[Construction of recombinant plasmid pYTA/Abeta-HBcAg and its expression in E.coli].

AIM

To study the expression of fusion gene Abeta-HBcAg in E.coli and detect the immunogenicity of fusion protein Abeta-HBcAg.

METHODS

The Abeta-HBcAg fusion gene was cut from recombinant plasmid pBV220/Abeta-HBcAg, and was inserted into the plasmid pYTA1 to construct recombinant plasmid pYTA/Abeta-HBcAg. The recombinant plasmid was transformed into E.coli DH5alpha, and expressed under IPTG induction. The expression of the fusion protein Abeta-HBcAg was detected by SDS-PAGE. The antigenicity of the fusion protein was detected by ELISA. BALB/c mice were immunized intraperitoneally with the fusion protein purified by salting out with saturate ammonium sulfate. The titers of anti- Abeta antibodies of the immunized mice was evaluated by ELISA.

RESULTS

Fusion protein existed in supernatant of the bacteria lysate and its expression level was about 7% of the total bacteria protein. The fusion protein reacted with both Abeta and HBcAg. The highest titer of anti-Abeta antibodies could reach to 1:16 000 after immunization for 3 times.

CONCLUSION

Recombinant gene Abeta-HBcAg can be expressed in E.coli DH5alpha. The expression protein exists in supernatant of the bacteria lysate and has good immunogenicity. This study lays the foundation for the experimental animal study of AD gene-engineering vaccine.