MitoSNO

MitoSNO is a mitochondria-targeted small molecule nitrosylating reagent developed by the MRC Mitochondrial Biology Unit in collaboration with the University of Otago. It is specifically designed to protect heart tissue from ischemia-reperfusion injury following a heart attack. The compound consists of a mitochondria-targeting triphenylphosphonium (TPP) moiety linked to an S-nitrosothiol. MitoSNO rapidly accumulates within the mitochondrial matrix, driven by the membrane potential, where it S-nitrosylates a critical cysteine residue (Cys39 on the ND3 subunit) of mitochondrial Complex I (NADH:ubiquinone oxidoreductase). This covalent modification temporarily locks Complex I in a deactivated state during the initial minutes of reperfusion. By briefly 'switching off' the mitochondria when blood flow returns, MitoSNO prevents the burst of reactive oxygen species (ROS) typically generated by reverse electron transport, thereby reducing oxidative damage and preventing heart cell death.