu-Tyr-Leu-Lys-Gly-Ala-Gln. The PE in PE 22-28 denotes the sortilin propeptide, not a peptide. Gly-Val-Ser-Trp-Gly-Leu-Arg is residues 22 to 28 of that propeptide, and the same seven residues form the C-terminal end of the longer sortilin-propeptide-derived peptide spadin. PE 22-28 has no sequence relationship to spexin at all.
Declared aliases and development codes: PE(22-28), Sortilin propeptide (22-28).
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Molecular properties
| Molecular formula | C35H55N11O9 |
|---|---|
| Molecular mass | 773.9 Da |
| PubChem CID | 165437303 |
| One-letter sequence | GVSWGLR |
| Three-letter sequence | Gly–Val–Ser–Trp–Gly–Leu–Arg |
| Terminal groups | Free N-terminus; Free C-terminal carboxyl |
Heptapeptide Gly-Val-Ser-Trp-Gly-Leu-Arg. The PE in the name denotes the sortilin PROPEPTIDE, and 22 to 28 are its residue positions within that propeptide — not within any peptide called PE.
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Structural characteristics
PE 22-28 was designed from degradation products of spadin, which derives from the sortilin propeptide. Patch-clamp experiments in hTREK-1/HEK cells measured TREK-1 inhibition at approximately 0.1 nM, against 40-60 nM for spadin. That source is internally inconsistent about which peptide carries which value: its abstract and results report 0.12 nM for PE 22-28 and 0.10 nM for the Gly22-Ala analog, while its figure legend and discussion transpose the two. No single figure is reproduced here as though the source agreed with itself. This is direct evidence about the heptapeptide in that assay. The related founding spadin study provides propeptide and channel-binding context. The sequence contains one tryptophan, its only aromatic residue.
Terminal features: Free N-terminus, Free C-terminal carboxyl.
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Molecular targets & mechanisms
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Analytical considerations
The single tryptophan provides a UV chromophore near 280 nm, unlike several other short peptides in this library. PubChem CID 165437303 encodes free-terminal GVSWGLR and includes CAS 1801959-12-5 and acetate wording among synonyms, but its structure contains no acetate and the CAS assignment remains independently unconfirmed. The seven-residue sequence must be established directly: a heptapeptide cannot be confirmed by demonstrating that its residues appear inside a longer peptide, and a response attributed to a related longer peptide is not identity evidence for this one.
Disagreements and mix-ups
Points where sources disagree about this compound's identity, or where a name or form is easily confused with another, as noted in this record. The discrepancy register quotes the passage for each one.
Often mixed up · Name or substance
PE 22-28 is not a fragment of spexinAlso noted in Spexin
What the studies reported
Each finding describes one cited study in its stated model. These observations are specific to that study and do not establish effects in other settings.
Cell and tissue studies
hTREK-1-expressing HEK cells studied by patch clamp
In hTREK-1-expressing HEK cells studied by patch clamp, the study abstract reported a PE 22-28 IC50 of 0.12 nM for TREK-1 channel inhibition.
Reference [1]Mouse cortical neurons
In mouse cortical neurons, the study reported increased PSD-95 expression with PE 22-28 and its derivatives.
Reference [1]HEK cells expressing hTREK-2, hTRAAK, hTRESK or hTASK-1 channels
In HEK cells expressing hTREK-2, hTRAAK, hTRESK or hTASK-1 channels, the study observed no change in channel currents with PE 22-28.
Reference [1]
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Verified bibliography
Cited studies by type
The 2 papers this record cites, counted by the kind of work each reports. A count is the size of this record's selection, not of the research that exists, and says nothing about results, safety, effectiveness or approval.
A paper can report more than one kind of work. Each count opens those papers in the bibliography. Compare every record on the Evidence Map.
Reference 1
Shortened Spadin Analogs Display Better TREK-1 Inhibition, In Vivo Stability and Antidepressant Activity.Djillani A, Pietri M, Moreno S, Heurteaux C, Mazella J, Borsotto M
Frontiers in pharmacology · 2017-09-12 · Journal Article
currentReference 2
Spadin, a sortilin-derived peptide, targeting rodent TREK-1 channels: a new concept in the antidepressant drug design.Mazella J, Pétrault O, Lucas G, Deval E, Béraud-Dufour S, Gandin C, El-Yacoubi M, Widmann C, Guyon A, Chevet E, Taouji S, Conductier G, Corinus A, Coppola T, Gobbi G, Nahon JL, Heurteaux C, Borsotto M
PLoS biology · 2010-04-13 · Journal Article
current
Study models of these references
What kind of experiment each cited paper reports, taken from its abstract unless marked. Not a summary of results.
| Reference | Study models |
|---|---|
| Djillani A et al. 2017 | Study models reported: in vitro; animal (mouse) · from the abstract |
| Mazella J et al. 2010 | Study models reported: in vitro; animal (mouse) · from the abstract |
Record history
Published 2026-09-12.
- : Sequence and structure
- : Analytical notes
- : Identity and nomenclature
- : Sequence and structure
- : Identity and nomenclature, Sequence and structure, References
- : Identity and nomenclature, Sequence and structure, Analytical notes
Each entry names the parts of this record that changed on that date. Changes to links between records and to catalogue links are not listed. This history covers the tracked record fields; study findings are not listed here.
Cite this record: Purely Peptides Research Library. PE 22-28. Published 2026-09-12; updated 2026-10-14. https://purelypeptides.org/research/compounds/pe-22-28/
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Methodology & citation verification
Reference identity is checked against official PubMed metadata. Local deterministic receipts bind each normalized title and canonical metadata record to its verification date. Scientific values remain absent when an authoritative source has not been verified.
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