NADH Dehydrogenase Mechanism:
1. The seven primary iron sulfur centers serve to carry electrons from the site of NADH dehydration to ubiquinone. Note that N7 is not found in eukaryotes.
2. There is a reduction of ubiquinone (CoQ) to ubiquinol (CoQH2).
3. The energy from the redox reaction results in conformational change allowing hydrogen ions to pass through four transmembrane helix channels.
Respiratory complex I, EC7.1.1.2 (also known as NADH:ubiquinone oxidoreductase, Type I NADH dehydrogenase and mitochondrial complex I) is the first large protein complex of the respiratory chains of many organisms from bacteria to humans. It catalyzes the transfer of electrons from NADH to coenzyme Q10 (CoQ10) and translocates protons across the inner mitochondrial membrane in eukaryotes or the plasma membrane of bacteria.
This enzyme is essential for the normal functioning of cells, and mutations in its subunits lead to a wide range of inherited neuromuscular and metabolic disorders. Defects in this enzyme are responsible for the development of several pathological processes such as ischemia/reperfusion damage (stroke and cardiac infarction), Parkinson's disease and others.
