RESUMO
G-protein coupled receptor kinase 2 (GRK2), which is upregulated in the failing heart, appears to play a critical role in heart failure (HF) progression in part because enhanced GRK2 activity promotes dysfunction of ß-adrenergic signaling and myocyte death. An orally bioavailable GRK2 inhibitor could offer unique therapeutic outcomes that cannot be attained by current heart failure treatments that directly target GPCRs or angiotensin-converting enzyme. Herein, we describe the discovery of a potent, selective, and orally bioavailable GRK2 inhibitor, 8h, through high-throughput screening, hit-to-lead optimization, structure-based design, molecular modelling, synthesis, and biological evaluation. In the cellular target engagement assays, 8h enhances isoproterenol-mediated cyclic adenosine 3',5'-monophosphate (cAMP) production in HEK293 cells overexpressing GRK2. Compound 8h was further evaluated in a human stem cell-derived cardiomyocyte (HSC-CM) contractility assay and potentiated isoproterenol-induced beating rate in HSC-CMs.
Assuntos
Quinase 2 de Receptor Acoplado a Proteína G/antagonistas & inibidores , Ftalazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Animais , Ensaios Enzimáticos , Quinase 2 de Receptor Acoplado a Proteína G/metabolismo , Células HEK293 , Humanos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Estrutura Molecular , Miócitos Cardíacos/efeitos dos fármacos , Ftalazinas/síntese química , Ftalazinas/farmacocinética , Ligação Proteica , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , Quinazolinas/síntese química , Quinazolinas/metabolismo , Quinazolinas/farmacocinética , Relação Estrutura-AtividadeRESUMO
The introduction of thermostable polymerases revolutionized the polymerase chain reaction (PCR) and biotechnology. However, many GC-rich genes cannot be PCR-amplified with high efficiency in water, irrespective of temperature. Although polar organic cosolvents can enhance nucleic acid polymerization and amplification by destabilizing duplex DNA and secondary structures, nature has not selected for the evolution of solvent-tolerant polymerase enzymes. Here, we used ultrahigh-throughput droplet-based selection and deep sequencing along with computational free-energy and binding affinity calculations to evolve Taq polymerase to generate enzymes that are both stable and highly active in the presence of organic cosolvents, resulting in up to 10% solvent resistance and over 100-fold increase in stability at 97.5 °C in the presence of 1,4-butanediol, as well as tolerance to up to 10 times higher concentrations of the potent cosolvents sulfolane and 2-pyrrolidone. Using these polymerases, we successfully amplified a broad spectrum of GC-rich templates containing regions with over 90% GC content, including templates recalcitrant to amplification with existing polymerases, even in the presence of cosolvents. We also demonstrated dramatically reduced GC bias in the amplification of genes with widely varying GC content in quantitative polymerase chain reaction (qPCR). By expanding the scope of solvent systems compatible with nucleic acid polymerization, these organic solvent-resistant polymerases enable a dramatic reduction of sequence bias not achievable through thermal resistance alone, with significant implications for a wide range of applications including sequencing and synthetic biology in mixed aqueous-organic media.
Assuntos
DNA Polimerase Dirigida por DNA , DNA , DNA Polimerase Dirigida por DNA/metabolismo , DNA/genética , Reação em Cadeia da Polimerase/métodos , Composição de Bases , SolventesRESUMO
Diacylglycerol acyltransferase (DGAT) catalyzes the final step in triglyceride (TG) synthesis. There are two isoforms, DGAT1 and DGAT2, with distinct protein sequences and potentially different physiological functions. To date, the ability to determine clear functional differences between DGAT1 and DGAT2, especially with respect to hepatic TG synthesis, has been elusive. To dissect the roles of these two key enzymes, we pretreated HepG2 hepatoma cells with (13)C(3)-D(5)-glycerol or (13)C(18)-oleic acid, and profiled the major isotope-labeled TG species by liquid chromatography tandem mass spectrometry. Selective DGAT1 and DGAT2 inhibitors demonstrated that (13)C(3)-D(5)-glycerol-incorporated TG synthesis was mediated by DGAT2, not DGAT1. Conversely, (13)C(18)-oleoyl-incorporated TG synthesis was predominantly mediated by DGAT1. To trace hepatic TG synthesis and VLDL triglyceride (VLDL-TG) secretion in vivo, we administered D(5)-glycerol to mice and measured plasma levels of D(5)-glycerol-incorporated TG. Treatment with an antisense oligonucleotide (ASO) to DGAT2 led to a significant reduction in D(5)-glycerol incorporation into VLDL-TG. In contrast, the DGAT2 ASO had no effect on the incorporation of exogenously administered (13)C(18)-oleic acid into VLDL-TG. Thus, our results indicate that DGAT1 and DGAT2 mediate distinct hepatic functions: DGAT2 is primarily responsible for incorporating endogenously synthesized FAs into TG, whereas DGAT1 plays a greater role in esterifying exogenous FAs to glycerol.
