Molecular cloning and functional characterization of an O-methyltransferase catalyzing 4′-O-methylation of resveratrol in Acorus calamus
Molecular cloning and functional characterization of an O-methyltransferase catalyzing 4′-O-methylation of resveratrol in Acorus calamus
复制标题
DOI：
10.1016/j.jbiosc.2018.10.011
复制
发表时间：
2019-05-01
影响因子：
2.8
通讯作者：
Matsui, Kenji
中科院分区：
文献类型：
--
作者：
Koeduka, Takao;Hatada, Mild;Matsui, Kenji
白藜芦醇及其甲基醚类化合物是一类天然多酚类芪类化合物，在植物防御和人类健康方面具有重要的生物活性。虽然白藜芦醇的生物合成途径已被充分阐明，白藜芦醇特异性O-甲基转移酶的特性仍然难以捉摸。在这项研究中，我们使用RNA-seq分析，以确定一个假定的芳香族O-甲基转移酶基因，AcOMT 1，在菖蒲。在大肠杆菌中表达的重组AcOMT 1对白藜芦醇及其衍生物异甘草素具有高的4 '-O-甲基化活性。我们纯化了AcOMT 1酶促白藜芦醇形成的反应产物，并确认其为4 '-O-甲基白藜芦醇（脱氧漏芦配基）。白藜芦醇和异甘草素是表观K值最高的底物。值分别为1.8 M和4.2 M。重组AcOMT 1表现出对其他白藜芦醇衍生物，白藜芦醇，氧化白藜芦醇，和松芪的活性降低。相反，重组AcOMT 1对紫檀芪或赤松素没有活性。这些结果表明，AcOMT 1对具有非甲基化间苯三酚环的芪类化合物显示出高的4 '-0-甲基化活性。(C)2018年，日本生物技术学会。All rights reserved.
Resveratrol and its methyl ethers, which belong to a class of natural polyphenol stilbenes, play important roles as biologically active compounds in plant defense as well as in human health. Although the biosynthetic pathway of resveratrol has been fully elucidated, the characterization of resveratrol-specific O-methyltransferases remains elusive. In this study, we used RNA-seq analysis to identify a putative aromatic O-methyltransferase gene, AcOMT1, in Acorus calamus. Recombinant AcOMT1 expressed in Escherichia coli showed high 4'-0-methylation activity toward resveratrol and its derivative, isorhapontigenin. We purified a reaction product enzymatically formed from resveratrol by AcOMT1 and confirmed it as 4'-O-methylresveratrol (deoxyrhapontigenin). Resveratrol and isorhapontigenin were the most preferred substrates with apparent K. values of 1.8 M and 4.2 M, respectively. Recombinant AcOMT1 exhibited reduced activity toward other resveratrol derivatives, piceatannol, oxyresveratrol, and pinostilbene. In contrast, recombinant AcOMT1 exhibited no activity toward pterostilbene or pinosylvin. These results indicate that AcOMT1 showed high 4'-0-methylation activity toward stilbenes with non-methylated phloroglucinol rings. (C) 2018, The Society for Biotechnology, Japan. All rights reserved.