Oxidation of Acenaphthene and Acenaphthylene by Human Cytochrome P450 Enzymes.
Oxidation of Acenaphthene and Acenaphthylene by Human Cytochrome P450 Enzymes.
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DOI：
10.1021/tx500505y
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发表时间：
2015-02-16
影响因子：
4.1
通讯作者：
Komori M
中科院分区：
文献类型：
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作者：
Shimada T;Takenaka S;Murayama N;Yamazaki H;Kim JH;Kim D;Yoshimoto FK;Guengerich FP;Komori M
将苊和苊这两种已知的环境多环芳烃 (PAH) 污染物在标准反应混合物中以 50 µM 浓度与人 P450s 2A6、2A13、1B1、1A2、2C9 和 3A4 一起孵育，并使用 HPLC 和 LC-MS 测定氧化产物。 HPLC分析表明P450 2A6将苊和苊转化为几种单氧化和双氧化产物。 P450 氧化苊的 LC-MS 分析表明，主要产物为 1-苊酚，P450 2A6、2A13 和 1B1 的周转率分别为 6.7、4.5 和 3.6 nmol P450 产物/分钟/nmol P450。 P450 2A6 的苊氧化显示形成 1,2-环氧苊作为主要产物（形成 4.4 nmol 环氧化物/min/nmol P450）以及几种单氧化和双氧化产物。 P450 2A13、1B1、1A2、2C9和3A4分别以0.18、5.3、2.4、0.16和3.8 nmol/min nmol P450的速率形成1,2-环氧苊。 1-苊酚诱导与 P450 2A13 的 I 型结合光谱，并被 P450 2A13 进一步氧化，但 P450 2A6 不氧化。 1,2-环氧苊诱导与 P450 2A6 和 2A13（Ks 分别为 1.8 和 0.16 µM）的 I 型结合光谱，并且还被这些 P450 氧化成多种氧化产物。分子对接分析表明苊、苊、1-苊醇和1,2-环氧苊在与P450 2A6 和2A13 的相互作用中具有不同的方向。这四种多环芳烃均不会诱导鼠伤寒沙门氏菌 NM 测试菌株中的umu基因表达。这些结果首次表明，苊和苊被人 P450 2A6 和 2A13 以及其他 P450 氧化，形成几种单氧化和双氧化产物。这些结果可用于考虑这些环境多环芳烃对人类的生物学和毒理学意义。
Acenaphthene and acenaphthylene, two known environmental polycyclic aromatic hydrocarbon (PAH) pollutants, were incubated at 50 µM concentrations in a standard reaction mixture with human P450s 2A6, 2A13, 1B1, 1A2, 2C9, and 3A4 and the oxidation products were determined using HPLC and LC-MS. HPLC analysis showed that P450 2A6 converted acenaphthene and acenaphthylene to several mono- and di-oxygenated products. LC-MS analysis of acenaphthene oxidation by P450s indicated the formation of 1-acenaphthenol as a major product, with turnover rates of 6.7, 4.5, and 3.6 nmol product formed/min/nmol P450 for P450 2A6, 2A13, and 1B1, respectively. Acenaphthylene oxidation by P450 2A6 showed the formation of 1,2-epoxyacenaphthene as a major product (4.4 nmol epoxide formed/min/nmol P450) and also several mono- and di-oxygenated products. P450 2A13, 1B1, 1A2, 2C9, and 3A4 formed 1,2-epoxyacenaphthene at rates of 0.18, 5.3 2.4, 0.16, and 3.8 nmol/min nmol P450, respectively. 1-Acenaphthenol, which induced Type I binding spectra with P450 2A13, was further oxidized by P450 2A13 but not P450 2A6. 1,2-Epoxyacenaphthene induced Type I binding spectra with P450 2A6 and 2A13 (Ks 1.8 and 0.16 µM, respectively) and was also oxidized to several oxidation products by these P450s. Molecular docking analysis suggested different orientations of acenaphthene, acenaphthylene, 1-acenaphthenol, and 1,2-epoxyacenaphthene in their interactions with P450 2A6 and 2A13. Neither these four PAHs induced umu gene expression in a Salmonella typhimurium NM tester strain. These results suggest, for the first time, that acenaphthene and acenaphthylene are oxidized by human P450s 2A6 and 2A13 and other P450s to form several mono- and di-oxygenated products. The results are of use in considering the biological and toxicological significance of these environmental PAHs in humans.