Assuntos
Diacilglicerol O-Aciltransferase/metabolismo , Ensaios Enzimáticos/métodos , Glicerol/metabolismo , Fígado/enzimologia , Ácido Oleico/metabolismo , Animais , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Diacilglicerol O-Aciltransferase/genética , Inibidores Enzimáticos/farmacologia , Esterificação/efeitos dos fármacos , Ácidos Graxos/biossíntese , Ácidos Graxos/metabolismo , Células Hep G2 , Humanos , Marcação por Isótopo , Lipoproteínas VLDL/metabolismo , Masculino , Camundongos , Oligonucleotídeos Antissenso/genética , Triglicerídeos/biossínteseRESUMO
During efforts to improve the bioavailability of FMS kinase inhibitors 1 and 2, a series of saturated and aromatic 4-heterocycles of reduced basicity were prepared and evaluated in an attempt to also improve the cardiovascular safety profile over lead arylamide 1, which possessed ion channel activity. The resultant compounds retained excellent potency and exhibited diminished ion channel activity.
Assuntos
Amidas/farmacologia , Compostos Heterocíclicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Relação Dose-Resposta a Droga , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Modelos Moleculares , Estrutura Molecular , Oxirredução , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
A series of pyrimidinopyridones has been designed, synthesized and shown to be potent and selective inhibitors of the FMS tyrosine kinase. Introduction of an amide substituent at the 6-position of the pyridone core resulted in a significant potency increase. Compound 24 effectively inhibited in vivo LPS-induced TNF in mice greater than 80%.
Assuntos
Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Desenho de Fármacos , Inibidores de Proteínas Quinases/farmacologia , Piridonas/farmacologia , Pirimidinas/farmacologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Amidas/química , Animais , Anti-Inflamatórios/síntese química , Antineoplásicos/síntese química , Lipopolissacarídeos/toxicidade , Camundongos , Modelos Químicos , Inibidores de Proteínas Quinases/síntese química , Piridinas/química , Piridonas/síntese química , Pirimidinas/síntese química , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The optimization of the arylamide lead 2 resulted in identification of a highly potent series of 2,4-disubstituted arylamides. Compound 8 (FMS kinase IC(50)=0.0008 microM) served as a proof-of-concept candidate in a collagen-induced model of arthritis in mice.
Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Animais , Artrite/induzido quimicamente , Artrite/tratamento farmacológico , Colágeno , Relação Dose-Resposta a Droga , Camundongos , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Fatores de TempoRESUMO
A series of 3,4,6-substituted 2-quinolones has been synthesized and evaluated as inhibitors of the kinase domain of macrophage colony-stimulating factor-1 receptor (FMS). The fully optimized compound, 4-(4-ethyl-phenyl)-3-(2-methyl-3H-imidazol-4-yl)-2-quinolone-6-carbonitrile 21b, has an IC(50) of 2.5 nM in an in vitro assay and 5.0 nM in a bone marrow-derived macrophage cellular assay. Inhibition of FMS signaling in vivo was also demonstrated in a mouse pharmacodynamic model.
