A hepatitis B surface antigen mutant that lacks the antigenic loop region can self-assemble and interact with the large hepatitis delta antigen

A novel hepatitis B virus surface antigen mutant harboring a deletion of most of the major antigenic loop region was competent for self-assembly and secretion. Although the mutant protein was competent for interaction with and incorporation of free large hepatitis delta antigen, it was partially defective in hepatitis delta virus RNP incorporation.