Objective  In order to determine the function of SU protein of enzootic nasal tumor virus of goats (ENTV-2),

  Method  RT-PCR method was used to amplify the SU gene fragment from ENTV-2 FJ and then the SU gene was cloned into pMD-19T Simple Vector; After sequencing, the cloning vector was subcloned into PET-32a (+), the recombinant plasmid was transformed into RosettagamiB (DE3) competent cells. SDS-PAGE, Western-blot and ELISA were used for identification and antigenicity analysis of recombinant proteins.

  Result  The result showed that the expressed recombinant protein was about 64.38 kD, and the best expression condition was induced at 37 ℃ for 4 h at a final IPTG concentration of 0.4 mmol/L. The purified ENTV-2 virus was used for SDS-PAGE, and the mice anti-SU polyclonal antibody was used as primary antibody for Western-blot. The Western-blot analysis showed the mice anti-SU polyclonal antibody could react with ENTV-2 antigen specifically. It is proved that the expressed SU recombinant protein has better antigenicity.

  Conclusion  The results proved that the expressed SU recombinant protein has better antigenicity, and provided a basis for the preparation of ENTV-2 specific monoclonal antibody and the establishment of ENTV-2 specific serological method.