VP2 S-P Soluble Protein Of IBDV NB Strain Expressed By SUMO System

Avian infectious bursal disease virus(Infectious Bursal Disease Virus,IBDV)causes immune suppression in the body.VP2 is the structural protein of IBDV,having the main protective antigen sites.The Shell domain and Projection domain are located in the extracellular and transmembrane regions of IBDV VP2 protein,containing the major antigenic sites of VP2.In the previous study,polypeptides that could bind to IBDV were screened in the Shell domain.Therefore,we used PCR to amplify the Shell domain and Projection domain genes,and constructed an efficient expression system of SUMO system,and induced the expression to get soluble fusion protein of VP2 Shell domain and Projection domain.The recombinant fusion protein was purified by Ni-NTA affinity chromatography(Ni-NTA).The objective protein removed the SUMO protein tag by SUMO proteinase I and purified by Ni-NTA again,then the target protein with higher purity was obtained.SDS-PAGE,Western blotting,and IBDV monoclonal antibody strips were used to detect recombinant fusion proteins and recombinant proteins.Results show as follows: IBDV VP2 S-P protein gene with the length of 1035 bp was amplified.The recombinant fusion protein,which is consistent with the expected protein size of 50 KDa,can bind specifically to His monoclonal antibody and IBDV hyperimmune serum,was named as SUMO-VP2 S-P.Under the condition of 28?,with IPTG as the inductor on the concentration of 0.5 mM induced for 6 h,the recombinant fusion protein was soluble expressed.The recombinant protein,which can bind to IBDV hyperimmune serum and detected as positive by the BDV monoclonal antibody test strip,was designated as VP2 S-P.Conclusion: IBDV VP2 S-P soluble protein was obtained by using SUMO fusion system,which laid the foundation for the later establishment of IBDV immunologic detection method.