ND2 Background Information NADH dehydrogenase (complex I) is a complicated multiprotein complex located in the inner mitochondrial membrane. Human complex I is important for energy metabolism because its main function is to transport electrons from NADH to ubiquinone, which is accompanied by translocation of protons from the mitochondrial matrix to the intermembrane space to produce ATP. The largest of respiratory units, human complex I appears to consist of 41 subunits with 45 separate polypeptide chains. A small number of complex I subunits are the products of mitochondrial genes (subunits 1-7), while the remainder are nuclear encoded and imported from the cytoplasm. Various tissues from patients with neurodegenerative disease are frequently deficient in complex I. NADH dehydrogenase 2 (ND2) is a copper-containing NADH dehydrogenase which also retains cupric reductase activity involved in hydroperoxide-induced oxidative stress. ND2 maintains integrated roles in bacterial oxidative protection and also copper homeostasis.
