Australia Antigen (Hepatitis B Antigen): A Conformational Antigen Dependent on Disulfide Bonds

Vyas, Girish N.; Rao, K.R.S. Sambasiva; Ibrahim, Ali Bin

doi:10.1126/science.178.4067.1300

Cited by 106 publications

(45 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Prior to evaluation of mutant HDV particles for infectivity, the particles were examined for antigenicity as an attempt to identify changes induced by the cysteine mutations in the "a" determinant. It was previously shown that reactivity of HBV particles with anti-HBsAg antibodies was dependent upon envelope protein disulfide bonds (39) and that antigenicity of SVPs carrying AGL cysteine mutations was drastically affected (27). Here, we measured the reactivity of each cysteine mutant in two commercial immunoassays (Monolisa HBsAg Ultra from Bio-Rad and ETI-MAK-4 HBsAg from Dia-Sorin).…”

Section: Resultsmentioning

confidence: 99%

Entry of Hepatitis Delta Virus Requires the Conserved Cysteine Residues of the Hepatitis B Virus Envelope Protein Antigenic Loop and Is Blocked by Inhibitors of Thiol-Disulfide Exchange

Abou-Jaoudé

Sureau

2007

J Virol

View full text Add to dashboard Cite

Hepatitis delta virus (HDV) particles are coated with the envelope proteins (large, middle, and small) of the hepatitis B virus (HBV). The large protein bears an infectivity determinant in its pre-S1 domain, whereas a second determinant has been proposed to map to the cysteine-rich antigenic loop (AGL) within the S domain of all three envelope proteins (G. Abou Jaoudé and C. Sureau, J. Virol. 79:10460-10466, 2006). In this study, the AGL cysteines were substituted by serine or alanine, and the mutants were evaluated for their function at viral entry using HDV particles and susceptible HepaRG cells. Mutations of cysteines 121 to 149 were tolerant of the production of HDV virions. The mutations altered the structure and antigenicity of the conserved "a" determinant of the AGL, as measured by conformation-sensitive antibodies, and they created a block to infectivity. Substitution of Cys-90 or Cys-221, located outside of the AGL, had no impact on the "a" determinant or viral entry. Furthermore, infectivity was maintained when the AGL CxxC motif at position 121 to 124 was modified by single-amino-acid deletion or insertion, suggesting that cysteines 121 and 124 are not catalyzers of thiol/disulfide exchange. However, membrane-impermeable inhibitors of thiol/disulfide isomerazation demonstrated a dose-dependent inhibition of infection in an in vitro assay when applied to the virus prior to inoculation or during the virus-cell interaction period. Overall, the results demonstrate the essential role of the AGL cysteines at viral entry, and they establish a correlation between the cysteine disulfide network, the conformation of the "a" determinant, and infectivity.Hepatitis B virus (HBV) is responsible for acute and chronic liver disease that affects more than 400 million individuals worldwide (12). HBV is characterized by a very narrow host range that is likely to reflect a highly specific interaction between the viral envelope proteins and the receptor(s) at the surface of human hepatocytes. The mechanism of HBV entry is still poorly understood-the receptor remains unknownand only recently have determinants of infectivity been mapped to discrete domains within the amino acid sequence of the envelope proteins (2,4,16,24). HBV particles bear three sequence-related envelope proteins: the small protein (SHBsAg) consists of a 226-amino-acid-long transmembrane protein, the middle protein (M-HBsAg) includes the S domain and an additional N-terminal pre-S2 ectodomain that is 55 amino acids in length, and the large protein (L-HBsAg) comprises a N-terminal pre-S1 domain (109 amino acids) in addition to pre-S2 and S domains (20). Synthesis occurs at the endoplasmic reticulum (ER) membrane, but it leads almost exclusively to the secretion of empty subviral particles (SVPs). The assembly of mature HBV virions is a rare event that results from an interaction between the matrix domain of LHBsAg and the HBV nucleocapsid (6).The HBV envelope proteins also have the capacity to interact with the hepatitis delta virus (HDV) ribonucleoprote...

