Source : Escherichia Coli. Recombinant hepatitis B virus 'e' antigen produced in E.coli, is a 139 a.a. protein. The HBeAg sequence is derived from HBV adw2 and fused to 6xHis Tag at C-terminus. Hepatitis B virus is the main cause for human liver disease, chronic infection frequently causes liver cancer and cirrhosis. The HBV core gene codes 2 distinct protein products, a 21.5-kDa protein being assembled to form nucleocapsid particles designated HBcAg, which wraps the viral DNA as well as the viral polymerase and RNase H, and a precore protein, designated as HBeAg, which is directly to the endoplasmic reticulum, processed at N- and C-terminally and secreted as non-particulate e-anitgen (HBeAg). The pre-core protein contains an extra 29 N-terminal amino acids, serving as a signal peptide to direct the nascent polypeptide into secretory pathway. After the secretion, mature HBeAg is deleted at the residue 149 C-terminally and retains 10 precore residues N-terminally. HBcAg and HBeAg are distinctly recognized by antibodies but highly cross-reactive at the T-cell level.The e antigen is found in the circulation, it is found during the active HBV infection, positive result indicates the risk for contagiousness, and is also used as indicator for the effectiveness of HBV treatment. Positive anti-HBeAg specifies an active stage of acute HBV infection that is in its final stages, the risk for contagiousness is dramatically reduced.
