SS-31

SS-31 (also known as Elamipretide or D-Arg-Dmt-Lys-Phe-NH2) is an aromatic-cationic tetrapeptide that targets mitochondrial function at the level of the inner mitochondrial membrane.

SS-31 is designed to selectively concentrate within mitochondria and bind to cardiolipin, a phospholipid found almost exclusively in the inner mitochondrial membrane that has structural and functional roles in mitochondrial bioenergetics.

Mitochondria and Bioenergetics

Mitochondria generate cellular ATP through oxidative phosphorylation and are also sources of reactive oxygen species (ROS). They have roles in cellular signaling, calcium homeostasis, and programmed cell death pathways.

Impaired mitochondrial function can be characterized by reduced ATP production, excessive ROS generation, and disrupted membrane potential.

Mechanism of Action

The peptide's alternating aromatic-cationic structure allows it to cross cellular and mitochondrial membranes and selectively bind to cardiolipin. By binding to cardiolipin, SS-31 influences the structure and function of the inner mitochondrial membrane, which in turn affects the organization of the electron transport chain complexes.

This interaction has been observed in laboratory models to enhance mitochondrial efficiency, reduce electron leak and ROS production, maintain mitochondrial membrane potential, and prevent cytochrome c release under conditions of metabolic stress.

SS-31's mechanism of action involves its interaction with cardiolipin, a dimeric phospholipid that constitutes approximately 20% of the lipid content of the inner mitochondrial membrane.

SS-31 Binding and Effects

SS-31's structure allows it to bind to cardiolipin through electrostatic and hydrophobic interactions. The peptide preferentially binds to cardiolipin over other phospholipids. Once bound, SS-31 has been observed to stabilize cardiolipin molecules and protect them from peroxidative damage in some models.

This stabilization supports the organization and function of ETC complexes, which may enhance their efficiency in electron transfer and ATP synthesis while reducing electron leak and ROS generation at complexes I and III.

Observed Effects in Research Models

By interacting with cardiolipin, SS-31 can influence the cycle of oxidative damage and support mitochondrial function under conditions of metabolic stress. The peptide has been shown to help maintain mitochondrial membrane potential, prevent the mitochondrial permeability transition, and inhibit cytochrome c release in certain experimental settings. SS-31's binding to cardiolipin is reversible and saturable.

In various animal and cellular models, SS-31 has been reported to affect cardiac function, skeletal muscle function, and neuronal viability, and to have an effect in models of ischemia-reperfusion injury.

Published nonclinical literature relevant to this material's molecular targets and experimental models is listed below for independent review. Findings involving other preparations or experimental systems should not be attributed to this research material.

This material is supplied solely for in vitro and other nonclinical laboratory research. It is not for human or veterinary use, consumption, administration, therapeutic use, or diagnostic use.

Laboratory Handling

Handle only in an appropriately equipped laboratory using applicable institutional procedures, personal protective equipment, and the storage conditions shown for the material. The purchaser is responsible for study design, handling controls, disposal, and regulatory compliance.

Research Limitations

Published observations involving other preparations, experimental systems, or study populations do not establish the identity, performance, or suitability of this research material for any particular experiment.