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SS-31 (Elamipretide)

SS-31 (elamipretide, CAS 330461-58-0) is a synthetic tetrapeptide (D-Arg-Dmt-Lys-Phe-NH₂) from the Szeto-Schiller class of mitochondria-targeted aromatic-cationic peptides, with a molecular weight of approximately 639.8 Da. Designed to selectively accumulate in the inner mitochondrial membrane driven by the mitochondrial membrane potential (ΔΨm), SS-31 is a premier research tool for studying mitochondrial bioenergetics, cardiolipin-mediated electron transport chain function, and oxidative stress mitigation.

Technical Specifications

Property Value
CAS Number 330461-58-0
Molecular Formula C₃₂H₄₉N₉O₅
Molecular Weight ~639.8 Da
Purity ≥98% (HPLC-verified)
Appearance Lyophilized white powder
Solubility Soluble in sterile water and aqueous buffers
Storage -20°C (lyophilized), 2–8°C (reconstituted)

Mechanism of Action

SS-31 selectively partitions to the inner mitochondrial membrane (IMM) in a membrane potential-dependent manner, achieving local concentrations 1,000–5,000-fold greater than extracellular levels within minutes of exposure. Once localized to the IMM, SS-31 binds with high affinity to cardiolipin — a phospholipid unique to the mitochondrial inner membrane that serves as a structural and functional anchor for electron transport chain (ETC) complexes and cytochrome c. By stabilizing cardiolipin against peroxidative damage from reactive oxygen species (ROS), SS-31 preserves the quaternary organization of ETC supercomplexes, maintains cristae architecture, and prevents cytochrome c release into the intermembrane space — a key initiating event in mitochondrial apoptosis. SS-31 also reduces mitochondrial ROS production by improving electron flow efficiency through Complexes I, III, and IV, without functioning as a direct free radical scavenger. This cardiolipin-stabilizing mechanism distinguishes SS-31 from conventional antioxidants and enables targeted organelle-level cytoprotection.

Research Applications

  • Primary: Mitochondrial bioenergetics — cardiolipin stabilization, ETC complex function, oxidative phosphorylation
  • Secondary: Ischemia-reperfusion injury models, heart failure with preserved ejection fraction (HFpEF), neurodegenerative disease mitochondrial dysfunction
  • Model Systems: In vitro (isolated mitochondria, cardiomyocyte cell lines, neuronal cultures), in vivo (myocardial infarction rodent models, renal ischemia-reperfusion, Barth syndrome models)

Quality Control & Analytical Methods

  • HPLC: ≥98% purity verification at 214/220 nm (C18 reversed-phase column)
  • Mass Spectrometry: ESI-MS for molecular weight confirmation (~639.8 Da)
  • Peptide Content: Amino acid analysis (AAA) for net peptide content determination
  • Endotoxin: <1 EU/mg (LAL assay)
  • TFA Content: <1% (ion chromatography)

Stability & Storage

Condition Stability
-20°C (lyophilized) 24 months
4°C (lyophilized) 6 months
25°C (lyophilized) 1 month
Reconstituted (4°C) 7 days
Reconstituted (-20°C) 30 days

Key Research References

  • Szeto (2006) — Cell-permeable, mitochondrial-targeted, peptide antioxidants. AAPS J. PMID: 17025270
  • Birk et al. (2014) — The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin. J Am Soc Nephrol. PMID: 24482202
  • Dai et al. (2014) — Bendavia, a mitochondria-targeting peptide, improves post-infarction cardiac function. Circulation. PMID: 24700782

Source & Purchase

For researchers requiring research-grade SS 31 with full analytical documentation including HPLC, LC-MS, and Certificate of Analysis, visit the HK Peptides product page for specifications, bulk pricing, and ordering.

View SS 31 Product →

FAQ

Q: What purity level is standard for SS-31? A: HK Peptides supplies SS-31 at ≥98% purity by HPLC with full COA documentation.

Q: How should SS-31 be stored for research use? A: Lyophilized SS-31 should be stored at -20°C. Reconstituted solutions at 4°C for short-term use (up to 7 days).