Mitochondrial NADH:ubiquinone oxidoreductase (Complex I)

Mitochondrial NADH:ubiquinone oxidoreductase (Complex I) is the largest and first enzyme complex of the mitochondrial respiratory chain, located in the inner mitochondrial membrane. It catalyzes the oxidation of NADH to NAD⁺ and transfers electrons to ubiquinone (coenzyme Q10), coupled to the translocation of protons across the membrane. This process is essential for oxidative phosphorylation and ATP production. Complex I is composed of 44 subunits in mammals and plays key roles in cellular energy metabolism, generation of mitochondrial membrane potential, and regulation of oxidative stress. Mutations or dysfunctions in this complex are implicated in numerous human diseases including mitochondrial encephalopathies, Parkinson’s disease, and cardiac and neurological disorders linked to oxidative stress and impaired energy metabolism[1][3][4][5][6][7][9].

Other names

Respiratory complex IType I NADH dehydrogenaseMitochondrial complex IEC 7.1.1.2

Inhibition of electron transfer, Disruption of proton translocation, Modulation of ROS production