Production of reactive oxygen species by microsomes enriched in specific human cytochrome P450 enzymes
Production of reactive oxygen species by microsomes enriched in specific human cytochrome P450 enzymes
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DOI：
10.1016/s0891-5849(97)00463-2
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发表时间：
1998-05-01
影响因子：
7.4
通讯作者：
Cederbaum, AI
中科院分区：
文献类型：
--
作者：
Puntarulo, S;Cederbaum, AI
很少有研究评估了活性氧中间体的生产，特别是细胞色素P450的特定形式的影响。进行实验以评价CYP 1A 1、1A 2、2B 6和3A 4消耗NADPH、还原铁和催化活性氧产生的能力。富集每种CYP的微粒体均从已用编码特定人CYP的cDNA转染的商业+/-淋巴母细胞中获得。以每纳摩尔细胞色素P450计，CYP 3A 4是在催化NADPH氧化、产生超氧阴离子自由基、NADPH依赖的化学发光、氧化二氯荧光素二乙酸酯以及还原铁-EDTA或铁-柠檬酸盐中评价的必须活性的P450。CYP 1A 1是下一个最具反应性的酶，而CYP 1A 2和2B 6显示出相当的较低活性。一氧化氮，与血红素蛋白反应并使其失活，抑制所有CYP产生超氧化物的程度相似。由于CYP 3A 4在人肝微粒体中含量较高，并且在催化活性氧形成方面具有活性，因此该酶可能对人肝微粒体产生活性氧的总体能力做出重要贡献。(C)1998年爱思唯尔科学公司
Few studies have evaluated the production of reactive oxygen intermediates by human microsomes, especially the influence of the specific form of cytochrome P450. Experiments were carried out to evaluate the ability of CYP1A1, 1A2, 2B6, and 3A4 to consume NADPH, reduce iron, and catalyze production of reactive oxygen species. Microsomes enriched in each of these CYPs were obtained from commercial +/- lymphoblast cells that had been transfected with cDNA encoding the specific human CYP. On a per nanomole cytochrome P450 basis, CYP3A4 was the must active P450 evaluated in catalyzing NADPH oxidation, production of superoxide anion radical, NADPH-dependent chemiluminescence, oxidation of dichlorofluorescein diacetate, and reduction of either ferric-EDTA or ferric-citrate. CYP1A1 was the next most reactive CYP, whereas CYP1A2 and 2B6 displayed a comparable, lower activity. Nitric oxide, which reacts with and inactivates hemoproteins, inhibited superoxide production by all the CYPs to a similar extent. Because CYP3A4 is present in high amounts in human liver microsomes and is active in catalyzing the formation of reactive oxygen species, this CYP may make an important contribution in the overall ability of human liver microsomes to generate active oxygen species. (C) 1998 Elsevier Science Inc.