This invention provides an isolated strain of Hepatitis B virus designated
Human Hepatitis B Virus Surface Antigen-`S`-133 Oon Strain (Methionine to
Threonine) which constituent viral genome is deposited under Accession
Nos. P97121501, P97121502 and P97121503 with the European Collection of
Cell Culture on 15.sup.th December 1997. This invention also provides an
isolated nucleic acid encoding a polypeptide which is a mutant major
surface antigen of a strain of hepatitis B virus, such polypeptide having
an amino acid sequence which differs from the amino acid sequence of a
major surface antigen of a wild type hepatitis B virus in that the amino
acid at position number 133 of such polypeptide is a threonine rather than
a methionine. This invention also provides an isolated nucleic acid which
encodes a peptide, wherein the peptide is encoded by a nucleic acid
molecule comprising nucleotides 527 through 595 of SEQ. I.D. No. 1 and the
purified peptide. This invention also provides various methods of using
the disclosed isolated nucleic acid and peptides.
