RESUMEN
The tyrosine kinase p56lck (lck) is essential for T cell activation; thus, inhibitors of lck have potential utility as autoimmune agents. Our initial disclosure of a new class of lck inhibitors based on the phenylaminoimidazoisoquinolin-9-one showed reasonable cellular activity but did not work in vivo upon oral administration. Our current work highlights the further use of rational drug design and molecular modeling to produce a series of lck inhibitors that demonstrate cellular activity below 100 nM and are as efficacious as cyclosporin A in an in vivo mouse model of anti-CD3-induced IL-2 production.
Asunto(s)
Bencimidazoles/síntesis química , Inhibidores Enzimáticos/síntesis química , Inmunosupresores/síntesis química , Isoquinolinas/síntesis química , Proteína Tirosina Quinasa p56(lck) Específica de Linfocito/antagonistas & inhibidores , Administración Oral , Animales , Anticuerpos Monoclonales/farmacología , Bencimidazoles/química , Bencimidazoles/farmacología , Complejo CD3/inmunología , Cristalografía por Rayos X , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Femenino , Humanos , Inmunosupresores/química , Inmunosupresores/farmacología , Interleucina-2/antagonistas & inhibidores , Interleucina-2/biosíntesis , Interleucina-2/sangre , Isoquinolinas/química , Isoquinolinas/farmacología , Células Jurkat , Ratones , Ratones Endogámicos BALB C , Modelos Moleculares , Conformación Molecular , Unión Proteica , Relación Estructura-ActividadRESUMEN
The specificity of the immune response relies on processing of foreign proteins and presentation of antigenic peptides at the cell surface. Inhibition of antigen presentation, and the subsequent activation of T-cells, should, in theory, modulate the immune response. The cysteine protease Cathepsin S performs a fundamental step in antigen presentation and therefore represents an attractive target for inhibition. Herein, we report a series of potent and reversible Cathepsin S inhibitors based on dipeptide nitriles. These inhibitors show nanomolar inhibition of the target enzyme as well as cellular potency in a human B cell line. The first X-ray crystal structure of a reversible inhibitor cocrystallized with Cathepsin S is also reported.
Asunto(s)
Catepsinas/síntesis química , Dipéptidos/síntesis química , Inhibidores Enzimáticos/síntesis química , Nitrilos/síntesis química , Linfocitos B/efectos de los fármacos , Unión Competitiva , Catepsinas/química , Catepsinas/farmacología , Línea Celular , Cristalografía por Rayos X , Dipéptidos/química , Dipéptidos/farmacología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Cinética , Modelos Moleculares , Nitrilos/química , Nitrilos/farmacología , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
The p38 MAP kinase plays a crucial role in regulating the production of proinflammatory cytokines, such as tumor necrosis factor and interleukin-1. Blocking this kinase may offer an effective therapy for treating many inflammatory diseases. Here we report a new allosteric binding site for a diaryl urea class of highly potent and selective inhibitors against human p38 MAP kinase. The formation of this binding site requires a large conformational change not observed previously for any of the protein Ser/Thr kinases. This change is in the highly conserved Asp-Phe-Gly motif within the active site of the kinase. Solution studies demonstrate that this class of compounds has slow binding kinetics, consistent with the requirement for conformational change. Improving interactions in this allosteric pocket, as well as establishing binding interactions in the ATP pocket, enhanced the affinity of the inhibitors by 12,000-fold. One of the most potent compounds in this series, BIRB 796, has picomolar affinity for the kinase and low nanomolar inhibitory activity in cell culture.