RESUMEN
Cancer cells reprogram their metabolism to support growth and to mitigate cellular stressors. The serine synthesis pathway has been identified as a metabolic pathway frequently altered in cancers and there has been considerable interest in developing pharmacological agents to target this pathway. Here, we report a series of indole amides that inhibit human 3-phosphoglycerate dehydrogenase (PHGDH), the enzyme that catalyzes the first committed step of the serine synthesis pathway. Using X-ray crystallography, we show that the indole amides bind the NAD+ pocket of PHGDH. Through structure-based optimization we were able to develop compounds with low nanomolar affinities for PHGDH in an enzymatic IC50 assay. In cellular assays, the most potent compounds inhibited de novo serine synthesis with low micromolar to sub-micromolar activities and these compounds successfully abrogated the proliferation of cancer cells in serine free media. The indole amide series reported here represent an important improvement over previously published PHGDH inhibitors as they are markedly more potent and their mechanism of action is better defined.
Asunto(s)
Amidas/química , Inhibidores Enzimáticos/química , Indoles/química , Fosfoglicerato-Deshidrogenasa/antagonistas & inhibidores , Serina/biosíntesis , Amidas/metabolismo , Amidas/farmacología , Sitios de Unión , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Humanos , Simulación de Dinámica Molecular , Fosfoglicerato-Deshidrogenasa/metabolismo , Estructura Terciaria de Proteína , Relación Estructura-ActividadRESUMEN
Phosphorylation of inhibitor of nuclear transcription factor κB (IκB) by IκB kinase (IKK) triggers the degradation of IκB and migration of cytoplasmic κB to the nucleus where it promotes the transcription of its target genes. Activation of IKK is achieved by phosphorylation of its main subunit, IKKß, at the activation loop sites. Here, we report the 2.8 Å resolution crystal structure of human IKKß (hIKKß), which is partially phosphorylated and bound to the staurosporine analog K252a. The hIKKß protomer adopts a trimodular structure that closely resembles that from Xenopus laevis (xIKKß): an N-terminal kinase domain (KD), a central ubiquitin-like domain (ULD), and a C-terminal scaffold/dimerization domain (SDD). Although hIKKß and xIKKß utilize a similar dimerization mode, their overall geometries are distinct. In contrast to the structure resembling closed shears reported previously for xIKKß, hIKKß exists as an open asymmetric dimer in which the two KDs are further apart, with one in an active and the other in an inactive conformation. Dimer interactions are limited to the C-terminal six-helix bundle that acts as a hinge between the two subunits. The observed domain movements in the structures of IKKß may represent trans-phosphorylation steps that accompany IKKß activation.
Asunto(s)
Quinasa I-kappa B/química , Cristalización , Cristalografía por Rayos X , Dimerización , Humanos , Quinasa I-kappa B/antagonistas & inhibidores , Quinasa I-kappa B/metabolismo , Ligandos , Modelos Moleculares , FosforilaciónRESUMEN
The immunoglobulin new antigen receptors (IgNARs) are a class of Ig-like molecules of the shark immune system that exist as heavy chain-only homodimers and bind antigens by their single domain variable regions (V-NARs). Following shark immunization and/or in vitro selection, V-NARs can be generated as soluble, stable, and specific high affinity monomeric binding proteins of â¼12 kDa. We have previously isolated a V-NAR from an immunized spiny dogfish shark, named E06, that binds specifically and with high affinity to human, mouse, and rat serum albumins. Humanization of E06 was carried out by converting over 60% of non-complementarity-determining region residues to those of a human germ line Vκ1 sequence, DPK9. The resulting huE06 molecules have largely retained the specificity and affinity of antigen binding of the parental V-NAR. Crystal structures of the shark E06 and its humanized variant (huE06 v1.1) in complex with human serum albumin (HSA) were determined at 3- and 2.3-Å resolution, respectively. The huE06 v1.1 molecule retained all but one amino acid residues involved in the binding site for HSA. Structural analysis of these V-NARs has revealed an unusual variable domain-antigen interaction. E06 interacts with HSA in an atypical mode that utilizes extensive framework contacts in addition to complementarity-determining regions that has not been seen previously in V-NARs. On the basis of the structure, the roles of various elements of the molecule are described with respect to antigen binding and V-NAR stability. This information broadens the general understanding of antigen recognition and provides a framework for further design and humanization of shark IgNARs.
