SS-31

SS‑31 (also known as elamipretide) is a mitochondria‑targeted tetrapeptide designed to accumulate at the inner mitochondrial membrane through electrostatic and hydrophobic interactions. In mitochondrial preparations, SS‑31 binds with high affinity to cardiolipin, a signature phospholipid of the inner membrane, altering local lipid packing and surface electrostatics without destabilizing bilayer integrity. Cardiolipin binding by SS‑31 has been shown to stabilize respiratory chain organization, enhance electron flux through oxidative phosphorylation complexes, and improve ATP production efficiency in multiple preclinical systems. By limiting cardiolipin oxidation and cytochrome c peroxidase activity, SS‑31 reduces electron leakage and mitochondrial reactive oxygen species (ROS) generation, thereby modulating oxidative‑stress signaling, mitochondrial permeability transition pore (mPTP) dynamics, and apoptosis‑related pathways in cellular and organ models. These combined effects support its use as a tool compound for interrogating mitochondrial quality control, bioenergetics, and organelle‑driven cell‑survival signaling under conditions of metabolic or ischemic stress.