Recombinant Hepatitis B virus Hepatitis B Surface Antigen AD protein

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

The Hepatitis B Surface Antigen AD also known as HBsAg protein or HBV protein is an important component of the hepatitis B virus (HBV). This protein forms a structural element of the viral envelope with an approximate mass of 24 kilodaltons. It is expressed on the surface of infected hepatocytes which are liver cells. HBsAg contributes to the virus's ability to attach to and enter cells playing an essential role in the viral infective cycle. The Hep B recombinant protein produced in labs assists in studying this mechanism.

Biological function summary

The HBsAg protein plays a critical role in immune evasion. It forms part of non-infectious virus-like particles in the bloodstream which can reach high concentrations. These particles help the virus avoid the host's immune response complicating the clearance of infection. HBsAg is not part of a complex but acts independently to bind to receptors on host cells facilitating viral entry and subsequent replication of HBV proteins. Its function in immune modulation highlights its importance beyond mere structural roles.

Pathways

The HBsAg protein is heavily involved in the viral replication and infection pathways of HBV. It interacts with the hepatocyte sodium taurocholate cotransporting polypeptide (NTCP) a receptor critical for HBV entry into liver cells. This protein assists in establishing persistent infection. Moreover HBsAg influences the host's immune signaling pathways including the inhibition of pathways that lead to interferon production critical for antiviral responses. The protein balances viral replication with evasion of the immune system.

The Hepatitis B Surface Antigen AD links directly to hepatitis B infection and its chronic liver consequences. Hepatitis B can progress to serious conditions like liver cirrhosis and hepatocellular carcinoma if untreated. HBsAg remains a major marker for active infection and a vaccine target to prevent disease progression. The presence of this protein indicates viral replication and its persistence in the bloodstream is associated with chronic hepatitis B infection. Additionally HBsAg's relationship with proteins like HBx which is involved in the development of liver cancer illustrates its role in disease pathogenesis.