红茶加工过程中:茉莉酸羧甲基转移酶功能研究
第一作者
Jing Zhang
第一单位
安农大
通讯作者
Wei-Wei Deng
Abstract
背景+问题:MeJA, a volatile organic compound, is a principal flowery aromatic compound in tea. During the processing of black tea, MeJA is produced by JMT of the JA substrate, forming a specific floral fragrance. The biosynthesis of MeJA in tea plants, especially in tea processing, has not been reported.
主要研究:CsJMT was cloned from the leaves of tea plant, and the function of the encoded protein (CsJMT) was characterized by the prokaryotic expression system (using Escherichia coli)..
结果1:CsJMT was cloned from tea leaves; the three-dimensional structure of CsJMT was predicted. Enzyme activity was identified, and protein purification was investigated. Site-directed deletions revealed that N-10, S-22, and Q-25 residues in the beginning amino acids played a key functional role in enzyme activity.
结果2:The expression patterns of CsJMT in tea organs differed; the highest expression of CsJMT was observed in the fermentation process of black tea.
结论:These results aid in further understanding the synthesis of MeJA during black tea processing, which is crucial for improving black tea quality using specific fragrances and could be applied to the aromatic compound regulation and tea breeding improvement in further studies.
摘 要
茉莉酸甲酯(MeJA)是一种挥发性有机化合物,是茶中的主要花香型芳香化合物。在红茶加工过程中,茉莉酸(JA)底物的茉莉酸羧基甲基转移酶(JMT)产生MeJA,形成特定的花香。 CsJMT是从茶叶中克隆得到的。预测了CsJMT的三维结构。鉴定酶活性,并研究蛋白质纯化。定点删除显示起始氨基酸中的N-10,S-22和Q-25残基在酶活性中起关键功能作用。茶树器官中CsJMT的表达方式不同。在红茶的发酵过程中,CsJMT的表达最高。这些结果有助于进一步理解红茶加工过程中MeJA的合成,这对于使用特定的香料改善红茶质量至关重要,并且可以用于进一步研究中的芳香族化合物调节和茶品系改良。
DOI:https://doi.org/10.1021/acs.jafc.0c06248
Journal: Journal of Agricultural and Food Chemistry
Impact Factor:4.192
Published date: Feb 18, 2021
END
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