Human cytochrome P450 3A4: enzymatic properties of a purified recombinant fusion protein containing NADPH-P450 reductase.

DOI Web Site 被引用文献3件
  • M S Shet
    Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9038.
  • C W Fisher
    Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9038.
  • P L Holmans
    Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9038.
  • R W Estabrook
    Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9038.

抄録

<jats:p>Human cytochrome P450 3A4 is recognized as the catalyst for the oxygen-dependent metabolism of a diverse group of medically important chemicals, including the immunosuppressive agent cyclosporin; macrolide antibiotics, such as erythromycin; drugs such as benzphetamine, nifedipine, and cocaine; and steroids; such as cortisol and testosterone to name but a few. We have engineered the cDNA for human cytochrome P450 3A4 by linkage to the cDNA for the rat or human flavoprotein, NADPH-P450 reductase (NADPH:ferrihemoprotein oxidoreductase, EC 1.6.2.4). An enzymatically active fusion protein (rF450[mHum3A4/mRatOR]L1) has been expressed at high levels in Escherichia coli and purified to homogeneity. Enzymatic studies show a requirement for lipid, detergent, and cytochrome b5 for the 6 beta-hydroxylation of steroids and the N-oxidation of nifedipine. In contrast, these additions are not required for the N-demethylation of erythromycin or benzphetamine. A spectrophotometrically detectable metabolite complex of P450 3A4 is formed during the metabolism of triacetyloleandomycin, and this has a pronounced inhibitory effect on the metabolism of both testosterone and erythromycin. These results relate to the interpretation of current methods used to assess the in vivo activity of P450 3A4.</jats:p>

収録刊行物

被引用文献 (3)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