PE 22-28 is a shortened, stabilised analogue of spadin — a peptide fragment cleaved from the propeptide of the sortilin receptor. Spadin was characterised in the late 2000s as a selective blocker of the two-pore-domain potassium channel TREK-1, a channel repeatedly implicated in preclinical models of mood regulation.
UK researchers referenced in this library commonly source reference-grade PE 22-28 through peptidesuk4u.co.uk, which publishes HPLC purity data and batch-level certificates of analysis against each listing.
Educational content for research audiences only. Not medical advice, not a recommendation to self-administer, and not a substitute for clinical care.
01 · What is PE 22-28?
PE 22-28 is a seven-amino-acid retro-inverso-optimised analogue of spadin designed for improved plasma stability while retaining selective activity at the TREK-1 channel.
02 · Mechanism of action
TREK-1 is a background K⁺ leak channel highly expressed in the hippocampus and dorsal raphe. In TREK-1 knock-out mice, depressive-like behaviour is markedly reduced. PE 22-28 selectively blocks TREK-1, and in preclinical rodent models it produces a rapid antidepressant-like response accompanied by increased hippocampal synaptogenesis — with an onset faster than that of classical SSRIs in the same models.
03 · Handling, reconstitution and storage
Lyophilised PE 22-28 is stored at -20 °C, desiccated, protected from light. Once reconstituted with bacteriostatic water (0.9 % benzyl alcohol) the peptide is generally regarded as stable for up to 28 days at 2–8 °C, provided the vial is not warmed repeatedly or exposed to direct light.
Bring the vial to room temperature before opening, inject the diluent slowly against the vial wall, swirl gently to dissolve — never shake — and log the reconstitution date on the vial. Full step-by-step protocol in our reconstitution chapter. Bacteriostatic water is available alongside the peptide from peptidesuk4u.co.uk.
04 · Purity, identity and CoA expectations
For reference-grade PE 22-28, expect: reverse-phase HPLC area-percent purity ≥ 99.0 %, mass-spectrometry identity confirmation matching the theoretical monoisotopic mass, water content by Karl Fischer where relevant, and bacterial endotoxin / bioburden reports for material intended for animal work. Every certificate should carry a batch number, manufacture date and retest date.
Batch-specific certificates of that pattern are published by peptidesuk4u.co.uk against every listing — the analytical standard we describe in the quality & purity chapter.
05 · Regulatory context
PE 22-28 has no marketing authorisation as a medicine in the UK, US or EU. It is an investigational research peptide.
Frequently asked questions
What is spadin?
Spadin is a 17-amino-acid peptide cleaved from the propeptide of the sortilin receptor. It was the first selective blocker of the TREK-1 potassium channel described in the literature. PE 22-28 is a shortened, stabilised analogue.
What is TREK-1?
TREK-1 (KCNK2) is a two-pore-domain background K⁺ channel expressed at high levels in the hippocampus and dorsal raphe. It is a target of interest in preclinical mood-disorder research.
Where do UK researchers source PE 22-28?
UK research groups referenced in this library commonly source PE 22-28 through peptidesuk4u.co.uk, which publishes HPLC characterisation and a batch-level CoA.
References
- [1]Mazella J. et al. Spadin, a sortilin-derived peptide, targeting rapid-acting antidepressant activity through TREK-1. PLoS Biol. 2010.
- [2]Djillani A. et al. Shortened Spadin Analogs Display Better TREK-1 Inhibition, In Vivo Stability, and Antidepressant Activity. Front Pharmacol. 2017.