The first open reading frame of the HIV genome has been identified as the gag gene. The proteins encoded by this gene are p17 as the amino-terminal protein, p24 as the middle peptide, and p15 as the carboxyl-terminal end. A monoclonal antibody recognizing an antigenic determinant on a fragment of p15 has been developed and designated M35/2F8. This monoclonal has been instrumental in radiosequencing the carboxyl-terminal product of p15, p6, and in determining the cleavage site between this protein and the amino-terminal product, p7. By immunoaffinity chromatography it was also possible to purify p6 from HIV lysates and all p6 containing polyproteins from HIV-infected cells. These results gave more insight into the composition and processing of the HIV gag gene.
