口蹄疫病毒VP2基因的原核表达及抗原性检测

将口蹄疫病毒VP2基因连接到原核表达载体pPROEX^TM HTb上，获得重组质粒pPR-VP2。将此质粒转化感受态菌DH5α中，经终浓度为1．0mmol／L的IPTG诱导，1h～6h依次收集菌液，SDS-PAGE电泳分析，在4h后表达量可达到高峰。经过软件分析，表达产物占总菌体蛋白的23．1％，大小为33Ku左右。根据Ni-NTA纯化系统说明操作，获得较纯的VP2融合蛋白。以牛抗O型口蹄疫病毒血清为第一抗体，通过Western blot和Dot ELISA鉴定，纯化后的VP2融合蛋白可以与牛抗O型口蹄疫病毒血清发生特异性反应。

Prokaryotic expression and antigenicity characterization of foot-and-mouth disease virus VP2 gene

A recombinant expression vector pPROEX^TM HTb-VP2 was constructed by cloning VP2 gene of foot-and-mouth disease virus into the prokaryotic expression plasmid pPROEX^TM HTb. The vector was transformed into the E.coli DH5.6 strain and samples of bacteria cultures were collected at different time points after IFTG induction. Expression and specificity of the fusion protein was determined by SDS-PAGE and Western blot analysis. The results showed that optimal protein expression, which accounts for 23.1% of total bacterial protein, could be achieved after being induced with IPTG at 1.0 mmol/L concentration for 4 hours. The fusion protein is 33 Ku in size and exhibited specific reaction with VP2 specific antibodies. The fusion protein was purified using a Ni-NTA purification system. Antigenicity of the purified fusion protein was authenticated through Western blot and Dot ELISA using cattle antisera as first antibody.