title: Biochemical and immunological characterization of the duck hepatitis B virus envelope proteins.
abstract: To examine the envelope proteins of duck hepatitis B virus (DHBV), which are encoded by the pre-S/S open reading frame of the viral genome, an antiserum was raised in rabbits against a fusion protein comprising most of the pre-S coding segment. By using this antiserum, viral particles could be precipitated from serum, and two pre-S proteins with molecular sizes of approximately 35 and 37 kilodaltons were detected in the sera and livers of DHBV-infected ducks after Western blotting and after biosynthetic labeling of a primary duck liver cell culture. In serum, the pre-S proteins were shown to exist predominantly in DHBV-DNA-free particles associated with a 17-kilodalton protein which, by N-terminal amino acid sequence analysis, was shown to represent the viral S protein which is encoded by the 3' proximal segment of the DHBV pre-S/S open reading frame. To compare the immunogenic potential of the S and pre-S proteins, serum particles and gel-purified S protein were used to immunize rabbits. In neither case was a significant immune response against the DHBV S protein observed. However, a good antibody titer against DHBV pre-S was obtained even after immunization with small amounts of the pre-S antigen.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000276:immunology; D004372:Ducks; D006515:Hepatitis B virus / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D006524:Hepatitis, Viral, Animal / Q000382:microbiology; D008099:Liver / Q000032:analysis; D011201:Poultry Diseases / Q000382:microbiology; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000956:Antigens, Viral; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins