Premium
Labeling of hepatitis B virus surface antigen (HBsAg) synthesized in a HBsAg‐producing hepatoma cell line
Author(s) -
Hofschneider Peter Hans,
Zaslavsky Vladimir,
Deinhardt Friedrich,
Frösner Gert G.,
Alexander Jennifer J.
Publication year - 1979
Publication title -
journal of medical virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 121
eISSN - 1096-9071
pISSN - 0146-6615
DOI - 10.1002/jmv.1890040303
Subject(s) - hbsag , cystine , hbeag , methionine , hepatitis b virus , sodium dodecyl sulfate , chemistry , hbcag , differential centrifugation , biochemistry , microbiology and biotechnology , centrifugation , antigen , cell culture , virology , biology , virus , amino acid , cysteine , enzyme , immunology , genetics
Hepatitis B virus surface antigen (HBsAg) could be studied until recently only by isolating it from the blood of carriers, thus making incorporation of radioactive precursors into this protein(s) impossible. The isolation of a cell line producing HBsAg [Alexander et al, 1978] has eliminated this obstacle. The cell line was therefore used for labeling HBsAg either with 35 S‐methionine or with 35 S‐cystine. HBsAg was purified by pelleting the component and by isopycnic centrifugation in CsCI gradients. HBsAg‐positive fractions (as determined by solid‐phase radioimmunoassay) were isolated from the gradients and analyzed in sodium dodecyl sulfate‐containing polyacrylamide gels. It was found that although HBsAg contains substantial amounts of 35 S‐cystine, very little 35 S‐methionine was incorporated into this protein. In contrast, both labels were found in other structures having a buoyant density of about 1.3 gm/cm 3 in CsCI. It was concluded that HBsAg is very low in methionine, and therefore this amino acid should not be used for labeling HBsAg in cells or in a cell‐free system. Analysis of 35 S‐cystine‐labeled HBsAg‐positive material (buoyant density about 1.2 gm/cm 3 in CsCI) revealed five proteins with molecular weights in the range of 48,000–82,000.