Asunto(s)
Anticuerpos Monoclonales Humanizados/química , Tiburones/inmunología , Anticuerpos de Cadena Única/química , Secuencia de Aminoácidos , Animales , Células COS , Chlorocebus aethiops , Cristalografía por Rayos X , Proteínas de Peces , Humanos , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Unión Proteica , Ingeniería de Proteínas , Estructura Cuaternaria de Proteína , Estructura Secundaria de Proteína , Ratas , Homología de Secuencia de Aminoácido , Albúmina Sérica/químicaRESUMEN
Inhibition of Hepatitis B Virus (HBV) replication by small molecules that modulate capsid assembly and the encapsidation of pgRNA and viral polymerase by HBV core protein is a clinically validated approach toward the development of new antivirals. Through definition of a minimal pharmacophore, a series of isoquinolinone-based capsid assembly modulators (CAMs) was identified. Structural biology analysis revealed that lead molecules possess a unique binding mode, exploiting electrostatic interactions with accessible phenylalanine and tyrosine residues. Key analogs demonstrated excellent primary potency, absorption, distribution, metabolism, and excretion (ADME) and pharmacokinetic properties, and efficacy in a mouse model of HBV. The optimized lead also displayed potent inhibition of capsid uncoating in HBV-infected HepG2 cells expressing the sodium-taurocholate cotransporting polypeptide (NTCP) receptor, affecting the generation of HBsAg and cccDNA establishment. Based on these results, isoquinolinone derivative AB-836 was advanced into clinical development. In Phase 1b trials, AB-836 demonstrated >3 log10 reduction in serum HBV DNA, however, further development was discontinued due to the observation of incidental alanine aminotransferase (ALT) elevations.
Asunto(s)
Antivirales , Diseño de Fármacos , Virus de la Hepatitis B , Humanos , Relación Estructura-Actividad , Virus de la Hepatitis B/efectos de los fármacos , Animales , Antivirales/farmacología , Antivirales/síntesis química , Antivirales/química , Antivirales/farmacocinética , Ratones , Células Hep G2 , Cápside/efectos de los fármacos , Cápside/metabolismo , Proteínas de la Cápside/metabolismo , Proteínas de la Cápside/antagonistas & inhibidores , Isoquinolinas/farmacología , Isoquinolinas/química , Isoquinolinas/síntesis química , Quinolonas/farmacología , Quinolonas/síntesis química , Quinolonas/química , Ensamble de Virus/efectos de los fármacosRESUMEN
Disruption of the HBV viral life cycle with small molecules that prevent the encapsidation of pregenomic RNA and viral polymerase through binding to HBV core protein is a clinically validated approach to inhibiting HBV viral replication. Herein we report the further optimisation of clinical candidate AB-506 through core modification with a focus on increasing oral exposure and oral half-life. Maintenance of high levels of anti-HBV cellular potency in conjunction with improvements in pharmacokinetic properties led to multi-log10 reductions in serum HBV DNA following low, once-daily oral dosing for key analogues in a preclinical animal model of HBV replication.
RESUMEN
An extension of our previously reported series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. Addition of a second methyl group to the tether provided analogs that show increased potency in binding as well as cell-proliferation assays and, more importantly, are stable toward microsomes. We wish to disclose the discovery of a macrocycle which showed impressive biomarker activity 24-h post dosing and which demonstrated prolonged exposure in tumors. When studied in a lung cancer xenograft model, the compound demonstrated significant tumor size reduction.
