中国中药杂志2026，Vol.51Issue(8)：2211-2219,9.DOI:10.19540/j.cnki.cjcmm.20251204.401
粉葛O-糖基转移酶PtUGT-6和PtUGT-7的功能表征及酶学特性研究
Functional characterization and enzymatic properties of O-glycosyltransferases PtUGT-6 and PtUGT-7 in Pueraria thomsonii
摘要
Abstract
The dried root of Pueraria thomsonii,a plant of the Fabaceae family,features homology of medicine and food.It is rich in isoflavone glycosides such as puerarin and daidzin.Glycosylation,catalyzed by uridine diphosphate(UDP)glycosyltransferase(UGT),is a key post-modification step in isoflavone biosynthesis.However,the functional characterization of UGT in P.thomsonii remains limited.In this study,two putative O-glycosyltransferase genes,PtUGT-6 and PtUGT-7,were identified from the P.thomsonii transcriptome.Phylogenetic tree analysis revealed that PtUGT-6 and PtUGT-7 clustered closely with PlUGT15,an isoflavone 4',7-O-glycosyltransferase from P.lobata.In vitro enzymatic assays demonstrated that both PtUGT-6 and PtUGT-7 catalyzed the conversion of daidzein to daidzin.Enzymatic property analysis showed that the optimal reaction temperatures of PtUGT-6 and PtUGT-7 were 37 and 45℃,respectively,with an optimal pH of 9.0 for both enzymes.Furthermore,no metal ion dependence was exhibited.After 1 hour of the reaction,the substrate conversion rate reached approximately 80%and then tended to stabilize.Kinetic analysis revealed that the Km values of PtUGT-6 and PtUGT-7 were 22.43 and 29.39 μmol·L-1,respectively,with corresponding Kcat values of 2.16×10-3 and 2.17×10-3 s-1 and Kcat/Km of 96.30 and 73.83 L·mol-1·s-1,respectively.In summary,this study identified two glycosyltransferase genes,PtUGT-6 and PtUGT-7,from P.thomsonii,which can catalyze the glycosylation of daidzein to daidzin.These findings provide important insights into the biosynthetic pathway of characteristic isoflavone glycosides in P.thomsonii and offer a theoretical basis for improving the accumulation and quality of active compounds in this medicinal plant.关键词
粉葛/糖基转移酶/异黄酮/功能表征/生物合成Key words
Pueraria thomsonii/glycosyltransferase/isoflavone/functional characterization/biosynthesis引用本文复制引用
朱雨辰,刘为,姜振楠,袁媛..粉葛O-糖基转移酶PtUGT-6和PtUGT-7的功能表征及酶学特性研究[J].中国中药杂志,2026,51(8):2211-2219,9.基金项目
国家杰出青年科学基金项目(82325049) （82325049）
中国中医科学院科技创新工程项目(CI2023D001,CI2023E002-04) （CI2023D001,CI2023E002-04）
中央本级重大增减支项目(2060302) （2060302）
中央级公益性科研院所基本科研业务费专项(CZJJPY2025007) （CZJJPY2025007）
