SS-31 (Elamipretide)

SS-31 (Elamipretide) is a synthetic mitochondria-targeted tetrapeptide composed of the amino acid sequence D-Arg-dimethylTyr-Lys-Phe-NH₂. It belongs to the class of Szeto–Schiller (SS) peptides, a group of small aromatic-cationic peptides designed to selectively localize within the inner mitochondrial membrane.

Unlike many mitochondria-targeting compounds that rely on membrane potential, SS-31 interacts directly with cardiolipin, a phospholipid unique to the inner mitochondrial membrane that plays a critical role in maintaining the structure and function of the electron transport chain (ETC). Through this interaction, SS-31 has been studied for its ability to stabilize mitochondrial membranes, improve electron transport efficiency, and reduce mitochondrial reactive oxygen species (ROS) production.

Preclinical and clinical research has investigated SS-31 for its potential role in conditions associated with mitochondrial dysfunction, including metabolic disorders, cardiac ischemia-reperfusion injury, skeletal muscle fatigue, and age-related mitochondrial decline. In pharmaceutical development, the peptide is commonly referred to as Elamipretide.

Due to its small size and cationic-aromatic structure, SS-31 is capable of rapid cellular uptake and mitochondrial penetration, allowing it to localize within mitochondria without requiring specialized transport mechanisms.

SS-31 is typically manufactured using solid-phase peptide synthesis (SPPS) and supplied in lyophilized form to preserve stability during storage and transport.