甘草HMGR基因cDNA的克隆及功能鉴定(英文)  

Cloning and characterization of a cDNA coding 3-hydroxy-3-methylglutary CoA reductase involved in glycyrrhizic acid biosynthesis in Glycyrrhiza uralensis

作　　者：刘颖[1] 许巧仙[1] 席培宇[1] 陈宏昊[1] 刘春生[1] 

机构地区：[1]北京中医药大学中药学院,北京100102

出　　处：《药学学报》2013年第5期773-779,共7页Acta Pharmaceutica Sinica

基　　金：Project supported by the National Natural Science Foundation(81072988)

摘　　要：甘草为常用中药材,具有补脾益气、清热解毒、祛痰止咳、缓急止痛和调和诸药等作用。甘草酸是甘草中的主要活性成分,其生物合成途径受到许多酶的调控,其中3-羟基-3-甲基戊二酰CoA还原酶(3-hydroxy-3-methylglutary CoA reductase,HMGR)催化3-羟基-3-甲基戊二酰辅酶A(3-hydroxy-3-methylglutary CoA,HMG-CoA)生成甲羟戊酸(MVA),是该途径中的第一个限速酶。本文克隆了甘草HMGR基因cDNA序列,对其进行序列分析,并与其他物种进行序列比对。构建了原核表达载体,诱导其外源表达及酶促反应,并利用TLC及GC-MS对产物进行检测。结果表明本文克隆得到的HMGR序列能很好的完成特定的酶促反应任务。由于HMGR基因在甘草酸生物合成途径中的重要作用,因此本实验的研究结果对于在分子水平上揭示高品质甘草的形成机制具有一定的意义。The roots of Glycyrrhiza uralensis are widely used in Chinese medicine for their action of clearing heat, detoxicating, relieving cough, dispelling sputum and tonifying spleen and stomach. The reason why Glycyrrhiza uralensis has potent and significant actions is that it contains various active secondary metabolites, especially glycyrrhizic acid. In the present study, we cloned the eDNA coding 3-hydroxy-3-methylglutary CoA reductase （HMGR） involved in glycyrrhizic acid biosynthesis in Glycyrrhiza uralensis. The corresponding eDNA was expressed in Escherichia coli as fusion proteins. Recombinant HMGR exhibited catalysis activity in reduction of HMG-CoA to mevalonic acid （MVA） just as HMGR isolated from other species. Because HMGR gene is very important in the biosynthesis of glycyrrhizic acid in Glycyrrhiza uralensis, this work is significant for further studies concerned with strengthening the efficacy of Glycyrrhiza uralensis by means of increasing glyeyrrhizic acid content and exploring the biosynthesis of glycyrrhizic acid in vitro.

关 键 词：甘草 HMGR CDNA 原核表达 GC MS 

分 类 号：R931[医药卫生—生药学]