Comparing tandem repeats and multiple antigenic peptides as the antigens to detect antibodies by enzyme immunoassay

Short synthetic peptides are useful alternatives to whole lysate or recombi nant proteins as the antigens used for serodiagnosis of bacterial or viral infections. However, certain known antigenic peptides displayed low serorea ctivities in direct enzyme immunoassay. This was believed to be due to the low coating efficiency, a constrained orientation, or loss of flexibility r equired for optimal antibody binding. Using a model peptide system derived from the V3-loop of HIV-1 gp120, we demonstrated that low antigenicity coul d be overcome by using either tandem repeats (TR) or multiple antigenic pep tides (MA-Ps) which contained the same amino acid sequence as the monomeric peptide. In our model system, a four-branch MAP was a better choice compar ed to the tandem repeats because of the MAP's slightly higher sensitivity a nd lower cost of production. (C) 2001 Elsevier Science B.V. All rights rese rved.