The invention relates to a vector used for displaying antigenic
epitope by using
hepatitis B
virus core particles, an animal vaccine, and a preparation method thereof. According to the invention,
a DNA artificial synthesis method is adopted, and a coding
DNA sequence of
amino acid necessary for
hepatitis B
virus core protein is synthesized. In the synthesis process, a coding
DNA sequence of
hepatitis B
virus core protein true
peptide 1-149 site
amino acid is adopted as a framework; 79-82 site
amino acid coding sequence in the framework is removed, and only coding
DNA relevant to virus particle
assembly is preserved; for facilitating the
insertion of other antigenic proteins in the
hepatitis B virus
core particle protein, a segment of DNA sequence coding flexible
peptide is specially inserted at a position of the 79-82 site amino acid, and three
endonuclease sites are introduced into the sequence, such that
gene operation is facilitated; the above synthesized DNA segment is cloned into a
gene cloning vector pUC18, such that a special vector pZNVC used for displaying antigenic
epitope is formed; a synthesized DNA segment of an
antigenic protein gene or coding
epitope is inserted into pZNVC, and
fusion protein is expressed in prokaryotic organisms or eukaryotic organisms. 78 amino acids on N-end of
hepatitis B virus and 68 amino acids on C-end of
hepatitis B virus can be folded into two columnar bodies, such that building blocks used for assembling the
core protein particle are formed; flexible
peptide forms a bond connecting the two columnar bodies; and proteins inserted between the flexible peptide protrude on the surface of the viral particles. The flexible peptide is composed of a series of small amino acids without
side chain, and has certain flexibility. The flexible peptide does not affect the
hepatitis B virus core particle protein and
antigenic protein in independently and respectively folding into natural molecular structures. pZNVC is used for displaying
antigenic protein antigenic epitopes, such that the existence state of the antigenic epitopes on natural
pathogen outer membrane can be simulated to a maximal extent.