丹参变应原基因(Sam a1)的克隆及其原核表达  

Cloning of An Allergen Gene(Sam a1) from Salvia miltiorrhiza Bunge and Its Prokaryotic Expression

作　　者：化文平[1] 王喆之[1] 

机构地区：[1]教育部药用植物资源与天然药物化学重点实验室陕西师范大学生命科学学院,西安710062

出　　处：《植物研究》2008年第5期574-578,共5页Bulletin of Botanical Research

基　　金：国家"十一五"科技支撑计划(2006BAI06A12-04)

摘　　要：Ⅰ型变态反应是小分子植物蛋白结合IgE抗体引起的一种疾病。本文首次从丹参中克隆出变应原蛋白基因，命名为：Sam a1（GenBank注册号：EU122383）。Sama1包含483bp的开放读码框，编码160个氨基酸残基。其推导氨基酸（命名为：Sama1）具有Bet v1结构域，属于病原菌相关的Bet v1蛋白家族，与苹果中变应原mal d1类似蛋白同源性高达66％。三级结构预测模型显示Sam a1含有T细胞主要抗原决定簇的c端仅螺旋。实时定量PCR结果显示：黄瓜细菌性角斑病茵和NaCl溶液诱导下Sam a1的表达呈现上调趋势，表明Sam a1可能与病程相关蛋白和盐胁迫相关。Sam a1转入大肠杆菌M15后，表达出与预测蛋白大小相当的目标蛋白，IPTG诱导后5～7h目标蛋白可大量表达。本研究为从植物分子机制上了解中药变态反应作用机制奠定了基础，尤其对中药产业的发展具有重要的意义。Type [ allergic reaction results from the cross-binding of major allergen protein and IgE antibodies. A novel allergen gene （ Sam a 1 ） from Salvia miltiorrhiza Bunge was cloned, which contained an ORF with 483 bp and coded 166 amino acid residues. It contained a Bet vl protein domain, shared 66% identical to mal d1-a major allergen protein from apple. The 3-D model suggested the deduced protein contained an extended C-terminal alpha helix containing a major T cell epitope. The real time PCR results indicated Sam a 1 was induced by PSL and NaC1, Sam a 1 may be involved in pathogenesis infec- tion and stress by NaC1. The gene was expressed in E. coli M15, and a target protein was obtained. In addition, the recombinant protein was expressed in large quantities after 5 - 7 h induced by IPTG. This research laid the groundwork for the study of allergic reaction mechanism in plant at molecular level, especially for the development of Chinese herb medicine.

关 键 词：变应原 基因克隆 REAL time PCR 表达载体 

分 类 号：Q943.2[生物学—植物学]