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Cytochrome P450 reductase (; also known as NADPH:ferrihemoprotein oxidoreductase, NADPH:hemoprotein oxidoreductase, NADPH:P450 oxidoreductase, P450 reductase, POR, CPR, CYPOR) is a membrane-bound enzyme required for electron transfer from NADPH to cytochrome P450 in the endoplasmic reticulum of the eukaryotic cell. == Function == In ''Bacillus megaterium'' and ''Bacillus subtilis'', POR is a C-terminal domain of CYP102, a single-polypeptide self-sufficient soluble P450 system (P450 is an N-terminal domain). The general scheme of electron flow in the POR/P450 system is: }} The definitive evidence for the requirement of POR in cytochrome-P450-mediated reactions came from the work of Lu, Junk and Coon, who dissected the P450-containing mixed function oxidase system into three constituent components: POR, cytochrome P450, and lipids. Since all microsomal P450 enzymes require POR for catalysis, it is expected that disruption of POR would have devastating consequences. POR knockout mice are embryonic lethal, probably due to lack of electron transport to extrahepatic P450 enzymes since liver-specific knockout of POR yields phenotypically and reproductively normal mice that accumulate hepatic lipids and have remarkably diminished capacity of hepatic drug metabolism. The reduction of cytochrome P450 is not the only physiological function of POR. The final step of heme oxidation by mammalian heme oxygenase requires POR and O2. In yeast, POR affects the ferrireductase activity, probably transferring electrons to the flavocytochrome ferric reductase. 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「Cytochrome P450 reductase」の詳細全文を読む スポンサード リンク
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