RESUMEN
The development of 1,3,4,4a,5,10a-hexahydropyrano[3,4-b]chromene analogs as BACE1 inhibitors is described. Introduction of the spirocyclic pyranochromene scaffold yielded several advantages over previous generation cores, including increased potency, reduced efflux, and reduced CYP2D6 inhibition. Compound 13 (BACE1 IC50=110 nM) demonstrated a reduction in CSF Aß in wild type rats after a single dose.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Benzopiranos/farmacología , Oxazoles/farmacología , Inhibidores de Proteasas/farmacología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Péptidos beta-Amiloides/líquido cefalorraquídeo , Animales , Ácido Aspártico Endopeptidasas/metabolismo , Benzopiranos/síntesis química , Benzopiranos/química , Relación Dosis-Respuesta a Droga , Humanos , Microsomas Hepáticos/enzimología , Conformación Molecular , Oxazoles/síntesis química , Oxazoles/química , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/química , Ratas , Relación Estructura-Actividad , PorcinosRESUMEN
The discovery and optimization of a series of 6,7-dihydro-5H-cyclopenta[d]pyrimidine compounds that are ATP-competitive, selective inhibitors of protein kinase B/Akt is reported. The initial design and optimization was guided by the use of X-ray structures of inhibitors in complex with Akt1 and the closely related protein kinase A. The resulting compounds demonstrate potent inhibition of all three Akt isoforms in biochemical assays and poor inhibition of other members of the cAMP-dependent protein kinase/protein kinase G/protein kinase C extended family and block the phosphorylation of multiple downstream targets of Akt in human cancer cell lines. Biological studies with one such compound, 28 (GDC-0068), demonstrate good oral exposure resulting in dose-dependent pharmacodynamic effects on downstream biomarkers and a robust antitumor response in xenograft models in which the phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin pathway is activated. 28 is currently being evaluated in human clinical trials for the treatment of cancer.
Asunto(s)
Adenosina Trifosfato/metabolismo , Unión Competitiva , Descubrimiento de Drogas , Piperazinas/metabolismo , Piperazinas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pirimidinas/metabolismo , Pirimidinas/farmacología , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Humanos , Concentración 50 Inhibidora , Modelos Moleculares , Piperazinas/química , Conformación Proteica , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/química , Pirimidinas/química , Especificidad por SustratoRESUMEN
The protein serine-threonine kinase Akt undergoes a substantial conformational change upon activation, which is induced by the phosphorylation of two critical regulatory residues, threonine 308 and serine 473. Paradoxically, treating cells with adenosine 5'-triphosphate (ATP)-competitive inhibitors of Akt results in increased phosphorylation of both residues. We show that binding of ATP-competitive inhibitors stabilized a conformation in which both phosphorylated sites were inaccessible to phosphatases. ATP binding also produced this protection of the phosphorylated sites, whereas interaction with its hydrolysis product adenosine 5'-diphosphate (ADP) or allosteric Akt inhibitors resulted in increased accessibility of these phosphorylated residues. ATP-competitive inhibitors mimicked ATP by targeting active Akt. Forms of Akt activated by an oncogenic mutation or myristoylation were more potently inhibited by the ATP-competitive inhibitors than was wild-type Akt. These data support a new model of kinase regulation, wherein nucleotides modulate an on-off switch in Akt through conformational changes, which is disrupted by ATP-competitive inhibitors.
Asunto(s)
Adenosina Trifosfato/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Adenosina Difosfato/metabolismo , Regulación Alostérica , Sitios de Unión , Modelos Moleculares , FosforilaciónRESUMEN
We describe the design and synthesis of novel bicyclic spiro sulfonamides as potent Akt inhibitors. Through structure-based rational design, we have successfully improved PKA selectivity of previously disclosed spirochromanes. Representative compounds showed favorable Akt potency while exhibiting up to 1000-fold selectivity against PKA.
Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/química , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Compuestos de Espiro/química , Sulfonamidas/química , Sitios de Unión , Simulación por Computador , Cristalografía por Rayos X , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Evaluación Preclínica de Medicamentos , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Relación Estructura-Actividad , Sulfonamidas/síntesis química , Sulfonamidas/farmacologíaRESUMEN
A novel series of spirochromane pan-Akt inhibitors is reported. SAR optimization furnished compounds with improved enzyme potencies and excellent selectivity over the related AGC kinase PKA. Attempted replacement of the phenol hinge binder provided compounds with excellent Akt enzyme and cell activities but greatly diminished selectivity over PKA.