Asunto(s)
Antineoplásicos/química , Benzamidas/química , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Neoplasias Pulmonares/tratamiento farmacológico , Compuestos Macrocíclicos/química , Administración Oral , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Benzamidas/farmacocinética , Benzamidas/uso terapéutico , Sitios de Unión , Biomarcadores/metabolismo , Evaluación Preclínica de Medicamentos , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Ratones , Ratones Desnudos , Microsomas Hepáticos/metabolismo , Estructura Terciaria de Proteína , Ratas , Trasplante HeterólogoRESUMEN
To further elucidate the mechanism of action and binding properties of eptinezumab to calcitonin gene-related peptide (CGRP), X-ray crystallography, computational alanine scanning, and molecular dynamics were used. X-ray diffraction data were collected to determine the three-dimensional structures of the unbound eptinezumab antigen-binding fragment (Fab) and the Fab:CGRP complex. Molecular dynamics simulations were performed to analyze the transition between uncomplexed and complex states. The amidated C-terminus of CGRP was shown to bind in a pocket formed by the Fab heavy and light chains. There was extensive contact between all six complementarity-determining regions (CDRs; composed of light-chain [L1, L2, and L3] and heavy-chain [H1, H2, H3]) of eptinezumab and CGRP. The complex demonstrated a high ligand-binding surface area dominated by aromatic residues. CDR L3 contains a disulfide bond that stabilizes the loop, contributes surface area to the binding pocket, and provides van der Waals contacts. Comparison of the uncomplexed and complex structures revealed motion near the binding cleft. The CDR loops H2 and H3 were displaced ~1.4-2.0 Å and residue H-Tyr33 changed conformation, creating a 'latch-and-lock' mechanism for binding CGRP and preventing dissociation. Computational alanine scanning of CGRP identified energetic 'hot spots' that contribute to binding energy; mutating these positions to residues in homologous neuropeptides resulted in unfavorable binding energies. The attributes of the Fab region and the conformational changes that occur in eptinezumab during binding to CGRP contribute to the specificity, durability, and strength of the interaction, and likely underlie the rapid and sustained migraine preventive effect observed in clinical studies.
Asunto(s)
Anticuerpos Monoclonales Humanizados/química , Péptido Relacionado con Gen de Calcitonina/química , Epítopos/química , Humanos , Enlace de Hidrógeno , Modelos Moleculares , Unión Proteica , Conformación Proteica , Estabilidad Proteica , Agua/química , Difracción de Rayos XRESUMEN
A novel class of pyridinyl aminohydantoins was designed and prepared as highly potent BACE1 inhibitors. Compound (S)-4g showed excellent potency with IC(50) of 20 nM for BACE1. X-ray crystallography indicated that the interaction between pyridine nitrogen and the tryptophan Trp76 was a key feature in the S2' region of the enzyme that contributed to increased potency.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/metabolismo , Hidantoínas/farmacología , Piridinas/farmacología , Secretasas de la Proteína Precursora del Amiloide/química , Ácido Aspártico Endopeptidasas/química , Cristalografía por Rayos X , Humanos , Hidantoínas/química , Modelos Moleculares , Unión Proteica , Piridinas/química , Relación Estructura-ActividadRESUMEN
The identification of small molecule aminohydantoins as potent and selective human ß-secretase inhibitors is reported. These analogs exhibit good brain permeability (40-70%), low nanomolar potency for BACE1, and demonstrate >100-fold selectivity for the structurally related aspartyl proteases cathepsin D, renin and pepsin. Alkyl and alkoxy groups at the meta-position of the P1 phenyl, which extend toward the S3 region of the enzyme, have contributed to the ligand's reduced affinity for the efflux transporter protein P-gp, and decreased topological polar surface area, thus resulting in enhanced brain permeability. A fluorine substitution at the para-position of the P1 phenyl has contributed to 100-fold decrease of CYP3A4 inhibition and enhancement of compound metabolic stability. The plasma and brain protein binding properties of these new analogs are affected by substitutions at the P1 phenyl moiety. Higher compound protein binding was observed in the brain than in the plasma. Two structurally diverse potent BACE1 inhibitors (84 and 89) reduced 30% plasma Aß40 in the Tg2576 mice in vivo model at 30 mg/kg p.o..
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Encéfalo/metabolismo , Inhibidores Enzimáticos/síntesis química , Hidantoínas/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Hidantoínas/química , Hidantoínas/farmacología , PermeabilidadRESUMEN
A series of 4-(3-aryloxyaryl)quinolines with sulfone substituents on the terminal aryl ring (7) was prepared as LXR agonists. High affinity LXR ligands with excellent agonist potency and efficacy in functional assays of LXR activity were identified. In general, these sulfone agonists were equal to or superior to previously described alcohol and amide analogs in terms of affinity, functional potency, and microsomal stability. Many of the sulfones had LXRbeta binding IC(50) values <10nM while the most potent compounds in an ABCA1 mRNA induction assay in J774 mouse cells had EC(50) values <10nM and were as efficacious as T0901317.
