Expression of predicted B cell epitope peptide in S2 subunit of SARS coronavirus spike protein in E.coli and identification of its mimic antigenicity

    FENG Yu, WAN Min, WANG Xuanª²jun, ZHANG Peiª²yin, YU Yongª²li, WANG Liª²ying*

    Department of Molecular Biology, Department of Immunology, Basic Medical College, Jilin University, Changchun 130021, China

    [Abstract] AIM: To study the expression of predicted B cell epitope peptide in S2 subunit of SARS coronavirus spike protein in E.coli and its mimic antigenicity to S2 protein. METHODS: B cell epitopes in S2 subunit of SARS coronavirus spike protein was predicted using DNAStar software. The cDNA sequence encoding the B cell epitope peptide was constructed artificially by PCR and then cloned into the downstream of chaperone 10 gene in vector pET28a(+) to construct pET28ª²chap10ª²S2epi plasmid. The fusion protein, chap10ª²S2epi, was expressed in E.coli BL21(DE3) and identified by SDSª²PAGE and Western blot. The rabbit was immunized by purified Chap10ª²S2epi for the preparation of antiserum, which was used to identify the mimic antigenicity of Chap10ª²S2epi to S2 protein by ELISA. RESULTS: Chap10ª²S2epi fusion protein was successfully constructed and expressed in E.coli. The antiserum from the animal immunized by Chap10ª²S2epi recognized full length of SARS coronavirus S2 spike protein. CONCLUSION: The predicted B cell epitope peptide of SARS coronavirus S2 spike protein can induce the antigenicity of S2 protein, which provides some fundamental data for developing engineering vaccine against SARS coronavirus infection. ......