show abstract

Section: Resultsmentioning

confidence: 99%

Entry of Hepatitis Delta Virus Requires the Conserved Cysteine Residues of the Hepatitis B Virus Envelope Protein Antigenic Loop and Is Blocked by Inhibitors of Thiol-Disulfide Exchange

Abou-Jaoudé

Sureau

2007

J Virol

View full text Add to dashboard Cite

show abstract

“…The latter would not be surprising, since conformational effects in HBsAg have long been known. For example, although the molecule contains numerous potential trypsin cleavage sites, only one of these (Lys-122) is susceptible to tryptic attack, even under dissociating conditions (24); similarly, antibodies raised to native HBsAg particles recognize denatured p24s polypeptides poorly or not at all (35).…”

Section: Discussionmentioning

confidence: 99%

Multiple topogenic sequences determine the transmembrane orientation of the hepatitis B surface antigen.

et al. 1987

View full text Add to dashboard Cite

To investigate the mechanisms by which complex membrane proteins achieve their correct transmembrane orientation, we examined in detail the hepatitis B surface antigen for sequences which determine its membrane topology. The results demonstrated the presence of at least two kinds of topogenic elements: an N-terminal uncleaved signal sequence and an internal element containing both signal and stop-transfer functions. Fusion of reporter groups to either end of the protein suggested that both termini are translocated across the membrane bilayer. We propose that this topology is generated by the conjoint action of both elements and involves a specifically oriented membrane insertion event mediated by the internal sequence. The functional properties of each element can be instructively compared with those of simpler membrane proteins and may provide insight into the generation of other complex protein topologies.

show abstract

“…The antigenicity and immunogenicity of this protein (designated S-protein) depends on the maintenance of disulphide bonds (Vyas et al, 1972;Sukeno et al, 1972;Dreesman et al, 1973). The open reading frame on HBV DNA coding for S protein (Charnay et al, 1979;Peterson et al, 1977) has the capacity to code for a protein consisting of 389 to 400 amino acids (depending on the antigenic subtype of HBV).…”

Section: Introductionmentioning

confidence: 99%

Detection of Antiviral Antibodies with Predetermined Specificity Using Synthetic Peptide-beta-Lactamase Conjugates: Application to Antibodies Specific for the preS Region of the Hepatitis B Virus Envelope Proteins

Neurath¹,

Kent²,

Strick³

1986

Journal of General Virology

View full text Add to dashboard Cite

SUMMARYAmino acid sequences coded for by the preS region of the hepatitis B virus (HBV) envelope gene are present both in HBV and in subviral hepatitis B surface antigen (HBsAg) particles. Consequently, anti-preS-specific antibodies are elicited during the course of HBV infection. Such antibodies are virus-neutralizing. Therefore, it is important to determine whether or not vaccination with HBsAg also induces an antipreS-specific immune response. We describe here an enzyme-linked immunosorbent assay applicable for the screening of sera from vaccinated individuals for anti-preS antibodies. IgG from serum specimens was adsorbed to staphylococcal Protein A on a superparamagnetic support and subsequently mixed with a synthetic peptide analogue [preS(120-145)] covalently linked to fl-lactamase. The presence of anti-preS in serum specimens resulted in binding of the conjugated fl-lactamase to the magnetic support. The adsorbed enzyme was quantified colorimetrically.

show abstract

Australia Antigen (Hepatitis B Antigen): A Conformational Antigen Dependent on Disulfide Bonds

Cited by 106 publications

References 14 publications

Entry of Hepatitis Delta Virus Requires the Conserved Cysteine Residues of the Hepatitis B Virus Envelope Protein Antigenic Loop and Is Blocked by Inhibitors of Thiol-Disulfide Exchange

Entry of Hepatitis Delta Virus Requires the Conserved Cysteine Residues of the Hepatitis B Virus Envelope Protein Antigenic Loop and Is Blocked by Inhibitors of Thiol-Disulfide Exchange

Multiple topogenic sequences determine the transmembrane orientation of the hepatitis B surface antigen.

Detection of Antiviral Antibodies with Predetermined Specificity Using Synthetic Peptide-beta-Lactamase Conjugates: Application to Antibodies Specific for the preS Region of the Hepatitis B Virus Envelope Proteins

Contact Info

Product

Resources

About