A hepatitis B surface antigen polypeptide (P31) with the receptor for polymerized human as well as chimpanzee albumins.

Hepatitis B virus, and hepatitis B surface antigen particles co-occurring with hepatitis B e antigen, have the receptor for polymerized human and chimpanzee albumins that may be involved in the hepatotropism of hepatitis B virus. We identified the receptor on a hepatitis B surface antigen polypeptide with a molecular size of 31,000 daltons (P31). P31 bound to polymerized albumins from human and chimpanzee, but did not react with polymerized albumins from the experimental animals without susceptibility to hepatitis B virus. P31 was composed of the major polypeptide of hepatitis B surface antigen with a molecular size of approximately 22,000 daltons (P22) and additional 55 amino acid residues coded by the pre-S region in the hepatitis B virus-specific deoxyribonucleic acid. Because P22 did not react with polymerized albumin, the sequence of 55 amino acid residues in the pre-S region appeared to bear the receptor. Polypeptides with the receptor for polymerized albumin may make an efficacious hepatitis B vaccine, because they could raise antibodies against the putative site on hepatitis B virus capable of binding with hepatocytes to initiate the infection.