According to the data concerned and with the aids of DNA star software,the 250-460 amino acids of the glycoprotein B of Marek’s disease virus GA strain was selected as target fragment for tandem expression.Two pairs ...According to the data concerned and with the aids of DNA star software,the 250-460 amino acids of the glycoprotein B of Marek’s disease virus GA strain was selected as target fragment for tandem expression.Two pairs of primers were designed for amplifying the upstream fragment gB(U) and the downstream fragment gB(L/D).And an ATG GCG was added to the 5’ terminus of gB(U),a TAA was added to the 3’ terminus of gB(L/D) and a linker of nine amino acids was designed at the 5’ terminus of gB(L/D).Thus a complete ORF formed when gB(U) contacted with gB(L/D).PCR products were cloned by general molecular clone method.A transfer plasmid vector pEFMDgB(U/L/D) was constructed and then cotransfected with fowl poxvirus in CEF by calcium phosphate method and the recombinant virus was selected with MPA and its specificity was identified positive in infected CEF.The result showed that the tandem expressing products have immunocompetence,and this will bring a prospect for developing a candidate MD vaccine.展开更多
根据猪链球菌2型(Streptococcus suis type 2,SS2)溶菌酶释放蛋白(muramidase-released protein,MRP)和胞外蛋白因子(extracellular protein factor,EPF)的基因序列,各设计合成一对引物,以猪链球菌2型江苏分离株SS2-1的基因组为模板,扩...根据猪链球菌2型(Streptococcus suis type 2,SS2)溶菌酶释放蛋白(muramidase-released protein,MRP)和胞外蛋白因子(extracellular protein factor,EPF)的基因序列,各设计合成一对引物,以猪链球菌2型江苏分离株SS2-1的基因组为模板,扩增mrp基因1 801~2 513位序列和epf 基因1 783~2 563位序列,分别构建原核表达载体pET32a-mrp 、pET32a-epf,确定诱导表达的两种蛋白都具有免疫原性后,提取阳性克隆质粒各自进行双酶切并纯化,通过PCR串联两片段,将目的片段定向克隆到表达载体pET-32a中,重组质粒转化入大肠杆菌BL21,经IPTG诱导表达分子量约为74kD的融合蛋白.用制备的两种抗血清与纯化融合蛋白进行免疫转印,结果显示融合蛋白分别具有MRP与EPF的中和表位.用融合蛋白MRP-EPF免疫新西兰兔,以最小致死量猪链球菌强毒株SS2-1攻击,兔的存活率达50%(2/4),存活率明显高于单个表达产物.证实串联表达的融合蛋白为重要的保护性抗原.展开更多
文摘According to the data concerned and with the aids of DNA star software,the 250-460 amino acids of the glycoprotein B of Marek’s disease virus GA strain was selected as target fragment for tandem expression.Two pairs of primers were designed for amplifying the upstream fragment gB(U) and the downstream fragment gB(L/D).And an ATG GCG was added to the 5’ terminus of gB(U),a TAA was added to the 3’ terminus of gB(L/D) and a linker of nine amino acids was designed at the 5’ terminus of gB(L/D).Thus a complete ORF formed when gB(U) contacted with gB(L/D).PCR products were cloned by general molecular clone method.A transfer plasmid vector pEFMDgB(U/L/D) was constructed and then cotransfected with fowl poxvirus in CEF by calcium phosphate method and the recombinant virus was selected with MPA and its specificity was identified positive in infected CEF.The result showed that the tandem expressing products have immunocompetence,and this will bring a prospect for developing a candidate MD vaccine.
文摘根据猪链球菌2型(Streptococcus suis type 2,SS2)溶菌酶释放蛋白(muramidase-released protein,MRP)和胞外蛋白因子(extracellular protein factor,EPF)的基因序列,各设计合成一对引物,以猪链球菌2型江苏分离株SS2-1的基因组为模板,扩增mrp基因1 801~2 513位序列和epf 基因1 783~2 563位序列,分别构建原核表达载体pET32a-mrp 、pET32a-epf,确定诱导表达的两种蛋白都具有免疫原性后,提取阳性克隆质粒各自进行双酶切并纯化,通过PCR串联两片段,将目的片段定向克隆到表达载体pET-32a中,重组质粒转化入大肠杆菌BL21,经IPTG诱导表达分子量约为74kD的融合蛋白.用制备的两种抗血清与纯化融合蛋白进行免疫转印,结果显示融合蛋白分别具有MRP与EPF的中和表位.用融合蛋白MRP-EPF免疫新西兰兔,以最小致死量猪链球菌强毒株SS2-1攻击,兔的存活率达50%(2/4),存活率明显高于单个表达产物.证实串联表达的融合蛋白为重要的保护性抗原.
