Expression and identification of truncated GB protein of bovine rhinotracheitis virus.

The total IBRV gB gene was amplified by PCR and connected to the cloning vector pMD18-T.It was named pMD18-T-gB.Four pairs of primers for amplification antigenic sites were designed and synthesized in accordance with DNAstar biology software based on the IBRV Bartha Nu/67 gB gene published on GenBank.EcoRⅠand SalⅠwere inse ted in primers.Four antigenic sites were amplified using recombinant pMD18-T-gB as a template,fragments of four antigenic sites gene were connected to the pMD18-T cloning vector and expression vector pGEX-6p-1.Recombinant expression plasmids were induced by IPTG and successful expression of the four recombinant proteins.The results of SDS-PAGE electrophoresis showed that the four target fusion proteins mainly existed in the form of inclusion bodies,with its size of 40 300,39 000,38 700 and 37 800 approximately.All of four recombinant proteins were purified by using GSTrap HP chromatography and identified using the methods of Western blot and indirect ELISA.The gB3 and gB4 recombinant proteins had better antigenic reactivity and specificity.