Partial reconstruction of flavonoid and isoflavonoid biosynthesis in yeast using soybean type I and type II chalcone isomerases
Partial reconstruction of flavonoid and isoflavonoid biosynthesis in yeast using soybean type I and type II chalcone isomerases
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DOI：
10.1104/pp.104.054502
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发表时间：
2005-04-01
期刊：
影响因子：
7.4
通讯作者：
Yu, O
中科院分区：
文献类型：
--
作者：
Ralston, L;Subramanian, S;Yu, O
黄酮类化合物和异黄酮类化合物是介导多种生物功能的重要植物次生代谢产物，具有重要的生态效应。这些化合物在许多重要的生理过程中起着重要作用。此外，类黄酮和异类黄酮对人类健康有直接而复杂的影响，从降低胆固醇水平、预防某些癌症到改善妇女健康。在这项研究中，我们克隆了5个大豆（甘氨酸max）查尔酮异构酶（CHIs），并对它们进行了功能表征，这些酶是苯丙素途径中产生黄酮类和异黄酮的关键酶。基因表达和动力学分析表明，以柚皮素查尔酮为底物的大豆I型CHI与其他类黄酮特异性基因协同调控，而以多种查尔酮为底物的大豆II型CHI则与一个异黄酮特异性基因协同调控，并被结瘤信号特异性激活。此外，我们发现一些新鉴定的大豆CHIs不需要4'-羟基部分。酶活性高的底物。然后我们改造酵母（Saccharomyces cerevisiae）产生类黄酮和异黄酮化合物。当其中一种11型CHIs与异黄酮合成酶（异黄酮合成酶催化异黄酮生物合成的第一步）共表达时，添加到培养基中的各种查尔酮底物被转化为各种异黄酮和异黄酮。我们还通过与黄酮3 β -羟化酶或黄酮合成酶II共表达CHI，重建了黄酮途径。酵母体内类黄酮和异黄酮途径的重建为研究酶相互作用和代谢通量提供了一个独特的平台。
Flavonoids and isoflavonoids are major plant secondary metabolites that mediate diverse biological functions and exert significant ecological impacts. These compounds play important roles in many essential physiological processes. In addition, flavonoids and isoflavonoids have direct but complex effects on human health, ranging from reducing cholesterol levels and preventing certain cancers to improving women's health. In this study, we cloned and functionally characterized five soybean (Glycine max) chalcone isomerases (CHIs), key enzymes in the phenylpropanoid pathway that produces flavonoids and isoflavonoids. Gene expression and kinetics analysis suggest that the soybean type I CHI, which uses naringenin chalcone as substrate, is coordinately regulated with other flavonoid-specific genes, while the type II CHIs, which use a variety of chalcone substrates, are coordinately regulated with an isoflavonoid-specific gene and specifically activated by nodulation signals. Furthermore, we found that some of the newly identified soybean CHIs do not require the 4'-hydroxy moiety on. the substrate for high enzyme activity. We then engineered yeast (Saccharomyces cerevisiae) to produce flavonoid and isoflavonoid compounds. When one of the type 11 CHIs was coexpressed with an isoflavone synthase, the enzyme catalyzing the first committed step of isoflavonoid biosynthesis, various chalcone substrates added to the culture media were converted to an assortment of isoflavanones and isoflavones. We also reconstructed the flavonoid pathway by coexpressing CHI with either flavanone 3 beta-hydroxylase or flavone synthase II. The in vivo reconstruction of the flavonoid and isoflavonoid pathways in yeast provides a unique platform to study enzyme interactions and metabolic flux.