猫重组变应原Fel d 1 与乙肝病毒核心抗原融合基因的原核表达

摘要

为将猫重组变应原Fel d 1蛋白展示在乙肝病毒核心抗原(HBcAg)病毒样颗粒的表面,本试验将编码Fel d 1蛋白的两个基因chain 1和chain 2 拼接在一起形成重组Fel d 1(rFel d 1),然后插入到HBcAg的c/e1 loop区,取代HBcAg c/e1 loop 区的D78与E83之间的氨基酸.经密码子优化后进行全基因合成,成功构建了pET28a-HBcAg-rFel d 1原核表达载体,将其转化入大肠杆菌BL21(DE3)中,进行原核诱导表达与Ni-NTA亲和层析纯化,并进行SDS-PAGE电泳、Western blotting和透射电镜检测.结果显示,本试验成功表达了HBcAg-rFel d 1融合蛋白,并利用镍柱纯化得到了较纯的HBcAg-rFel d 1融合蛋白,进一步利用负染法透射电子显微镜检测到HBcAg-rFel d 1融合蛋白呈现病毒样颗粒结构.HBcAg-rFel d 1融合蛋白能自发形成病毒样颗粒结构,为猫过敏症的预防与治疗性疫苗的开发奠定基础.%To expose the cat recombinant allergen Fel d 1 protein on the outer surface of hepatitis B core antigen (HBcAg) virus-like particles (VLPs), the recombinant Fel d 1 (rFel d 1) was created by linking the two genes chain 1 and chain 2 that composed the Fel d 1 protein.Then the rFel d 1 sequence was inserted into the HBcAg c/e1 loop area, replacing the amino acids between D78 and E83 in HBcAg c/e1 loop area.We successfully constructed the prokaryotic expression vector pET28a-HBcAg-rFel d 1 via gene codon optimization and synthesis.The recombinant plasmid pET28a-HBcAg-rFel d 1 was transformed into E.coli BL21(DE3) cells, then induced by IPTG, purified by Ni-NTA affinity chromatography and tested by SDS-PAGE, Western blotting and transmission electron microscopy (TEM).The fusion protein HBcAg-rFel d 1 was expressed successfully in E.coli expression system and the pure fusion protein HBcAg-rFel d 1 was purified by Ni-NTA affinity chromatography.Further, TEM confirmed the fusion protein HBcAg-rFel d 1 could assemble into VLPs.The fusion protein HBcAg-rFel d 1 could assemble into VLPs spontaneously, which laid a solid foundation for the research of the preventive and therapeutic vaccines for cat allergy.