Macromolecular self-association of a synthetic peptide derived from the hepatitis B surface antigen: construction of a quaternary epitope.

A major impediment to the development of peptide vaccines has been the inability accurately to mimic conformationally constrained epitopes on the envelope proteins of pathogens. This limitation is further compounded by the fact that several viral envelope proteins exist either as covalently or non-covalently associated homo-oligomers in the native state. Evidence is now accumulating to indicate that, at least in some instances, these homo-oligomers display antigenic determinants that are not present in the dissociated monomer units. Clearly this problem will have to be addressed if peptide-based vaccines are ever to become feasible alternatives. In this report we demonstrate that an oligomerized synthetic peptide that was derived from the hepatitis B surface antigen aggregates in solution to form macromolecular structures. These aggregates appear to represent a 'native' form of the group-specific determinant presented by the hepatitis B surface antigen.