[Construction and characterization of hepatitis B surface antigen "a" epitope virus-like particles].

Objective: To construct virus-like particles of hepatitis B core antigen, with HBsAg "a" epitope exposed on the surface.

Methods: Hepatitis B surface antigen "a" epitope were inserted into the Hepatitis B core antigen, between the 78th (Asp) and the 79th (Pro) amino acids. The gene was synthesized after the codon optimized, then it was ligated to the express vector after been enzyme digest. The virus-like particles were observed by electron microscope and detected by ELISA after been expressed and purified. Immune the rabbits by the VLPs, then detect the antibody.

Result: The virus-like particles were confirmed by electron microscope. Its antigenicity and immunogenicity were identified by ELISA.

Conclusion: The prokaryotic express plasmid with the fusion gene has been constructed successfully. The virus-like particles have been expressed, purified and identified, which lays the foundation for its application in the further.