Assuntos
Antipsicóticos/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Clozapina/efeitos adversos , Esquizofrenia Paranoide/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Esquizofrenia Paranoide/diagnósticoRESUMO
Peptides based on the amino (N) and carboxy (C)-terminal regions of human immunodeficiency virus type-1 (HIV-1) protease and on the C-terminus of p6* can inhibit HIV-1 protease activity by preventing dimerization. We developed a peptide dimerization inhibitor, P27, that included these domains and a cell permeable domain derived from HIV-1 Tat. P27 inhibited wild type (WT) and protease inhibitor (PI)-resistant HIV-1 protease (IC50: 0.23-0.32 microM). Kinetic and biochemical assays confirmed that P27 inhibits protease dimerization. Fluorescein-labeled peptide accumulated in MT-2 cells and protected acutely infected MT-2 cells from HIV-1-induced cytotoxicity (IC50: 5.1 microM). P27 also inhibited p24 accumulation from H9 and U937 cells chronically infected with WT or PI-resistant HIV-1. Immunoblot analysis on the supernatants and infected cells revealed a block in virus release by P27 rather than an inhibition of polyprotein processing. However, inhibition of p55 Gag processing by active-site inhibitors was enhanced when combined with P27, suggesting that P27 can affect protease function in maturing virions. Although P27 was rationally designed to block dimerization of the mature HIV-1 protease, the effects of P27 on HIV-1 replication may be related to partial inhibition of Gag-Pol processing leading to a disruption in virus release.
Assuntos
Inibidores da Protease de HIV/farmacologia , Protease de HIV/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Peptídeos/farmacologia , Replicação Viral/efeitos dos fármacos , Linhagem Celular , Dimerização , Proteínas de Fusão gag-pol/metabolismo , Produtos do Gene tat/genética , Proteína do Núcleo p24 do HIV/metabolismo , Protease de HIV/genética , Protease de HIV/metabolismo , HIV-1/fisiologia , Humanos , Processamento de Proteína Pós-Traducional , Linfócitos T/química , Linfócitos T/virologia , Produtos do Gene tat do Vírus da Imunodeficiência HumanaRESUMO
Human immunodeficiency virus protease activity can be regulated by reversible oxidation of a sulfur-containing amino acid at the dimer interface. We show here that oxidation of this amino acid in human immunodeficiency virus type 1 protease prevents dimer formation. Moreover, we show that human T-cell leukemia virus type 1 protease can be similarly regulated through reversible glutathionylation of its two conserved cysteine residues. Based on the known three-dimensional structures and multiple sequence alignments of retroviral proteases, it is predicted that the majority of retroviral proteases have sulfur-containing amino acids at the dimer interface. The regulation of protease activity by the modification of a sulfur-containing amino acid at the dimer interface may be a conserved mechanism among the majority of retroviruses.