RESUMEN
The phosphatidylinositol 5-phosphate 4-kinases (PI5P4Ks) are therapeutic targets for diseases such as cancer, neurodegeneration and immunological disorders as they are key components in regulating cell signalling pathways. In an effort to make probe molecules available for further exploring these targets, we have previously reported PI5P4Kα-selective and PI5P4Kγ-selective ligands. Herein we report the rational design of PI5P4Kα/γ dual inhibitors, using knowledge gained during the development of selective inhibitors for these proteins. ARUK2007145 (39) is disclosed as a potent, cell-active probe molecule with ADMET properties amenable to conducting experiments in cells.
RESUMEN
The phosphatidylinositol 5-phosphate 4-kinases (PI5P4Ks) play a central role in regulating cell signalling pathways and, as such, have become therapeutic targets for diseases such as cancer, neurodegeneration and immunological disorders. Many of the PI5P4Kα inhibitors that have been reported to date have suffered from poor selectivity and/or potency and the availability of better tool molecules would facilitate biological exploration. Herein we report a novel PI5P4Kα inhibitor chemotype that was identified through virtual screening. The series was optimised to deliver ARUK2002821 (36), a potent PI5P4Kα inhibitor (pIC50 = 8.0) which is selective vs. other PI5P4K isoforms and has broad selectivity against lipid and protein kinases. ADMET and target engagement data are provided for this tool molecule and others in the series, as well as an X-ray structure of 36 solved in complex with its PI5P4Kα target.
RESUMEN
Owing to their central role in regulating cell signaling pathways, the phosphatidylinositol 5-phosphate 4-kinases (PI5P4Ks) are attractive therapeutic targets in diseases such as cancer, neurodegeneration, and immunological disorders. Until now, tool molecules for these kinases have been either limited in potency or isoform selectivity, which has hampered further investigation of biology and drug development. Herein we describe the virtual screening workflow which identified a series of thienylpyrimidines as PI5P4Kγ-selective inhibitors, as well as the medicinal chemistry optimization of this chemotype, to provide potent and selective tool molecules for further use. In vivo pharmacokinetics data are presented for exemplar tool molecules, along with an X-ray structure for ARUK2001607 (15) in complex with PI5P4Kγ, along with its selectivity data against >150 kinases and a Cerep safety panel.
Asunto(s)
Neoplasias , Transducción de Señal , Humanos , Isoformas de Proteínas , Encéfalo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/químicaRESUMEN
Phosphatidylinositol 5-phosphate 4-kinases (PI5P4Ks) are emerging as attractive therapeutic targets in diseases, such as cancer, immunological disorders, and neurodegeneration, owing to their central role in regulating cell signaling pathways that are either dysfunctional or can be modulated to promote cell survival. Different modes of binding may enhance inhibitor selectivity and reduce off-target effects in cells. Here, we describe efforts to improve the physicochemical properties of the selective PI5P4Kγ inhibitor, NIH-12848 (1). These improvements enabled the demonstration that this chemotype engages PI5P4Kγ in intact cells and that compounds from this series do not inhibit PI5P4Kα or PI5P4Kß. Furthermore, the first X-ray structure of PI5P4Kγ bound to an inhibitor has been determined with this chemotype, confirming an allosteric binding mode. An exemplar from this chemical series adopted two distinct modes of inhibition, including through binding to a putative lipid interaction site which is 18 Å from the ATP pocket.
Asunto(s)
Adenosina Trifosfato/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Quinazolinas/síntesis química , Quinazolinas/farmacología , Tiofenos/síntesis química , Tiofenos/farmacología , Regulación Alostérica/efectos de los fármacos , Unión Competitiva , Cristalografía por Rayos X , Humanos , Modelos Moleculares , Simulación del Acoplamiento Molecular , Fosfotransferasas (Aceptor de Grupo Alcohol)/química , Especificidad por SustratoRESUMEN
KEAP1 is the key regulator of the NRF2-mediated cytoprotective response, and increasingly recognized as a target for diseases involving oxidative stress. Pharmacological intervention has focused on molecules that decrease NRF2-ubiquitination through covalent modification of KEAP1 cysteine residues, but such electrophilic compounds lack selectivity and may be associated with off-target toxicity. We report here the first use of a fragment-based approach to directly target the KEAP1 Kelch-NRF2 interaction. X-ray crystallographic screening identified three distinct "hot-spots" for fragment binding within the NRF2 binding pocket of KEAP1, allowing progression of a weak fragment hit to molecules with nanomolar affinity for KEAP1 while maintaining drug-like properties. This work resulted in a promising lead compound which exhibits tight and selective binding to KEAP1, and activates the NRF2 antioxidant response in cellular and in vivo models, thereby providing a high quality chemical probe to explore the therapeutic potential of disrupting the KEAP1-NRF2 interaction.
