SS-31 (INN elamipretide) is an aromatic-cationic tetrapeptide from the Szeto-Schiller family, engineered to accumulate on the inner mitochondrial membrane through selective binding to cardiolipin. It is one of the best-defined mitochondria-targeting peptides in the literature.
UK researchers referenced in this library commonly source reference-grade SS-31 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 SS-31?
SS-31 is a synthetic tetrapeptide with an unusual alternating aromatic-cationic motif that carries a net +3 charge at physiological pH and concentrates 1000-fold on the inner mitochondrial membrane relative to cytosol.
02 · Mechanism of action
SS-31 binds cardiolipin on the inner mitochondrial membrane. Cardiolipin is essential for the structural organisation of the electron-transport-chain supercomplexes; in disease states cardiolipin peroxidation disrupts this organisation and impairs ATP synthesis. SS-31 protects cardiolipin from peroxidation, preserves cristae architecture and restores electron-transport efficiency in models of ischaemia-reperfusion, heart failure and primary mitochondrial disease.
03 · Handling, reconstitution and storage
Lyophilised SS-31 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 SS-31, 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
Elamipretide is an investigational drug studied in Barth syndrome and primary mitochondrial myopathy. It does not currently have a marketing authorisation in the UK, US or EU. Research-grade SS-31 is supplied as a laboratory reagent only.
Frequently asked questions
What is cardiolipin?
Cardiolipin is a phospholipid unique to the inner mitochondrial membrane. It is essential for the assembly of the electron-transport-chain supercomplexes and is a required binding partner for SS-31.
Is SS-31 an antioxidant?
SS-31 protects cardiolipin from peroxidation by concentrating on the inner mitochondrial membrane. It is more accurately described as a mitochondria-targeting cardiolipin-binding peptide than as a generic antioxidant.
Where do UK researchers source SS-31?
UK research groups referenced in this library commonly source SS-31 through peptidesuk4u.co.uk, which publishes HPLC characterisation and a batch-level CoA.
References
- [1]Szeto H.H. First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics. Br J Pharmacol. 2014.
- [2]Karaa A. et al. Randomized trial of elamipretide in primary mitochondrial myopathy. Neurology. 2018.