Prokaryotic Expression of Nucleoprotein Gene of Mouse Hepatitis Virus and Analysis of Its Immunological Activity

Nucleoprotein(N) gene of mouse hepatitis virus strain A59(MHV-A59) was cloned,expressed and the immunological activity of the recombinant protein was analyzed.According to N gene sequence of MHV-A59 published in GenBank,a pair of primers was designed to amplify a part of N gene of MHV-A59.The PCR product was purified and cloned to pGEM-T-easy.Using enzyme digestion and T4 ligase,the target gene was further subcloned to prokaryotic expressing vector pGEX-6p-1 and after transfected into transformed E.coli strain BL21,it was induced by IPTG to express recombinant protein.The recombinant protein was identified by SDS-PAGE and Western-blot analysis.The result revealed that the protein had a molecular weight of 56×10~3,which could be specifically recognized by anti-MHV antibody.Because of its good immunogenicity,the recombinant protein can be used as an antigen to detect anti-MHV antibody in sera of mice in ELISA.