Functional Characterization of a New Tea (<i>Camellia sinensis</i>) Flavonoid Glycosyltransferase
Xianqian Zhao
Peiqiang Wang
Mingzhuo Li
Yeru Wang
Xiaolan Jiang
Lilan Cui
Yumei Qian
Juhua Zhuang
Liping Gao
Tao Xia
10.1021/acs.jafc.6b05619.s001
https://acs.figshare.com/articles/journal_contribution/Functional_Characterization_of_a_New_Tea_i_Camellia_sinensis_i_Flavonoid_Glycosyltransferase/4724047
Tea
(<i>Camellia sinensis</i>) is an important commercial
crop, in which the high content of flavonoids provides health benefits.
A flavonoid glycosyltransferase (CsUGT73A20), belonging to cluster
IIIa, was isolated from tea plant. The recombinant CsUGT73A20 in <i>Escherichia coli</i> exhibited a broad substrate tolerance toward
multiple flavonoids. Among them, kaempferol was the optimal substrate
compared to quercetin, myricetin, naringenin, apigenin, and kaempferide.
However, no product was detected when UDP-galactose was used as the
sugar donor. The reaction assay indicated that rCsUGT73A20 performed
multisite glycosidation toward flavonol compounds, mainly forming
3-<i>O</i>-glucoside and 7-<i>O</i>-glucoside
in vitro. The biochemical characterization analysis of CsUGT73A20
showed more K7G product accumulated at pH 8.0, but K3G was the main
product at pH 9.0. Kinetic analysis demonstrated that high pH repressed
the glycosylation reaction at the 7-OH site in vitro. Besides, the
content of five flavonol-glucosides was increased in CsUGT73A20-overexpressing
tobaccos (<i>Nicotiana tabacum</i>).
2017-02-21 00:00:00
substrate
glucoside
Camellia sinensis
3G
CsUGT 73A
content
K 7G product
flavonoid
7- OH site
Flavonoid Glycosyltransferase Tea
CsUGT 73A tobaccos
pH 9.0. Kinetic analysis