猪源大肠杆菌志贺样毒素2型突变体B亚基与LTB基因的融合与表达  

The fusion and expression of genes encoding subunit B of Shiga-like toxin type 2 variant and subunit B of Escherichia coli heat-labile enterotoxins from porcine origin

作　　者：王红珍[1] 冉雪琴[1] 吴拥军[1] 王嘉福[1] 

机构地区：[1]贵州大学动物科学学院/农业工程省级重点实验室

出　　处：《西南农业学报》2007年第6期1324-1328,共5页Southwest China Journal of Agricultural Sciences

基　　金：国家自然科学基金(30560104);国家教育部骨干教师基金(教技司2000-65);贵州省优秀青年科技人才培养计划(2002-0203);贵州省"十一五"农业科技重大专项(2005NZ3002)

摘　　要：猪水肿病的主要毒力因子是志贺样毒素的2型突变体(Stx2e),毒素的A亚基是有毒的酶活性单位,B亚基无毒,介导毒素与受体的结合。为了增加B亚基的免疫原性,采用重叠PCR将猪源志贺样毒素Ⅱ型突变体B亚单位(Stx2e B)连接至热敏肠毒素的B亚单位(LTB)成熟肽N末端,获得Stx2e B与LTB相连的融合蛋白基因Stx2e B-LTB。融合基因克隆到表达载体pQE30中,在IPTG的诱导下,融合基因在大肠杆菌中获得表达,表达量占细菌总蛋白的8%。融合蛋白的获得为猪水肿病基因工程亚单位疫苗的制备、猪水肿病的预防奠定了基础。To augment the immunogenicity of subunit B of Shiga toxin 2 （Stx2e B） isolated from piglet with edema disease, the nucleotides fragment coding for the matured peptide of Stx2e B was fused to the 5 ＇-terminus of the gene coding the heat labile enterotoxin chain B （ LTB ） by overlap PCR. The fusion gene of stx2e B-LTB was correctly constructed into vector pQE30. The fusion protein with molecular weight of a- bout 20.7 Kd was successfully expressed in E. coli M15 and confirmed by SDS-PAGE. The Stx2e B of the fusion protein could be specifically recognized by Stx2e antibody. Genetically constructed chimeric proteins exhibiting Stx2e B and LTB antigens on the same molecule may supply a promising approach to development of broadly protective immunoprophylactic vaccine for edema and diarrhea diseases caused by EHEC and ETEC in pig.

关 键 词：猪 大肠杆菌 志贺样毒素2型突变体 热敏肠毒素 基因融合 

分 类 号：S852.1[农业科学—基础兽医学]