Asunto(s)
Receptores Nucleares Huérfanos/agonistas , Quinolinas/química , Sulfonas/química , Transportador 1 de Casete de Unión a ATP , Transportadoras de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Sitios de Unión , Línea Celular , Simulación por Computador , Humanos , Hidrocarburos Fluorados/química , Hidrocarburos Fluorados/farmacología , Enlace de Hidrógeno , Receptores X del Hígado , Ratones , Microsomas Hepáticos/metabolismo , Receptores Nucleares Huérfanos/metabolismo , Quinolinas/síntesis química , Quinolinas/farmacología , Ratas , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacología , Sulfonas/síntesis química , Sulfonas/farmacologíaRESUMEN
The proteolytic enzyme beta-secretase (BACE1) plays a central role in the synthesis of the pathogenic beta-amyloid in Alzheimer's disease. Recently, we reported small molecule acylguanidines as potent BACE1 inhibitors. However, many of these acylguanidines have a high polar surface area (e.g. as measured by the topological polar surface area or TPSA), which is unfavorable for crossing the blood-brain barrier. Herein, we describe the identification of the 2-aminopyridine moiety as a bioisosteric replacement of the acylguanidine moiety, which resulted in inhibitors with lower TPSA values and superior brain penetration. X-ray crystallographic studies indicated that the 2-aminopyridine moiety interacts directly with the catalytic aspartic acids Asp32 and Asp228 via a hydrogen-bonding network.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Aminopiridinas/química , Aminopiridinas/farmacocinética , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/metabolismo , Encéfalo/metabolismo , Enfermedad de Alzheimer/enzimología , Aminopiridinas/farmacología , Secretasas de la Proteína Precursora del Amiloide/química , Ácido Aspártico Endopeptidasas/química , Cristalografía por Rayos X , Humanos , Modelos Moleculares , Relación Estructura-ActividadRESUMEN
The identification of highly selective small molecule di-substituted pyridinyl aminohydantoins as beta-secretase inhibitors is reported. The more potent and selective analogs demonstrate low nanomolar potency for the BACE1 enzyme as measured in a FRET assay, and exhibit comparable activity in a cell-based (ELISA) assay. In addition, these pyridine-aminohydantoins are highly selectivity (>500x) against the other structurally related aspartyl proteases BACE2, cathepsin D, pepsin and renin. Our design strategy followed a traditional SAR approach and was supported by molecular modeling studies based on the previously reported aminohydantoin 3a. We have taken advantage of the amino acid difference between the BACE1 and BACE2 at the S2' pocket (BACE1 Pro(70) changed to BACE2 Lys(86)) to build ligands with >500-fold selectivity against BACE2. The addition of large substituents on the targeted ligand at the vicinity of this aberration has generated a steric conflict between the ligand and these two proteins, thus impacting the ligand's affinity and selectivity. These ligands have also shown an exceptional selectivity against cathepsin D (>5000-fold) as well as the other aspartyl proteases mentioned. One of the more potent compounds (S)-39 displayed an IC(50) value for BACE1 of 10nM, and exhibited cellular activity with an EC(50) value of 130nM in the ELISA assay.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Hidantoínas/farmacología , Piridinas/farmacología , Cristalografía por Rayos X , Humanos , Hidantoínas/síntesis química , Hidantoínas/química , Ligandos , Modelos Moleculares , Estructura Molecular , Peso Molecular , Piridinas/síntesis química , Piridinas/química , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Cancer cachexia is a highly prevalent condition associated with poor quality of life and reduced survival1. Tumor-induced perturbations in the endocrine, immune and nervous systems drive anorexia and catabolic changes in adipose tissue and skeletal muscle, hallmarks of cancer cachexia2-4. However, the molecular mechanisms driving cachexia remain poorly defined, and there are currently no approved drugs for the condition. Elevation in circulating growth differentiation factor 15 (GDF15) correlates with cachexia and reduced survival in patients with cancer5-8, and a GDNF family receptor alpha like (GFRAL)-Ret proto-oncogene (RET) signaling complex in brainstem neurons that mediates GDF15-induced weight loss in mice has recently been described9-12. Here we report a therapeutic antagonistic monoclonal antibody, 3P10, that targets GFRAL and inhibits RET signaling by preventing the GDF15-driven interaction of RET with GFRAL on the cell surface. Treatment with 3P10 reverses excessive lipid oxidation in tumor-bearing mice and prevents cancer cachexia, even under calorie-restricted conditions. Mechanistically, activation of the GFRAL-RET pathway induces expression of genes involved in lipid metabolism in adipose tissues, and both peripheral chemical sympathectomy and loss of adipose triglyceride lipase protect mice from GDF15-induced weight loss. These data uncover a peripheral sympathetic axis by which GDF15 elicits a lipolytic response in adipose tissue independently of anorexia, leading to reduced adipose and muscle mass and function in tumor-bearing mice.
