Hepatitis delta virus: protein composition of delta antigen and its hepatitis B virus-derived envelope.
Hepatitis delta virus (HDV)-associated particles were purified from the serum of an experimentally infected chimpanzee by size chromatography and by density centrifugation. Hepatitis delta antigen (HDAg) was detected after mild detergent treatment at a column elution volume corresponding to 36-nm particles and banded at a density of 1.25 g/ml. The serum had an estimated titer of 10(9) to 10(10) HDV-associated particles and had only a 10-fold excess of hepatitis B surface antigen (HBsAg) not associated with HDAg. Therefore, HDV appears to be much more efficiently packed and secreted than is its helper virus, hepatitis B virus (HBV), which is usually accompanied by a 1,000-fold excess of HBsAg. The protein compositions of the HDAg-containing particles were analyzed by immunoblotting with HDAg-, HBsAg-, and hepatitis B core antigen-specific antisera and monoclonal antibodies to HBV surface gene products. The HBsAg envelope of HDAg contained approximately 95% P24/GP27s, 5% GP33/36s, and 1% P39/GP42s proteins. This protein composition was more similar to that of the 22-nm particles of HBsAg than to that of complete HBV. The significant amount of GP33/36s suggests that the HBsAg component of the HDV-associated particle carries the albumin receptor. Two proteins of 27 and 29 kilodaltons which specifically bound antibody to HDAg but not HBV-specific antibodies were detected in the interior of the 36-nm particle. Since these proteins were structural components of HDAg and were most likely coded for by HDV, they were designated P27d and P29d.
Bonino
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Heermann
K H
KH
Rizzetto
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M
Gerlich
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WH
D000818:Animals; D006511:Hepatitis B Antigens / Q000032:analysis* / Q000302:isolation & purification; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D003698:Hepatitis Delta Virus / Q000032:analysis*; D035923:Hepatitis delta Antigens; D007106:Immune Sera / Q000276:immunology; D002679:Pan troglodytes; D014759:Viral Envelope Proteins / Q000032:analysis* / Q000276:immunology
D006511:Hepatitis B Antigens; D006514:Hepatitis B Surface Antigens; D035923:Hepatitis delta Antigens; D007106:Immune Sera; D014759:Viral Envelope Proteins; C442244:hepatitis delta virus large antigen