Summary
SS-31 (also known as elamipretide or MTP-131) is a cell-permeable tetrapeptide that selectively targets the inner mitochondrial membrane. It binds to cardiolipin and is studied in literature on mitochondrial-membrane stability and bioenergetics.
Overview
SS-31 is one of the Szeto-Schiller (SS) peptide family — a set of small mitochondria-targeting peptides identified by Hazel Szeto and Peter Schiller in the early 2000s. It localizes selectively to the inner mitochondrial membrane through a sequence-specific affinity for cardiolipin, the signature phospholipid of that membrane.
Research Background
The SS peptide family was developed by Szeto and Schiller as cell-permeable tetrapeptides with alternating aromatic and basic residues. The mitochondrial targeting derives from this specific structural motif rather than from a classical mitochondrial-targeting sequence. SS-31 (D-Arg-2,6-dimethyl-Tyr-Lys-Phe-NH2) is the most-studied member of the family.
Mechanisms Studied
Mechanistic interest centers on selective cardiolipin binding, stabilization of the inner mitochondrial membrane and electron-transport-chain organization, and downstream effects on oxidative phosphorylation efficiency and reactive-oxygen-species generation. The cardiolipin interaction is the defining feature distinguishing SS peptides from other antioxidants.
Published Research Summary
Szeto (2014) reviews the SS peptide family. Birk et al. (2013) characterize the cardiolipin binding and its consequences for cytochrome c interaction. A growing literature has characterized SS-31 across cell-culture and animal-model systems with mitochondrial dysfunction.
Quality & Verification
For research compounds, lot-level documentation is the starting point for any analytical work. Researchers commonly examine batch-specific Certificates of Analysis, reversed-phase HPLC purity readouts, mass-spectrometry confirmation of molecular weight, and lot identification to evaluate compound identity, purity, and consistency before downstream experiments.
References & Published Research
- Szeto HH — First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics (review)
- Birk AV et al. — The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin
- Zhao K et al. — Cell-permeable peptide antioxidants targeted to inner mitochondrial membrane inhibit mitochondrial swelling, oxidative cell death, and reperfusion injury