Identification and characterization of camptothecin tailoring enzymes in Nothapodytes tomentosa  

作　　者：Yin Chen Jian-Ping Huang Yong-Jiang Wang Meng-Ling Tu Junheng Li Bingyan Xu Guoqing Peng Jing Yang Sheng-Xiong Huang 

机构地区：[1]State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry,Kunming Institute of Botany,Chinese Academy of Sciences,Kunming 650201,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory for Economic Plants and Biotechnology,Kunming Institute of Botany,Chinese Academy of Sciences,Kunming 650201,China

出　　处：《Journal of Integrative Plant Biology》2024年第6期1158-1169,共12页植物学报（英文版）

基　　金：supported by National Natural Science Foundation of China(82225043);Biological Resources Program(KFJBRP-009);Yunnan Revitalization Talent Support Program“Yunling Scholar”Project(S.-X.H.);Yunnan Revitalization Talent Support Program“Young Talent”Project(J.-P.H.)。

摘　　要：Camptothecin is a complex monoterpenoid indole alkaloid with remarkable antitumor activity.Given that two C-10 modified camptothecin derivatives,topotecan and irinotecan,have been approved as potent anticancer agents,there is a critical need for methods to access other aromatic ringfunctionalized congeners(e.g.,C-9,C-10,etc.).However,contemporary methods for chemical oxidation are generally harsh and low-yielding when applied to the camptothecin scaffold,thereby limiting the development of modified derivatives.Reported herein,we have identified four tailoring enzymes responsible for C-9 modifications of camptothecin from Nothapodytes tomentosa,via metabolomic and transcriptomic analysis.These consist of a cytochrome P450(Nt CPT9H)which catalyzes the regioselective oxidation of camptothecin to 9-hydroxycamptothecin,as well as two methyltransferases(Nt OMT1/2,converting 9-hydroxycamptothecin to 9-methoxycamptothecin),and a uridine diphosphate-glycosyltransferase(Nt UGT5,decorating 9-hydroxycamptothecin to9-β-D-glucosyloxycamptothecin).Importantly,the critical residues that contribute to the specific catalytic activity of Nt CPT9H have been elucidated through molecular docking and mutagenesis experiments.This work provides a genetic basis for producing camptothecin derivatives through metabolic engineering.This will hasten the discovery of novel C-9 modified camptothecin derivatives,with profound implications for pharmaceutical manufacture.

关 键 词：camptothecin biosynthesis enzymatic assay Nothapodytes tomentosa tailoring enzyme transcriptomic analysis 

分 类 号：S792.117[农业科学—林木遗传育种]