Asunto(s)
Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Animales , Células Cultivadas , Cristalografía por Rayos X , Descubrimiento de Drogas , Humanos , Proteína 1 Asociada A ECH Tipo Kelch/química , Ratones , Factor 2 Relacionado con NF-E2/química , Unión ProteicaRESUMEN
Reflex is a recent algorithm in the de novo ligand design software, SkelGen, that allows the flexibility of amino acid side chains in a protein to be taken into account during the drug-design process. In this paper the impact of flexibility on the solutions generated by the de novo design algorithm, when applied to carboxypeptidase A, acetylcholinesterase, and the estrogen receptor (ER), is investigated. The results for each of the targets indicate that when allowing side-chain movement in the active site, solutions are generated that were not accessible from the multiple static protein conformations available for these targets. Furthermore, an analysis of structures generated in a flexible versus a static ER active site suggests that these additional solutions are not merely noise but contain many interesting chemotypes.
Asunto(s)
Acetilcolinesterasa/química , Algoritmos , Carboxipeptidasas A/química , Diseño de Fármacos , Receptores de Estrógenos/química , Acetilcolinesterasa/metabolismo , Sitios de Unión , Carboxipeptidasas A/metabolismo , Ligandos , Movimiento (Física) , Docilidad , Conformación Proteica , Receptores de Estrógenos/metabolismo , Relación Estructura-ActividadRESUMEN
From a set of weakly potent lead compounds, using in silico screening and small library synthesis, a series of 2-alkyl-3-aryl-3-alkoxyisoindolinones has been identified as inhibitors of the MDM2-p53 interaction. Two of the most potent compounds, 2-benzyl-3-(4-chlorophenyl)-3-(3-hydroxypropoxy)-2,3-dihydroisoindol-1-one (76; IC(50) = 15.9 +/- 0.8 microM) and 3-(4-chlorophenyl)-3-(4-hydroxy-3,5-dimethoxybenzyloxy)-2-propyl-2,3-dihydroisoindol-1-one (79; IC(50) = 5.3 +/- 0.9 microM), induced p53-dependent gene transcription, in a dose-dependent manner, in the MDM2 amplified, SJSA human sarcoma cell line.
Asunto(s)
Antineoplásicos/síntesis química , Indoles/síntesis química , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Técnicas Químicas Combinatorias , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Indoles/química , Indoles/farmacología , Modelos Moleculares , Unión Proteica , Estereoisomerismo , Relación Estructura-Actividad , Transcripción Genética , Proteína p53 Supresora de Tumor/genéticaRESUMEN
A de novo design approach to generating novel estrogen receptor (ER) ligands is described. The SkelGen program was used to generate ligands in the active sites of seven crystal structures of ERalpha. Seventeen high-scoring, diverse structures were selected from the SkelGen output and synthesized without introducing any modifications to the structures. Five ligands, four of which are novel, showed < or = 25 microM affinity, with the best compound displaying an IC50 of 340 nM. SkelGen can, therefore, be a powerful tool for designing active molecules.
Asunto(s)
Diseño de Fármacos , Receptores de Estrógenos/química , Programas Informáticos , Relación Estructura-Actividad , Unión Competitiva , Humanos , Concentración 50 Inhibidora , Ligandos , Modelos Biológicos , Estructura Molecular , Receptores de Estrógenos/agonistas , Receptores de Estrógenos/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genéticaRESUMEN
A series of 2-N-alkyl-3-aryl-3-alkoxyisoindolinones has been synthesised and evaluated as inhibitors of the MDM2-p53 interaction. The most potent compound, 3-(4-chlorophenyl)-3-(4-hydroxy-3,5-dimethoxybenzyloxy)-2-propyl-2,3-dihydroisoindol-1-one (NU8231), exhibited an IC50 of 5.3 +/- 0.9 microM in an ELISA assay, and induced p53-dependent gene transcription in a dose-dependent manner, in the SJSA human sarcoma cell line.