Point mutation of Cytochrome P450 2A6 (a polymorphic variant CYP2A6.25) confers new substrate specificity towards flavonoids
Point mutation of Cytochrome P450 2A6 (a polymorphic variant CYP2A6.25) confers new substrate specificity towards flavonoids
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细胞色素 P450 2A6（多态性变体 CYP2A6.25）的点突变赋予黄酮类化合物新的底物特异性
DOI：
10.1002/bdd.1966
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发表时间：
2015
影响因子：
2.1
通讯作者：
Imaishi H
中科院分区：
文献类型：
--
作者：
Uno,T.; Ogura,C.;Izumi,C.;Nakamura,M.;Yanase,T.;Yamazaki,H.;Ashida,H.;Kanamaru,K.;Yamagata,H.;Imaishi H
CYP 2A 6是人类细胞色素P450家族的主要肝脏成员。CYP 2A 6 * 25的基因多态性可导致CYP 2A 6水平和活性的许多变化。CYP 2A 6 * 25包含一个氨基酸取代F118 L。为了阐明CYP2A6.25中118位亮氨酸取代的影响，该变体、野生型CYP 2A 6和另外三种由底物结合位点人工突变组成的变体（位置481）由使用随机诱变研究的早期报告[CYP2A6.1、CYP2A6.25、CYP2A6.1（F118 A），CYP2A6.1（A481 G）和CYP2A6.25（A481 G）]与NADPH-细胞色素P450还原酶在E中共表达。杆菌检测了这些变体对7-乙氧基香豆素、香豆素、黄酮、α-萘烷酮、黄烷酮和羟基黄烷酮的羟化酶活性。所有突变体的香豆素7-羟基化活性均低于野生型。与CYP2A6.1相比，所有突变体均显示出更高的黄酮和α-萘啶酮活性。CYP2A6.1具有最高的黄烷酮2′-羟化酶活性，而CYP2A6.25具有最高的6 ′-和4′-羟化酶活性。CYP2A6.1（F118 A）、CYP2A6.1（A481 G）和CYP2A6.25（A481 G）的黄烷酮3′-羟化酶活性高于CYP2A6.1和CYP2A6.25。此外，4′-羟基黄烷酮经CYP2A6.25代谢。这些结果表明，CYP2A6.25突变赋予了对类黄酮的新底物特异性。版权所有© 2015约翰威利父子有限公司.
CYP2A6 is a major hepatic member of the cytochrome P450 family in humans. Much variation in CYP2A6 levels and activity can be attributed to genetic polymorphisms of this gene.CYP2A6*25comprises an amino acid substitution, F118L. To clarify the effect of the leucine substitution at position 118 in CYP2A6.25, this variant, wild type CYP2A6 and three additional variants consisting of artificial mutations at the substrate binding site (position 481) suggested by earlier reports using random mutagenesis studies [CYP2A6.1, CYP2A6.25, CYP2A6.1(F118A), CYP2A6.1(A481G) and CYP2A6.25(A481G)], were co‐expressed with NADPH‐cytochrome P450 reductase inE. coli. The hydroxylase activity of these variants toward 7‐ethoxycoumarin, coumarin, flavone, α‐naphthoflavone, flavanone and hydroxyflavanone were examined. All the mutants had lower activities for coumarin 7‐hydroxylation than the wild type. All the mutants showed higher activities for flavone and α‐naphthoflavone compared with CYP2A6.1. CYP2A6.1 had the highest flavanone 2′‐hydroxylase activity, whereas CYP2A6.25 had the highest 6‐ and 4′‐hydroxylase activities. CYP2A6.1(F118A), CYP2A6.1(A481G) and CYP2A6.25(A481G) had higher flavanone 3′‐hydroxylase activities than CYP2A6.1 and CYP2A6.25. Furthermore, 4′‐hydroxyflavanone was metabolized by CYP2A6.25. These results indicate that the CYP2A6.25 mutation confers new substrate specificity towards flavonoids. Copyright © 2015 John Wiley & Sons, Ltd.