Hep B eAg Background Information The “core” ORF of the Hep B (Hepatitis B) genome encodes two related yet functionally distinct proteins: the Hep B core protein, a major component of the nucleocapsid, and the Hep B eAg, a secreted protein. The Hep B eAg gene, so named due to its early appearance during acute Hep B infection, encodes a hydrophobic transmembrane domain, resulting in translation/translocation of Hep B eAg to the lumen of the ER. There, a signal peptidase removes 19 of the 29 residues of Hep B eAg, preventing it from forming into core particles. The presence of Hep B eAg in serum indicates active viral replication in hepatocytes, and associates with an increased risk of hepatocellular carcinoma.