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Caquexia/tratamiento farmacológico , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Factor 15 de Diferenciación de Crecimiento/genética , Complejos Multiproteicos/ultraestructura , Neoplasias/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-ret/genética , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Anticuerpos Monoclonales , Caquexia/complicaciones , Caquexia/genética , Caquexia/inmunología , Línea Celular Tumoral , Cristalografía por Rayos X , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/ultraestructura , Factor 15 de Diferenciación de Crecimiento/ultraestructura , Xenoinjertos , Humanos , Peroxidación de Lípido , Ratones , Complejos Multiproteicos/genética , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/patología , Neoplasias/complicaciones , Neoplasias/genética , Neoplasias/inmunología , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-ret/ultraestructura , Transducción de Señal , Pérdida de PesoRESUMEN
A series of substituted benzo[c][2,7]-naphthyridines were prepared and showed good potency in inhibiting PDK-1. The synthesis and SAR of this series of compounds are presented as well as the X-ray crystal structure of one of these analogs in a complex with PDK-1.
Asunto(s)
Antineoplásicos/química , Naftiridinas/química , Inhibidores de Proteínas Quinasas/química , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Quinasas Dependientes de 3-Fosfoinosítido , Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Sitios de Unión , Cristalografía por Rayos X , Humanos , Conformación Molecular , Naftiridinas/síntesis química , Naftiridinas/farmacología , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Relación Estructura-ActividadRESUMEN
Proteolytic cleavage of amyloid precursor protein by beta-secretase (BACE-1) and gamma-secretase leads to formation of beta-amyloid (A beta) a key component of amyloid plaques, which are considered the hallmark of Alzheimer's disease. Small molecule inhibitors of BACE-1 may reduce levels of A beta and thus have therapeutic potential for treating Alzheimer's disease. We recently reported the identification of a novel small molecule BACE-1 inhibitor N-[2-(2,5-diphenyl-pyrrol-1-yl)-acetyl]guanidine (3.a.1). We report here the initial hit-to-lead optimization of this hit and the SAR around the aryl groups occupying the S(1) and S(2') pockets leading to submicromolar BACE-1 inhibitors.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Péptidos beta-Amiloides/metabolismo , Técnicas Químicas Combinatorias , Guanidinas/síntesis química , Guanidinas/farmacología , Pirroles/química , Cristalografía por Rayos X , Guanidinas/química , Conformación Molecular , Estructura Molecular , Pirroles/farmacología , Relación Estructura-ActividadRESUMEN
With high-throughput screening, substituted dibenzo[c,f][2,7]naphthyridine 1 was identified as a novel potent and selective phosphoinositide-dependent kinase-1 (PDK-1) inhibitor. Various regions of the lead molecule were explored to understand the SAR requirement for this scaffold. The crystal structure of 1 with kinase domain of PDK-1 confirmed the binding in the active site. The key interaction of the molecule with the active site residues, observed SAR, and the biological profile are discussed in detail.
Asunto(s)
Naftiridinas/síntesis química , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Quinasas Dependientes de 3-Fosfoinosítido , Sitios de Unión , Cristalografía por Rayos X , Modelos Moleculares , Estructura Molecular , Naftiridinas/química , Proteínas Serina-Treonina Quinasas/química , Relación Estructura-ActividadRESUMEN
Tanaproget represents a potential first-in-class nonsteroidal PR agonist for contraception with improved safety and side effect profiles versus currently available steroidal oral contraceptives. Additional SAR, biological activity, and structural information from a tanaproget/hPR-LBD (hPR-LBD = human progesterone receptor ligand binding domain) cocrystal structure will also be presented.
