Antigenic properties of the pre-S(2) region of the hepatitis B virus surface antigen against anti-HBsAg mouse polyclonal antibodies

Abstract

An社genic properties of the pre-S(2) region of the hepatitis B virus surface antigen (HBsAg) were studied using anti-HBsAg mouse polyclonal antisera and synthetic peptides. The polyclonal antibodies showed a preference for the adr subtype (immunogen subtype) regardless of adjuvant used, and recognized mainly continuous epitopes in the area covered by the sequence 130 to 145. The importance of each residue in the sequence was studied using substituted peptides. The N-terminal and/or middle region in the sequence 130 to 145, especially positively charged arginine residues at positions 135 and 137, seemed to play a more important role in the binding of the polyclonal antibodies than the C-terminal region. However, Pro134 located in the N-terminal region, did not affect antigenicity when compared with the residues 130 to 133 and Arg135, indicating that the antibodies responsive to this region may only recognize the backbone structure of proline.