Location of epitopes on the major core protein p24 of human immunodeficiency virus.

Antibody-binding sites were mapped on all overlapping nonapeptides of the major core protein p24 of human immunodeficiency virus type 1 (HIV-1) using murine monoclonal antibodies (MAbs) and sheep and rabbit polyclonal antibodies raised against HIV-1/H9 (strain IIIB) viral lysate and antibodies obtained from humans infected with HIV-1. The binding sites were mapped to various distinct regions of this protein. After superimposition of the antibody-binding sites on a proposed model of p24 of HIV-1, these sites appeared to be located on the surface of the protein on loops, turns and coils of p24 but, unexpectedly, not on the major part of the predicted 'puff'. Little reaction was found with the inaccessible anti-parallel beta-barrel. These results are the first experimental evidence for the validity of the structure proposed for p24 of HIV-1.