Hepatitis B virus capsid core protein (HBcAg)

The Hepatitis B virus capsid core protein (HBcAg) is a 183-amino acid structural protein that self-assembles into the icosahedral nucleocapsid of the virus (UniProt P03147). It plays a multifaceted role in the HBV life cycle, including the selective packaging of the pregenomic RNA (pgRNA)-polymerase complex and providing the specialized environment required for reverse transcription (PubMed: 31536730). Additionally, the core protein is involved in the nuclear import of the viral genome and the regulation of covalently closed circular DNA (cccDNA) formation (PubMed: 32653444). As a therapeutic target, HBcAg is addressed by Capsid Assembly Modulators (CAMs), which interfere with the precise assembly process to produce either empty or misassembled capsids, effectively blocking viral replication. These modulators are categorized into Class I (inducing aberrant polymers) and Class II (inducing empty capsids) based on their structural impact on the core protein assembly (PubMed: 30249040). Targeting this protein is a key strategy in current efforts to achieve a functional cure for chronic hepatitis B infection.

Other names

HBV core proteinHBcp21.5Capsid proteinCore antigenHBV Cp

Capsid assembly modulation (CAM) through either the induction of aberrant, non-capsid polymers (Class I) or the formation of empty, genome-deficient capsids (Class II), thereby inhibiting viral replication and pregenomic RNA packaging.