Successful mimicry of a complex viral antigen by multiple peptide insertions in a carrier protein

The antigenic properties of a viral peptide from the surface of foot-and-mo uth disease virus particles have been successfully mimicked by multiple ins ertion in solvent-exposed regions of Escherichia coli beta-galactosidase. B y increasing the number of viral peptides per enzyme monomer, the average I C50 of hybrid proteins in a competitive enzyme-linked immunosorbent assay) have decreased to values close to that presented by natural virions, Moreov er, the antigenic diversity of these nerv recombinant enzymes when measured with different anti-virus antibodies has also been largely reduced, indica ting a better presentation of the epitopes located in the viral peptide. Al though bivalent antibody binding could have been favoured by multiple prese ntation, conformational modifications of the viral peptide, due to the pres ence of other insertions or a cooperative antibody binding cannot be exclud ed. In addition, a multidimensional antigenic analysis have grouped togethe r the multiple-inserted proteins with the native virus, suggesting that inc reasing the number of insertions could be a good strategy to reproduce the antigenic properties of an immunoreactive peptide in a natural multimeric d isposition. (C) 2000 Federation of European Biochemical Societies.