Four distinct antigenic regions are present in the primary structure of HIV-1 and HIV-2 proteinases.

ABSTRACT

OBJECTIVE: The purpose of this study was to assay reactivity of antibody-positive sera to different parts of the HIV-1 and HIV-2 proteinase (PR) proteins. DESIGN: Since the majority of HIV-1-antibody-positive sera react to the proteinase, but the antigenic determinants on the protein have not been identified, we attempted to identify these determinants. INTERVENTIONS: We synthesized 18 peptides representing the PR of HIV-1 and HIV-2 in order to map serum reactivity to the PR protein. RESULTS: Both HIV-1- and HIV-2-antibody-positive sera recognized four distinct antigenic regions in the HIV-1 and HIV-2 PR. CONCLUSIONS: Correlation between our results and the crystallographic structure of the protein revealed that the antigenic regions are positioned at the surface of the HIV-1 PR. Although the structure of HIV-2 PR has not yet been characterized, our results indicate that the folding of the HIV-1 and HIV-2 PR may be very similar.