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Benzoxazinas/síntesis química , Oxazinas/síntesis química , Pirroles/síntesis química , Receptores de Progesterona/agonistas , Tionas/síntesis química , Fosfatasa Alcalina/metabolismo , Animales , Área Bajo la Curva , Benzoxazinas/química , Benzoxazinas/farmacología , Unión Competitiva , Línea Celular Tumoral , Anticonceptivos Femeninos/síntesis química , Anticonceptivos Femeninos/química , Anticonceptivos Femeninos/farmacología , Decidua/efectos de los fármacos , Decidua/metabolismo , Femenino , Semivida , Humanos , Técnicas In Vitro , Ligandos , Estructura Molecular , Oxazinas/química , Oxazinas/farmacología , Estructura Terciaria de Proteína , Pirroles/química , Pirroles/farmacología , Ratas , Ratas Sprague-Dawley , Receptores de Progesterona/antagonistas & inhibidores , Receptores de Progesterona/química , Relación Estructura-Actividad , Tionas/química , Tionas/farmacologíaRESUMEN
A series of 8,9-dimethoxy-5-(2-aminoalkoxy-pyridin-3-yl)-benzo[c][2,7]naphthyridin-4-ylamine-based inhibitors of 3-phosphoinositide-dependent kinase-1 (PDK-1) has been identified. Several examples appear to be potent and relatively selective inhibitors of PDK-1 over the related AGC kinases PKA, PKB/AKT, and p70S6K. The introduction of a stereochemical center beside the amino substituent on the aminoalkoxy-side chain had little effect upon the inhibitory activity against these enzymes, and X-ray crystallographic analyses of a representative pair of enantiomeric inhibitors bound to the active site of PDK-1 revealed comparable binding modes for each enantiomer.
Asunto(s)
Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Piridinas/farmacología , Proteínas Quinasas Dependientes de 3-Fosfoinosítido , Cristalografía por Rayos X , Enlace de Hidrógeno , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteínas Quinasas/química , Piridinas/química , Electricidad Estática , Relación Estructura-ActividadRESUMEN
The identification of small molecule aminohydantoins as potent and selective human beta-secretase inhibitors is reported. These analogues exhibit low nannomolar potency for BACE1, show comparable activity in a cell-based (ELISA) assay, and demonstrate >100x selectivity for the other structurally related aspartyl proteases BACE2, cathepsinD, renin, and pepsin. On the basis of the cocrystal structure of the HTS-hit 2 in the BACE1 active site and by use of a structure-based drug design approach, we methodically explored the comparatively large binding pocket of the BACE1 enzyme and identified key interactions between the ligand and the protein that contributed to the affinity. One of the more potent compounds, (S)-55, displayed an IC(50) value for BACE1 of 10 nM and exhibited comparable cellular activity (EC(50) = 20 nM) in the ELISA assay. Acute oral administration of (S)-55 at 100 mg/kg resulted in a 69% reduction of plasma A beta(40) at 8 h in a Tg2576 mouse (p < 0.001).
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Diseño de Fármacos , Hidantoínas/química , Inhibidores de Proteasas/química , Inhibidores de Proteasas/síntesis química , Animales , Células CHO , Cricetinae , Cricetulus , Cristalografía por Rayos X , Humanos , Enlace de Hidrógeno , Ratones , Mitocondrias/efectos de los fármacos , Modelos Químicos , Estructura Molecular , Inhibidores de Proteasas/farmacología , Relación Estructura-ActividadRESUMEN
Acidic mammalian chitinase (AMCase) is a member of the glycosyl hydrolase 18 family (EC 3.2.1.14) that has been implicated in the pathophysiology of allergic airway disease such as asthma. Small molecule inhibitors of AMCase were identified using a combination of high-throughput screening, fragment screening, and virtual screening techniques and characterized by enzyme inhibition and NMR and Biacore binding experiments. X-ray structures of the inhibitors in complex with AMCase revealed that the larger more potent HTS hits, e.g. 5-(4-(2-(4-bromophenoxy)ethyl)piperazine-1-yl)-1H-1,2,4-triazol-3-amine 1, spanned from the active site pocket to a hydrophobic pocket. Smaller fragments identified by FBS occupy both these pockets independently and suggest potential strategies for linking fragments. Compound 1 is a 200 nM AMCase inhibitor which reduced AMCase enzymatic activity in the bronchoalveolar lavage fluid in allergen-challenged mice after oral dosing.