Asunto(s)
Inhibidores de Proteínas Quinasas/química , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Sitios de Unión , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Relación Estructura-ActividadRESUMEN
Herein we report the discovery and synthesis of a novel series of dihydrothieno- and dihydrofuropyrimidines (2 and 3) as potent pan Akt inhibitors. Utilizing previous SAR and analysis of the amino acid sequences in the binding site we have designed inhibitors displaying increased PKA and general kinase selectivity with improved tolerability compared to the progenitor pyrrolopyrimidine (1). A representative dihydrothieno compound (34) was advanced into a PC3-NCI prostate mouse tumor model in which it demonstrated a dose-dependent reduction in tumor growth and stasis when dosed orally daily at 200 mg/kg.
Asunto(s)
Neoplasias de la Próstata/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/química , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Pirimidinas/química , Animales , Sitios de Unión , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Masculino , Ratones , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Relación Estructura-Actividad , Carga Tumoral/efectos de los fármacosRESUMEN
AKT1 (NP_005154.2) is a member of the serine/threonine AGC protein kinase family involved in cellular metabolism, growth, proliferation and survival. The three human AKT isozymes are highly homologous multi-domain proteins with both overlapping and distinct cellular functions. Dysregulation of the AKT pathway has been identified in multiple human cancers. Several clinical trials are in progress to test the efficacy of AKT pathway inhibitors in treating cancer. Recently, a series of AKT isozyme-selective allosteric inhibitors have been reported. They require the presence of both the pleckstrin-homology (PH) and kinase domains of AKT, but their binding mode has not yet been elucidated. We present here a 2.7 Å resolution co-crystal structure of human AKT1 containing both the PH and kinase domains with a selective allosteric inhibitor bound in the interface. The structure reveals the interactions between the PH and kinase domains, as well as the critical amino residues that mediate binding of the inhibitor to AKT1. Our work also reveals an intricate balance in the enzymatic regulation of AKT, where the PH domain appears to lock the kinase in an inactive conformation and the kinase domain disrupts the phospholipid binding site of the PH domain. This information advances our knowledge in AKT1 structure and regulation, thereby providing a structural foundation for interpreting the effects of different classes of AKT inhibitors and designing selective ones.
Asunto(s)
Regulación hacia Abajo , Inhibidores Enzimáticos/química , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/química , Regulación Alostérica , Secuencia de Aminoácidos , Sitios de Unión , Cristalografía por Rayos X , Inhibidores Enzimáticos/metabolismo , Humanos , Conformación Molecular , Datos de Secuencia Molecular , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
The discovery and optimization of a series of pyrrolopyrimidine based protein kinase B (Pkb/Akt) inhibitors discovered via HTS and structure based drug design is reported. The compounds demonstrate potent inhibition of all three Akt isoforms and knockdown of phospho-PRAS40 levels in LNCaP cells and tumor xenografts.
Asunto(s)
Inhibidores de Proteínas Quinasas/química , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Pirimidinas/química , Pirroles/química , Proteínas Adaptadoras Transductoras de Señales , Animales , Sitios de Unión , Línea Celular , Cristalografía por Rayos X , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Ensayos Analíticos de Alto Rendimiento , Humanos , Ratones , Fosfoproteínas/deficiencia , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/metabolismo , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pirimidinas/síntesis química , Pirimidinas/farmacología , Pirroles/síntesis química , Pirroles/farmacología , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Several docking programs are now available that can reproduce the bound conformation of a ligand in an active site, for a wide variety of experimentally determined complexes. However, these programs generally perform less well at ranking multiple possible ligands in one site. Since accurate identification of potential ligands is a prerequisite for many aspects of structure-based drug design, this is a serious limitation. We have tested the ability of two docking programs, FlexX and Gold, to match ligands and active sites for multiple complexes. We show that none of the docking scores from either program are able to match consistently ligands and active sites in our tests. We propose a simple statistical correction, the multiple active site correction (MASC), which greatly ameliorates this problem. We have also tested the correction method against an extended set of 63 cocrystals and in a virtual screening experiment. In all cases, MASC significantly improves the results of the docking experiments.