HETEROLOGOUS EPITOPES IN THE CENTRAL REGION OF HEPATITIS-B VIRUS COREPROTEIN

Several fragments of the preS region of the hepatitis B virus core pro tein were introduced into the central region of the nucleocapsid prote in (HBcAg) of this virus. It was shown that polypeptides containing fr agments 31-36 and 94-105 form aggregates similar to the 27-nm particle of HBcAg and display the antigenic activity typical of both HBcAg and the epitopes introduced. Meanwhile, introduction of fragment 133-143 (preS2 region) or a trimer of fragment 94-105 (preS1) into the central region of HBcAg changes the hydrophobicity of the latter. A hybrid pr otein was designed containing a fragment of preS2 at the N terminus an d a fragment of preS1 in the central region. It was shown that the epi tope in the central region of HBcAg is presented more efficiently than at its N terminus if the particles retain the ability to aggregate.