RESUMO
Synthetic genes encoding the gag p24 and the part of the envelope protein gp41 of the human immunodeficiency virus (HIV-1) were cloned and overexpressed as fusion proteins in Escherichia coli, using an expression vector carrying 77 promoter and the poly-histidine leader sequence. The overexpressed p24 fusion protein was purified by centrifugation, Ni-affinity chromatography and CM-sepharose chromatography The overexpressed gp41 fusion protein was purified by centrifugation, C4 chromatography and DEAE-sepharose chromatography. The purified fusion proteins showed a high level of purity and immunoreactivity in SDS-polyacrylamide gel electrophoresis and western blot analysis. These results suggest that this prokaryotic expression-purification method is suitable for obtaining a large amount of the viral antigen which may be useful for screening of antibodies to HIV-1 in human blood samples.