1987 Volume 37 Issue 1 Pages 111-120
Analysis was made of hepatitis B virus surfaceantigen (yHBsAg) expressed in a systen using yeastas host by recombinant genetic techniques. They HBsAg was found to have been produced as a par-tide mainly composed of disulfied-bonded dimers of polypeptides each having a molecular weight of about 23, 000, in which the polypeptide corresponds to the polypeptide of human carrier's plasma-derived hepatitis B surface antigen (hHBsAg) without having glycosylated side-chain thereto. There were strong indications that such dimers are primarily responsible for antigenicity and immunogenicity, and that the steric structures of the yHBsAg due to disulfide bonds are related to the antigenicity and the immunogenicity. The N-terminml amino acid sequence and the amino acid composition of the yHBsAg were found to be in good agreement with those predicted from the DNA sequence. Other properties of the yHBsAg, such as CD spectrum, UV absorption spectrum and tryptic digestion pattern were quite similar to those of hHBsAg. Further, immunization experiments using mice and guinea pigs showed that the immunogenicity of the yHBsAg is equivalent to that of hHBsAg.
