HBV core (1-183)
Description
Role in the HBV Life Cycle
The HBV core protein is pivotal at multiple stages:
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Capsid Assembly: Dimers self-assemble into capsids via hydrophobic interactions, forming a scaffold for pgRNA packaging .
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pgRNA Encapsidation: Requires interaction with HBV polymerase and HBx protein .
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Reverse Transcription: Capsids protect viral RNA during DNA synthesis .
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cccDNA Formation: Transports viral DNA to the nucleus for cccDNA integration .
Critical Mutations:
3.2. Phosphorylation and Replication
HBx protein stimulates phosphorylation of NABD serines (155, 162, 170), enabling:
| Phosphorylation Site | Function | Regulator |
|---|---|---|
| Ser155 | pgRNA packaging | HBx |
| Ser162 | Reverse transcription initiation | HBx |
| Ser170 | DNA replication fidelity | HBx |
3.3. Host Protein Interactions
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Par14/Par17: Bind the conserved 133RP134 motif in AD, stabilizing capsids and enhancing replication . Mutation of R133 to D/E abolishes binding and capsid assembly .
4.1. Capsid Inhibitors
| Compound Class | Mechanism | Key Examples |
|---|---|---|
| HAPs | Induce capsid misassembly | BAY 41–4109, GLS4 |
| Dimer-Dimer Disruptors | Target AD dimer interfaces | pHBc120-135M |
Key Findings:
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pHBc120-135M: Reduces WT virion production by >50% via AD disruption .
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Y132 Mutation: Blocks Par14/Par17 binding, impairing replication .
4.2. Diagnostic and Detection Tools
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Human mAbs:
Clinical Relevance and Pathogenesis
Product Specs
Product Science Overview
Hepatitis B virus (HBV) is a significant global health concern, causing both acute and chronic liver infections. The virus is a member of the Hepadnaviridae family and is known for its unique replication strategy, which involves reverse transcription of its pregenomic RNA (pgRNA) into DNA. One of the critical components of HBV is the core protein, also known as HBcAg (Hepatitis B core antigen), which plays a vital role in the virus’s life cycle.
The HBV core protein is a structural protein that forms the nucleocapsid, encapsulating the viral DNA and polymerase. The full-length core protein consists of 183 amino acids (a.a.), with the first 149 amino acids forming the assembly domain responsible for capsid formation, and the remaining C-terminal region (a.a. 150-183) being rich in arginine residues, which are crucial for nucleic acid binding .
The recombinant HBV core protein (1-183 a.a.) is typically expressed in Escherichia coli (E. coli) and purified using chromatographic techniques. This recombinant protein retains the immunodominant regions of the native core protein, making it useful for various research and diagnostic applications .
The HBV core protein is essential for the virus’s replication and assembly. After the virus enters a hepatocyte, the core protein assembles into a capsid around the pgRNA and viral polymerase. This capsid then undergoes reverse transcription to produce relaxed circular (RC) DNA, which can either be enveloped and secreted as a virion or transported back to the nucleus to form covalently closed circular DNA (cccDNA), serving as a template for further viral replication .
Phosphorylation of the HBV core protein, particularly in the C-terminal domain, plays a crucial role in regulating its interactions with nucleic acids. Specific phosphorylation sites have been identified, and their occupancy can significantly impact RNA binding and capsid structure. For instance, phosphorylation by serine-arginine protein kinase 1 (SRPK1) has been shown to reduce non-specific RNA encapsidation, thereby facilitating the selective packaging of the pgRNA/polymerase complex .
The recombinant HBV core protein (1-183 a.a.) is widely used in research to study the virus’s structure, replication, and interactions with host cells. It is also employed in diagnostic assays to detect antibodies against HBV in infected individuals. The high purity and immunoreactivity of the recombinant protein make it a valuable tool for these purposes .