Assuntos
Macrófagos/efeitos dos fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Quinolonas/síntese química , Quinolonas/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Proliferação de Células/efeitos dos fármacos , Polarização de Fluorescência , Genes fos/genética , Fator Estimulador de Colônias de Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Quinolonas/farmacocinética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Receptor de Fator Estimulador de Colônias de Macrófagos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/metabolismo , Relação Estrutura-AtividadeRESUMO
Monoacylglycerol acyltransferase enzymes (MGAT1, MGAT2, and MGAT3) convert monoacylglycerol to diacylglycerol (DAG). MGAT1 and MGAT2 are both implicated in obesity-related metabolic diseases. Conventional MGAT enzyme assays use radioactive substrates, wherein the product of the MGAT-catalyzed reaction is usually resolved by time-consuming thin layer chromatography (TLC) analysis. Furthermore, microsomal membrane preparations typically contain endogenous diacylglycerol acyltransferase (DGAT) from the host cells, and these DGAT activities can further acylate DAG to form triglyceride (TG). Our mass spectrometry (liquid chromatography-tandem mass spectrometry, or LC/MS/MS) MGAT2 assay measures human recombinant MGAT2-catalyzed formation of didecanoyl-glycerol from 1-decanoyl-rac-glycerol and decanoyl-CoA, to produce predominantly 1,3-didecanoyl-glycerol. Unlike 1,2-DAG, 1,3-didecanoyl-glycerol is proved to be not susceptible to further acylation to TG. 1,3-Didecanoyl-glycerol product can be readily solubilized and directly subjected to high-throughput mass spectrometry (HTMS) without further extraction in a 384-well format. We also have established the LC/MS/MS MGAT activity assay in the intestinal microsomes from various species. Our assay is proved to be highly sensitive, and thus it allows measurement of endogenous MGAT activity in cell lysates and tissue preparations. The implementation of the HTMS MGAT activity assay has facilitated the robust screening and evaluation of MGAT inhibitors for the treatment of metabolic diseases.
Assuntos
Diglicerídeos/análise , Inibidores Enzimáticos/análise , Ensaios de Triagem em Larga Escala , N-Acetilglucosaminiltransferases/antagonistas & inibidores , Acil Coenzima A/metabolismo , Animais , Chlorocebus aethiops , Cromatografia Líquida/métodos , Diglicerídeos/antagonistas & inibidores , Diglicerídeos/biossíntese , Cães , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Haplorrinos , Humanos , Intestinos/efeitos dos fármacos , Intestinos/enzimologia , Cinética , Camundongos , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , N-Acetilglucosaminiltransferases/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/metabolismo , Espectrometria de Massas em Tandem/métodosRESUMO
2-Hydroxy-4,6-diamino-[1,3,5]triazines are described which are a novel class of potent inhibitors of the VEGF-R2 (flk-1/KDR) tyrosine kinase. 4-(Benzothiazol-6-ylamino)-6-(benzyl-isopropyl-amino)-[1,3,5]triazin-2-ol (14d) exhibited low nanomolar potency in the in vitro enzyme inhibition assay (IC(50) = 18 nM) and submicromolar inhibitory activity in a KDR-induced MAP kinase autophosphorylation assay in HUVEC cells (IC(50) = 280 nM), and also demonstrated good in vitro selectivity against a panel of growth factor receptor tyrosine kinases. Further, 14d showed antiangiogenic activity in an aortic ring explant assay by blocking endothelial outgrowths in rat aortas with an IC(50) of 1 microM.
Assuntos
Inibidores da Angiogênese/síntese química , Tiazóis/síntese química , Triazinas/síntese química , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/química , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Benzotiazóis , Capilares/efeitos dos fármacos , Capilares/fisiologia , Linhagem Celular , Técnicas de Química Combinatória , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Humanos , Técnicas de Cultura de Órgãos , Fosforilação , Ratos , Relação Estrutura-Atividade , Tiazóis/química , Tiazóis/farmacologia , Triazinas/química , Triazinas/farmacologia , Veias Umbilicais/citologiaRESUMO
Attenuation of fructose metabolism by the inhibition of ketohexokinase (KHK; fructokinase) should reduce body weight, free fatty acids, and triglycerides, thereby offering a novel approach to treat diabetes and obesity in response to modern diets. We have identified potent, selective inhibitors of human hepatic KHK within a series of pyrimidinopyrimidines (1). For example, 8, 38, and 47 exhibited KHK IC50 values of 12, 7, and 8 nM, respectively, and also showed potent cellular KHK inhibition (IC50 < 500 nM), which relates to their intrinsic potency vs KHK and their ability to penetrate cells. X-ray cocrystal structures of KHK complexes of 3, 8, and 47 revealed the important interactions within the enzyme's adenosine 5'-triphosphate (ATP)-binding pocket.
RESUMO
A series of 2'-aminoanilides have been identified which exhibit potent and selective inhibitory activity against the cFMS tyrosine kinase. Initial SAR studies within this series are described which examine aroyl and amino group substitutions, as well as the introduction of hydrophilic substituents on the benzene core. Compound 47 inhibits the isolated enzyme (IC(50)=0.027 microM) and blocks CSF-1-induced proliferation of bone marrow-derived macrophages (IC(50)=0.11 microM) and as such, serves as a lead candidate for further optimization studies.
