SS-31

SS-31 (also known as Elamipretide or MTP-131) is a synthetic tetrapeptide developed by Hazel Szeto and Peter Bhatt at Cornell University. It is a cell-permeable, mitochondria-targeted peptide that selectively concentrates at the inner mitochondrial membrane. SS-31 has been studied in multiple Phase II/III clinical trials for mitochondrial dysfunction conditions by Stealth BioTherapeutics.

SS-31 has a molecular weight of 615.77 g/mol. It contains non-standard amino acids: D-arginine and 2',6'-dimethyltyrosine (Dmt). The alternating aromatic-cationic motif (aromatic: Dmt, Phe; cationic: D-Arg, Lys) enables selective binding to cardiolipin in the inner mitochondrial membrane.

This cardiolipin binding optimizes electron transport chain function and reduces electron leak at complexes I and III.

• Mitochondrial biology: Studies on cardiolipin-cytochrome c interactions and electron transport chain optimization (Szeto, 2014).
• Cardiac biology: Research in ischemia-reperfusion models and heart failure.
• Renal biology: Studies in acute kidney injury and chronic kidney disease models.
• Aging research: Investigations into mitochondrial dysfunction and age-related cellular decline.

• Cardiolipin binding at inner mitochondrial membrane
• Cytochrome c peroxidase activity inhibition
• Electron transport chain complex I/III optimization
• Mitochondrial ROS reduction
• ATP synthesis enhancement in dysfunctional mitochondria

Key preclinical findings:

Szeto (2014): SS-31 selectively bound cardiolipin at the inner mitochondrial membrane, optimizing cytochrome c electron transfer and reducing ROS generation by 60% in isolated cardiac mitochondria. Effective concentration: 1-10 nM.

Birk et al. (2013): SS-31 at 3 mg/kg protected mitochondrial cristae structure during ischemia-reperfusion in murine cardiac model. Preserved ATP synthesis capacity.

Siegel et al. (2013): SS-31 at 0.1-10 µM improved mitochondrial function in aged mouse skeletal muscle. Restored Complex I/III efficiency to near-young levels.

Dai et al. (2014): 8 weeks of SS-31 (3 mg/kg/day) improved diastolic function in aged mice. Reduced mitochondrial ROS and restored cardiolipin content.

Typical in vitro concentrations: 0.1 nM - 10 µM. In vivo: 1-5 mg/kg.

SS-31 (Elamipretide) has been in Phase II/III clinical trials by Stealth BioTherapeutics.

Form: Lyophilized powder, 5mg per vial
Appearance: White to off-white powder
Molecular Weight: 615.77 g/mol
For In Vitro Research Use Only

Laboratory Preparation:
Add sterile diluent to vial. Dissolves rapidly.

Solubility Profile: Freely soluble in water (>50 mg/mL), DMSO, PBS, cell culture media.

Note: SS-31 is cell-permeable and concentrates at the inner mitochondrial membrane in cell culture models (driven by membrane potential and cardiolipin affinity).

Stability: Lyophilized stable 24 months at -20°C. Solution: 30 days at 2-8°C.

Analytical Testing: HPLC, ESI-MS, LAL endotoxin, USP sterility.

This product is for laboratory and in vitro research only. Not for human or animal use.

This content was prepared for informational purposes based on published preclinical research. It does not constitute medical advice or product efficacy claims.

1. 1
   Szeto HH. "First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics." Br J Pharmacol. 2014;171(8):2029-50. PubMed: 24117165 PubMed
2. 2
   Birk AV, et al. "The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin." J Am Soc Nephrol. 2013;24(8):1250-61. PubMed: 23813215 PubMed
3. 3
   Siegel MP, et al. "Mitochondrial-targeted peptide rapidly improves mitochondrial energetics and skeletal muscle performance in aged mice." Aging Cell. 2013;12(5):763-71. PubMed: 23692570 PubMed
4. 4
   Dai DF, et al. "Mitochondrial-targeted catalase: extended longevity and the roles in various disease models." Prog Mol Biol Transl Sci. 2014;127:203-41. PubMed: 25149219 PubMed