RESUMO
HIV-1 and HIV-2 proteases (PR) which play the key role in the formation of infectious viral particles offer a target for inhibitors that could block the maturation step. Inhibitors o HIV-1 PR exhibit mostly 1-2 orders of magnitude weaker affinity for HIV-2 PR. The subsite specificity study of the HIV-1 and HIV-2 proteases performed with inhibitors varying in the type of nonhydrolysable bonds and amino acid residues in the P1, P1'and P2'positions has led us to the design of inhibitors with 2S,4S and 2R,4S stereomeres of the hydroxyethylene isostere and Glu or Gln in the P2'positions. These compounds inhibit HIV-1 and HIV-2 proteases in vitro in subnanomolar concentrations and exhibit the activity in tissue culture.
Assuntos
Fármacos Anti-HIV/farmacologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores da Protease de HIV/farmacologia , Protease de HIV/metabolismo , Oligopeptídeos/farmacologia , Animais , Fármacos Anti-HIV/química , Fármacos Anti-HIV/uso terapêutico , Células COS , Desenho de Fármacos , Etilenos , Produtos do Gene gag/biossíntese , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/química , HIV-1/genética , HIV-1/fisiologia , Humanos , Oligopeptídeos/química , Proteínas Recombinantes/biossíntese , Saquinavir/química , Saquinavir/farmacologia , Saquinavir/uso terapêutico , Estereoisomerismo , Relação Estrutura-Atividade , TransfecçãoRESUMO
Differences in virion RNA dimer stability between mature and protease-defective (immature) forms of human immunodeficiency virus type 1 (HIV-1) suggest that maturation of the viral RNA dimer is regulated by the proteolytic processing of the HIV-1 Gag and Gag-Pol precursor proteins. However, the proteolytic processing of these proteins occurs in several steps denoted primary, secondary, and tertiary cleavage events and, to date, the processing step associated with formation of stable HIV-1 RNA dimers has not been identified. We show here that a mutation in the primary cleavage site (p2/nucleocapsid [NC]) hinders formation of stable virion RNA dimers, while dimer stability is unaffected by mutations in the secondary (matrix/capsid [CA], p1/p6) or a tertiary cleavage site (CA/p2). By introducing mutations in a shared cleavage site of either Gag or Gag-Pol, we also show that the cleavage of the p2/NC site in Gag is more important for dimer formation and stability than p2/NC cleavage in Gag-Pol. Electron microscopy analysis of viral particles shows that mutations in the primary cleavage site in Gag but not in Gag-Pol inhibit viral particle maturation. We conclude that virion RNA dimer maturation is dependent on proteolytic processing of the primary cleavage site and is associated with virion core formation.