title: Expression of hepatitis B virus surface antigen P31 gene in Escherichia coli.
abstract: A hepatitis B virus surface antigen (HBsAg) P31-coding DNA was constructed from a DNA fragment of the plasmid pHBr330 containing the entire hepatitis B virus (HBV) adr DNA and a chemically synthesized adaptor. The P31 gene was inserted into an expression vector, pTRP771, having an Escherichia coli tryptophan operon (trp) promoter to give a recombinant plasmid pTRP P31-R. The distance between the Shine-Dalgarno (SD) sequence and the initiation codon of P31 gene was adjusted to 9 bp. The expression level of HBsAg by E. coli 294[pTRP P31-R] was significantly elevated, in contrast to that of HBsAg by E. coli 294[pTRP SS-6]. Western blotting analysis has shown that E. coli[pTRP P31-R] synthesizes a specific polypeptide P31 of about 31 kDal, which reacts with anti-HBsAg antibody. The binding studies with polyalbumins from various species have also suggested that HBsAg P31 specifically binds to polymerized human serum albumin.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics*; D005822:Genetic Vectors; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D006801:Humans; D010957:Plasmids; D012709:Serum Albumin / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D006514:Hepatitis B Surface Antigens; D012709:Serum Albumin; D004262:DNA Restriction Enzymes