SS-31

SS-31 is a synthetic research peptide with the sequence D-Arg-Dmt-Lys-Phe-NH₂ from the Szeto-Schiller family of mitochondria-targeting compounds. SS-31 peptide was discovered by Dr. Hazel Szeto at Weill Cornell Medical College and is designed to address mitochondrial dysfunction across cardiovascular, neurodegenerative, metabolic, and muscle-related research. This SS-31 tetrapeptide has garnered significant interest for its therapeutic potential in conditions including cardiovascular disease, neurodegeneration, and metabolic syndrome.

SS-31 exerts its effects through highly selective targeting of the inner mitochondrial membrane. It selectively binds to cardiolipin (CL), a unique phospholipid found almost exclusively in the inner mitochondrial membrane. This binding stabilizes mitochondrial cristae structure, reduces oxidative stress, and enhances adenosine triphosphate (ATP) production. SS-31 also inhibits the peroxidase activity of cytochrome c (cytc), enhancing electron transfer while reducing electron leakage, and prevents the opening of the mitochondrial permeability transition pore that forms under mitochondrial stress. Through these mechanisms, SS-31 improves mitochondrial bioenergetics, minimizes oxidative stress, and restores mitochondrial function in energy-depleted cells.

• Cardiovascular Research: Investigated for protective effects in heart failure, ischemia-reperfusion injury, and myocardial infarction. Clinical trials such as PROGRESS-HF have evaluated its efficacy in heart failure patients.
• Mitochondrial Myopathy: Studied in primary mitochondrial myopathy through the MMPOWER-3 Phase 3 clinical trial.
• Neurodegenerative Diseases: Employed in preclinical models to evaluate neuroprotective effects in traumatic brain injury, stroke, Alzheimer's disease, and Parkinson's disease.
• Rare Genetic Disorders: Investigated for Barth syndrome (BTHS), with FDA Rare Pediatric Disease designation, and Friedreich's ataxia.
• Age-Related Conditions: Studied for dry age-related macular degeneration and improving mitochondrial function in aged oocytes.

CAS Number: 736992-21-5 (free base); 1334953-95-5 (acetate salt)
Molecular Formula: C₃₂H₄₉N₉O₅
Molecular Weight: 639.79 g/mol
Sequence: D-Arg-Dmt-Lys-Phe-NH₂ (Dmt = 2,6-dimethyl-L-tyrosine)
Purity: ≥ 98% (batch-dependent; refer to Certificate of Analysis)
Form: Lyophilized powder
Storage: Store at ≤ -20°C in a cool, dry place, protected from light and moisture
Solubility: Soluble in sterile water, PBS (pH 7.2), and DMSO; prepare working solutions per laboratory protocol