Assuntos
Anilidas/síntese química , Anilidas/farmacologia , Anti-Inflamatórios/farmacologia , Piperidinas/química , Inibidores de Proteínas Quinases/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Anilidas/química , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Concentração Inibidora 50 , Macrófagos/efeitos dos fármacos , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-AtividadeRESUMO
The cFMS proto-oncogene encodes for the colony-stimulating factor-1 receptor, a receptor-tyrosine kinase responsible for the differentiation and maturation of certain macrophages. Upon binding its ligand colony-stimulating factor-1 cFMS autophosphorylates, dimerizes, and induces phosphorylation of downstream targets. We report the novel crystal structure of unphosphorylated cFMS in complex with two members of different classes of drug-like protein kinase inhibitors. cFMS exhibits a typical bi-lobal kinase fold, and its activation loop and DFG motif are found to be in the canonical inactive conformation. Both ATP competitive inhibitors are bound in the active site and demonstrate a binding mode similar to that of STI-571 bound to cABL. The DFG motif is prevented from switching into the catalytically competent conformation through interactions with the inhibitors. Activation of cFMS is also inhibited by the juxtamembrane domain, which interacts with residues of the active site and prevents formation of the activated kinase. Together the structures of cFMS provide further insight into the autoinhibition of receptor-tyrosine kinases via their respective juxtamembrane domains; additionally the binding mode of two novel classes of kinase inhibitors will guide the design of novel molecules targeting macrophage-related diseases.
Assuntos
Inibidores de Proteínas Quinases/química , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/química , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Receptor de Fator Estimulador de Colônias de Macrófagos/química , Amidas/química , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Humanos , Dados de Sequência Molecular , Proteínas Mutantes Quiméricas/antagonistas & inibidores , Proteínas Mutantes Quiméricas/química , Estrutura Terciária de Proteína/genética , Proto-Oncogene Mas , Quinolonas/química , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Receptor de Fator Estimulador de Colônias de Macrófagos/genética , Receptor de Fator Estimulador de Colônias de Macrófagos/metabolismo , Receptor TIE-2/química , Receptor TIE-2/genética , Receptores de Fatores de Crescimento de Fibroblastos/química , Receptores de Fatores de Crescimento de Fibroblastos/genéticaRESUMO
A parallel approach to designing crystallization constructs for the c-FMS kinase domain was implemented, resulting in proteins suitable for structural studies. Sequence alignment and limited proteolysis were used to identify and eliminate unstructured and surface-exposed domains. A small library of chimeras was prepared in which the kinase insert domain of FMS was replaced with the kinase insert domain of previously crystallized receptor-tyrosine kinases. Characterization of the newly generated FMS constructs by enzymology and thermoshift assays demonstrated similar activities and compound binding to the FMS full-length cytoplasmic domain. Two chimeras were evaluated for crystallization in the presence and absence of a variety of ligands resulting in crystal structures, and leading to a successful structure-based drug design project for this important inflammation target.
Assuntos
Engenharia de Proteínas , Receptores Proteína Tirosina Quinases/síntese química , Receptores Proteína Tirosina Quinases/genética , Receptor de Fator Estimulador de Colônias de Macrófagos/química , Receptor de Fator Estimulador de Colônias de Macrófagos/genética , Sequência de Aminoácidos , Animais , Células Cultivadas , Cristalização , Citoplasma/química , Citoplasma/genética , Humanos , Dados de Sequência Molecular , Proteínas Mutantes Quiméricas/síntese química , Proteínas Mutantes Quiméricas/genética , Inibidores de Proteínas Quinases/química , Estrutura Terciária de Proteína/genética , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Alinhamento de Sequência , SpodopteraRESUMO
A new class of Aurora-A inhibitors have been identified based on the 2-amino-pyrrolo[2,3-d]pyrimidine scaffold. Here, we describe the synthesis and SAR of this novel series. We report compounds which exhibit nanomolar activity in the Aurora-A biochemical assay and are able to inhibit tumor cell proliferation. This study culminates in compound 30, an inhibitor with potent activity against Aurora A (IC50=0.008 microM), anti-proliferative activity against several tumor cell lines and induces polyploidy in H460 cells.