Mitochondrial enzyme complex (Complex I)

The **mitochondrial enzyme complex** most frequently refers to large, multi-protein assemblies embedded in the inner mitochondrial membrane, such as Complex I (NADH:ubiquinone oxidoreductase), which initiates the electron transport chain by catalyzing electron transfer from NADH to ubiquinone while pumping protons to generate a membrane potential essential for ATP synthesis[3][1][5][7]. Complex I is an L-shaped structure with a peripheral (matrix) and membrane arm, comprising at least 44 subunits in mammals, and its activity is tightly linked to cellular energy metabolism, ROS generation, and regulation of apoptosis[3][5][7][8]. Dysfunction or mutation of its subunits is the most common cause of inherited mitochondrial diseases and is implicated in neurodegenerative disorders and aging[5][6][3]. Complex I and other mitochondrial enzyme complexes are clinically relevant drug targets, but targeting them poses substantial delivery, toxicity, and selectivity challenges in therapeutic development[2][8]. **Note:** For database curation and structured annotation, explicitly enumerate which mitochondrial enzyme complex (e.g., “NADH:ubiquinone oxidoreductase” or “Succinate dehydrogenase”) is meant if possible. “Mitochondrial enzyme complex” is too generic and should be replaced by a specific complex name wherever feasible[5][7].

Other names

Respiratory complex INADH dehydrogenase (Complex I)Mitochondrial respiratory complex(es)ETC complex (Electron Transport Chain complex)

Inhibition of electron transport/Complex I function (impair ATP synthesis, increase ROS production, induce apoptosis); Disruption of proton gradient (using uncouplers like niclosamide, FCCP, etc.)