RESUMO
5-(Hetero)aryl-3-(4-carboxamidophenyl)-2-aminopyridine inhibitors of CHK2 were identified from high throughput screening of a kinase-focussed compound library. Rapid exploration of the hits through straightforward chemistry established structure-activity relationships and a proposed ATP-competitive binding mode which was verified by X-ray crystallography of several analogues bound to CHK2. Variation of the 5-(hetero)aryl substituent identified bicyclic dioxolane and dioxane groups which improved the affinity and the selectivity of the compounds for CHK2 versus CHK1. The 3-(4-carboxamidophenyl) substituent could be successfully replaced by acyclic omega-aminoalkylamides, which made additional polar interactions within the binding site and led to more potent inhibitors of CHK2. Compounds from this series showed activity in cell-based mechanistic assays for inhibition of CHK2.
Assuntos
Aminopiridinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Aminopiridinas/síntese química , Aminopiridinas/química , Sítios de Ligação , Linhagem Celular , Quinase do Ponto de Checagem 2 , Cristalografia por Raios X , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
There is presently enormous interest in the function and regulatory roles of histone acetyltransferase enzymes. Along with deacetylases it is now evident that these enzymes play a key role in many cellular processes including chromatin remodeling and gene transcription. As such, effective small molecule enzyme inhibitors would be useful tools for molecular pharmacology and may also be suitable for further development into agents for the treatment of diseases such as cancer. A high-throughput assay based on the use of scintillating microplates (FlashPlates) suitable for screening libraries of compounds for inhibitors of acetylase activity is described here. Confirmation of activity of selected compounds is achieved with a conventional filter assay, the details of which are also described. In addition, an assay suitable for confirming that cellular protein acetylation has been altered by inhibition of acetylases or deacetylases is also presented. On the same plate, cells are grown, exposed to compound, fixed, and permeabilized, and protein acetylation is determined using standard ELISA methodology and a europium-labeled second antibody. This latter method provides a medium-throughput alternative to the use of immunoblotting for mechanistic studies.