Assuntos
Antivirais/farmacologia , Hepacivirus/metabolismo , Mutação , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Domínio Catalítico , Química Farmacêutica/métodos , Desenho de Fármacos , Deleção de Genes , Glicina/química , Concentração Inibidora 50 , Conformação Molecular , Peptídeos/química , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , TermodinâmicaRESUMO
Azapeptides are known inhibitors of several serine and cysteine proteases. In seeking different classes of inhibitors for the HCV serine protease, a series of novel azapeptide-based inhibitors were investigated which incorporated noncleavable P1/P1' aza-amino acyl residues. Extensive SAR studies around the P1/P1' aza-amino acyl fragment resulted in the identification of potent and selective inhibitors. Using NMR studies, we have shown that this series of inhibitors bind in a noncovalent competitive fashion to the NS3 protease active site. The bound conformation of one of these new azapeptide-based inhibitors was determined using the transfer NOE technique. Incorporation of these new aza-amino acyl functionalities in the P1 position provided a handle to probe for new interactions in the S' region of the enzyme.
Assuntos
Compostos Aza/síntese química , Hepacivirus/química , Peptídeos/síntese química , Serina Endopeptidases/química , Inibidores de Serina Proteinase/síntese química , Proteínas não Estruturais Virais/antagonistas & inibidores , Compostos Aza/química , Sítios de Ligação , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Peptídeos/química , Inibidores de Serina Proteinase/química , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/químicaRESUMO
Hepatitis C virus (HCV) infection is a serious cause of chronic liver disease worldwide with more than 170 million infected individuals at risk of developing significant morbidity and mortality. Current interferon-based therapies are suboptimal especially in patients infected with HCV genotype 1, and they are poorly tolerated, highlighting the unmet medical need for new therapeutics. The HCV-encoded NS3 protease is essential for viral replication and has long been considered an attractive target for therapeutic intervention in HCV-infected patients. Here we identify a class of specific and potent NS3 protease inhibitors and report the evaluation of BILN 2061, a small molecule inhibitor biologically available through oral ingestion and the first of its class in human trials. Administration of BILN 2061 to patients infected with HCV genotype 1 for 2 days resulted in an impressive reduction of HCV RNA plasma levels, and established proof-of-concept in humans for an HCV NS3 protease inhibitor. Our results further illustrate the potential of the viral-enzyme-targeted drug discovery approach for the development of new HCV therapeutics.
Assuntos
Antivirais/uso terapêutico , Carbamatos/farmacologia , Hepacivirus/efeitos dos fármacos , Hepacivirus/fisiologia , Hepatite C/tratamento farmacológico , Compostos Macrocíclicos , Quinolinas , Inibidores de Serina Proteinase/uso terapêutico , Tiazóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Antivirais/administração & dosagem , Antivirais/farmacocinética , Antivirais/farmacologia , Carbamatos/administração & dosagem , Carbamatos/química , Carbamatos/farmacocinética , Método Duplo-Cego , Hepacivirus/enzimologia , Hepacivirus/genética , Hepatite C/virologia , Humanos , Masculino , Poliproteínas/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Inibidores de Serina Proteinase/administração & dosagem , Inibidores de Serina Proteinase/farmacocinética , Inibidores de Serina Proteinase/farmacologia , Tiazóis/administração & dosagem , Tiazóis/química , Tiazóis/farmacocinética , Carga Viral , Proteínas não Estruturais Virais/metabolismo , Proteínas Virais/metabolismoRESUMO
The hepatitis C virus (HCV) NS3 protease is essential for polyprotein maturation and viral propagation, and it has been proposed as a suitable target for antiviral drug discovery. An N-terminal hexapeptide cleavage product of a dodecapeptide substrate identified as a weak competitive inhibitor of the NS3 protease activity was optimized to a potent and highly specific inhibitor of the enzyme. The effect of this potent NS3 protease inhibitor was evaluated on replication of subgenomic HCV RNA and compared with interferon-alpha (IFN-alpha), which is currently used in the treatment of HCV-infected patients. Treatment of replicon-containing cells with the NS3 protease inhibitor or IFN-alpha showed a dose-dependent decrease in subgenomic HCV RNA that reached undetectable levels following a 14-day treatment. Kinetic studies in the presence of either NS3 protease inhibitor or IFN-alpha also revealed similar profiles in HCV RNA decay with half-lives of 11 and 14 h, respectively. The finding that an antiviral specifically targeting the NS3 protease activity inhibits HCV RNA replication further validates the NS3 enzyme as a prime target for drug discovery and supports the development of NS3 protease inhibitors as a novel therapeutic approach for HCV infection.