N端融合外源蛋白的兔出血症病毒衣壳蛋白自聚能力的研究

将兔出血症病毒衣壳蛋白VP6 0基因插入杆状病毒转移载体pBLUEBACHIS2_B的 6 HIS表达标签下游 ,与线性化野生型杆状病毒基因组DNA共转染Sf9昆虫细胞 ,经蚀斑纯化后获克隆化重组杆状病毒pBLUEBACHIS2B_VP6 0。以重组杆状病毒感染Sf9细胞 ,经SDS_PAGE和Westernblot检测显示高效表达一分子量为 6 9kD的重组蛋白 ,并且该蛋白可被兔抗RHDV高免血清识别。血凝试验表明 ,该重组蛋白可以凝集人“O”型红细胞 ,血凝价达 2 1 6 ,同时 ,该血凝性可被抗RHDV的高免血清所抑制。经电镜观察 ,重组病毒表达的融合有 6 HIS表达标签的衣壳蛋白仍可在昆虫细胞内自聚成不包裹核酸的、与天然RHDV病毒粒子在物理形态上相似的病毒样颗粒 (VLPs) ,并且该VLPs与兔抗RHDV高免血清作用后于电镜下可见凝集成团的现象 ,表明其与天然RHDV病毒粒子在抗原性上也极为相似

Study on the self-assemble ability of expressed capsid protein of Rabbit haemorrhagic disease virus that fused with foreign epitope at the N-terminus

The RHDV capsid protein (VP60) gene was first subcloned into the transfer plasmid pBLUEBACHIS2B located downstream of a 6*HIS tag, then the recombinant transfer plasmid DNA were cotransfected Sf 9 cells with Bac-N-Blue DNA and purified for cloned recombinant baculovirus by plaque assay. The expression of fused-VP60 gene was analyzed by SDS-PAGE and Western blot. A specific 69 kD protein band was obtained. Observed under electron micrography, the recombinant baulovirus expressed VP60 protein assembled into viruslike particles which were morphologically and antigenically similar to native RHD virus but did not package RNA. The close-to-native conformation of the VLPs was also supported by the haemagglutination test, in which recombinant VLPs, like RHDV, agglutinated human blood type O erythrocytes.