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Complex I () (also referred to as NADH:ubiquinone oxidoreductase or, especially in the context of the human protein, NADH dehydrogenase (ubiquinone)) is an enzyme of the respiratory chains of myriad organisms from bacteria to humans. It catalyzes the transfer of electrons from NADH to coenzyme Q10 (CoQ10) and, in eukaryotes, it is located in the inner mitochondrial membrane. It is one of the "entry enzymes" of cellular respiration or oxidative phosphorylation in the mitochondria.〔(【引用サイトリンク】title=Protein Data Bank in Europe: Bringing Structure to Biology )〕 ==Function== Complex I is the first enzyme of the mitochondrial electron transport chain. There are three energy-transducing enzymes in the electron transport chain - NADH:ubiquinone oxidoreductase (complex I), Coenzyme Q – cytochrome c reductase (complex III), and cytochrome c oxidase (complex IV). Complex I is the largest and most complicated enzyme of the electron transport chain. The reaction catalyzed by complex I is: :NADH + H+ + CoQ + 4H+in → NAD+ + CoQH2 + 4H+out In this process, the complex translocates four protons across the inner membrane per molecule of oxidized NADH, helping to build the electrochemical potential difference used to produce ATP. The reaction can be reversed - referred to as aerobic succinate-supported NAD+ reduction - in the presence of a high membrane potential, but the exact catalytic mechanism remains unknown. Complex I may have a role in triggering apoptosis. In fact, there has been shown to be a correlation between mitochondrial activities and programmed cell death (PCD) during somatic embryo development. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「NADH:ubiquinone reductase (H+-translocating)」の詳細全文を読む スポンサード リンク
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