Hepatitis B virus large envelope protein (LHBs or L protein)

The hepatitis B virus large envelope protein (LHBs) is one of three related surface glycoproteins (large, middle, small) forming the viral envelope. It comprises preS1, preS2, and S domains, with the preS1 region mediating binding to the hepatocyte entry receptor NTCP and playing a pivotal role in viral entry. LHBs has two membrane topologies (external and internal) allowing it to mediate both initial cell entry and subsequent assembly of virus particles by bridging to the nucleocapsid. Its accumulation in the endoplasmic reticulum is associated with cellular stress and is implicated in tumorigenesis. LHBs is highly antigenic, with its “a” determinant serving as a major target for host antibodies. Therapeutics target its receptor-binding domain, antigenic domains, or assembly interactions to block infection, and diagnostic assays frequently rely on detection of the protein or its antibodies.

Other names

Hepatitis B virus L proteinHBV large surface antigenLHBsAgLarge hepatitis B surface antigen

Blocking receptor-binding (preS1 domain antibody or peptide inhibitors interfere with NTCP interaction); Inhibition of viral assembly (drugs interrupt core-envelope protein interactions); Disruption of envelope formation and secretion through direct L protein binding