CYP78A1 preferentially expressed in developing inflorescences of Zen mays encoded a cytochrome P450-dependent lauric acid 12-monooxygenase
CYP78A1 preferentially expressed in developing inflorescences of Zen mays encoded a cytochrome P450-dependent lauric acid 12-monooxygenase
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DOI：
10.1271/bbb.64.1696
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发表时间：
2000-08-01
影响因子：
1.6
通讯作者：
Ohkawa, H
中科院分区：
文献类型：
--
作者：
Imaishi, H;Matsuo, S;Ohkawa, H
细胞色素P450（Cytochrome P450，P450）单加氧酶在植物次生代谢产物等亲脂性底物的氧化过程中起重要作用。Larkin报道CYP 78 A1优先在玉米的发育中的花序中表达（Larkin，Plant Mel. 25：343-353，1994）。然而，CYP 78 A1的酶功能尚未完全阐明。为了研究CYP 78 A1的酶活性，本研究将CYP 78 A1 cDNA和烟草或酵母NADPH-细胞色素P450氧化还原酶（P450 reductase）在乙醇脱氢酶启动子I和终止子的控制下，在酿酒酵母AH 22细胞中表达。从表达CYP 78 A1和酵母P450还原酶的转化酵母细胞制备的微粒体组分的还原GO差异光谱在449 nm处显示峰。根据光谱，微粒体组分中P450分子的含量估计为45 pmol P450当量/mg蛋白质。发现含有CYP 78 A1和酵母P450还原酶的重组酵母微粒体催化月桂酸的12-单加氧。基于这些结果，CYP 78 A1优先在玉米的花序发育中表达，似乎参与了脂肪酸的单加氧作用。
Cytochrome P450 (P450 or CYP) monooxygenases play an important role in the oxidation of a number of lipophilic substrates including secondary metabolites in higher plants. Larkin reported that CYP78A1 was preferentially expressed in developing inflorescences of Zea mays (Larkin, Plant Mel. Biol. 25: 343-353, 1994). However, the enzymatic function of CYP78A1 hasn't been clarified yet. To characterized the enzymatic activity of CYP78A1, in this study, CYP78A1 cDNA and tobacco or yeast NADPH-cytochrome P450 oxidoreductase (P450 reductase) was expressed in the yeast Saccharomyces cerevisiae AH22 cells under the control of alcohol dehydrogenase promoter I and terminator. The reduced GO-difference spectrum of a microsomal fraction prepared from the transformed yeast cells expressing CYP78A1 and yeast P450 reductase showed a peak at 449 nm. Based on the spectrum, the content of a P450 molecule was estimated to be 45 pmol P450 equivalent/mg of protein in the microsomal fraction. The recombinant yeast microsomes containing CYP78A1 and yeast P450 reductase were found to catalyze 12-monooxygenation of lauric acid. Based on these results, CYP78A1 preferentially expressed in developing inflorescences of Zea mays appeared to have participated in the monooxygenation of fatty acids.