RESUMO
Heat-shock protein 47 (HSP47) is a potential target for inhibitors that ameliorate fibrosis by reducing collagen assembly. In an effort to develop a structure-based drug-design system, it was not possible to replicate a previous literature result (PDB entry 4au4) for apo dog HSP47; instead, crystal forms were obtained in which pairs of dog HSP47 molecules interacted through a noncleavable C-terminal His-tag to build up tetramers, all of which had multiple molecules of HSP47 in the asymmetric unit and none of which diffracted as well as the literature precedent. To overcome these difficulties, a two-pronged approach was followed: (i) the His-tag was moved from the C-terminus to the N-terminus and was made cleavable, and (ii) Adnectin (derived from the tenth domain of human fibronectin type III) crystallization chaperones were developed. Both approaches provided well diffracting crystals, but the latter approach yielded crystal forms with only one or two HSP47 complexes per asymmetric unit, which made model building less onerous.
RESUMO
Starting from the dialkylaniline indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor lead 3 (IDO1 HeLa IC50 = 7.0 nM), an iterative process of synthesis and screening led to cyclized analog 21 (IDO1 HeLa IC50 = 3.6 nM) which maintained the high potency of 3 while addressing issues of lipophilicity, cytochrome P450 (CYP) inhibition, hERG (human potassium ion channel Kv11.1) inhibition, Pregnane X Receptor (PXR) transactivation, and oxidative metabolic stability. An x-ray crystal structure of a biaryl alkyl ether 11 bound to IDO1 was obtained. Consistent with our earlier results, compound 11 was shown to bind to the apo form of the enzyme.
Assuntos
Inibidores Enzimáticos , Éteres , Humanos , Relação Estrutura-Atividade , Inibidores Enzimáticos/química , Células HeLa , Indolamina-Pirrol 2,3,-DioxigenaseRESUMO
Proteolysis-targeting chimeras (PROTACs) represent a new direction in small-molecule therapeutics whereby a heterobifunctional linker to a protein of interest (POI) induces its ubiquitination-based proteolysis by recruiting an E3 ligase. Here, we show that charge reduction, native mass spectrometry, and gas-phase activation methods combine for an in-depth analysis of a PROTAC-linked ternary complex. Electron capture dissociation (ECD) of the intact POI-PROTAC-VCB complex (a trimeric subunit of an E3 ubiquitin ligase) promotes POI dissociation. Collision-induced dissociation (CID) causes elimination of the nonperipheral PROTAC, producing an intact VCB-POI complex not seen in solution but consistent with PROTAC-induced protein-protein interactions. In addition, we used ion mobility spectrometry (IMS) and collisional activation to identify the source of this unexpected dissociation. Together, the evidence shows that this integrated approach can be used to screen for ternary complex formation and PROTAC-protein contacts and may report on PROTAC-induced protein-protein interactions, a characteristic correlated with PROTAC selectivity and efficacy.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Gases/química , Espectrometria de Mobilidade Iônica/métodos , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Ciclo Celular/química , Mapas de Interação de Proteínas , Proteólise , Fatores de Transcrição/química , Ubiquitina-Proteína Ligases/químicaRESUMO
Hematopoietic progenitor kinase 1 (HPK1) is an intracellular kinase that plays an important role in modulating tumor immune response and thus is an attractive target for drug discovery. Crystallization of the wild-type HPK1 kinase domain has been hampered by poor expression in recombinant systems and poor solubility. In this study, yeast surface display was applied to a library of HPK1 kinase-domain variants in order to select variants with an improved expression level and solubility. The HPK1 variant with the most improved properties contained two mutations, crystallized readily in complex with several small-molecule inhibitors and provided valuable insight to guide structure-based drug design. This work exemplifies the benefit of yeast surface display towards engineering crystallizable proteins and thus enabling structure-based drug discovery.
Assuntos
Engenharia de Proteínas/métodos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Técnicas de Visualização da Superfície Celular , Cristalização , Cristalografia por Raios X , Humanos , Modelos Moleculares , Mutagênese , Mutação , Domínios Proteicos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genéticaRESUMO
IRAK4 is an attractive therapeutic target for the treatment of inflammatory conditions. Structure guided optimization of a nicotinamide series of inhibitors has been expanded to explore the IRAK4 front pocket. This has resulted in the identification of compounds such as 12 with improved potency and selectivity. Additionally 12 demonstrated activity in a pharmacokinetics/pharmacodynamics (PK/PD) model. Further optimization efforts led to the identification of the highly kinome selective 21, which demonstrated a robust PD effect and efficacy in a TLR7 driven model of murine psoriasis.
RESUMO
For cancer cells to survive and proliferate, they must escape normal immune destruction. One mechanism by which this is accomplished is through immune suppression effected by up-regulation of indoleamine 2,3-dioxygenase (IDO1), a heme enzyme that catalyzes the oxidation of tryptophan to N-formylkynurenine. On deformylation, kynurenine and downstream metabolites suppress T cell function. The importance of this immunosuppressive mechanism has spurred intense interest in the development of clinical IDO1 inhibitors. Herein, we describe the mechanism by which a class of compounds effectively and specifically inhibits IDO1 by targeting its apo-form. We show that the in vitro kinetics of inhibition coincide with an unusually high rate of intrinsic enzyme-heme dissociation, especially in the ferric form. X-ray crystal structures of the inhibitor-enzyme complexes show that heme is displaced from the enzyme and blocked from rebinding by these compounds. The results reveal that apo-IDO1 serves as a unique target for inhibition and that heme lability plays an important role in posttranslational regulation.
Assuntos
Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indolamina-Pirrol 2,3,-Dioxigenase/química , Apoproteínas/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Células HeLa , Heme/metabolismo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Concentração Inibidora 50 , Mioglobina/químicaRESUMO
The cytokine TGF-ß modulates a number of cellular activities and plays a critical role in development, hemostasis and physiology, as well as in diseases including cancer and fibrosis. TGF-ß signals through two transmembrane serine/threonine kinase receptors: TGFßR1 and TGFßR2. Multiple structures of the TGFßR1 kinase domain are known, but the structure of TGFßR2 remains unreported. Wild-type TGFßR2 kinase domain was refractory to crystallization, leading to the design of two mutated constructs: firstly, a TGFßR1 chimeric protein with seven ATP-site residues mutated to their counterparts in TGFßR2, and secondly, a reduction of surface entropy through mutation of six charged residues on the surface of the TGFßR2 kinase domain to alanines. These yielded apo and inhibitor-bound crystals that diffracted to high resolution (<2â Å). Comparison of these structures with those of TGFßR1 reveal shared ligand contacts as well as differences in the ATP-binding sites, suggesting strategies for the design of pan and selective TGFßR inhibitors.
Assuntos
Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/química , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Receptores de Fatores de Crescimento Transformadores beta/química , Trifosfato de Adenosina/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Humanos , Ligantes , Modelos Moleculares , Ligação Proteica , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/metabolismoRESUMO
Microtubule-associated protein/microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine kinase involved in the phosphorylation of MAP proteins that regulate microtubule dynamics. Abnormal activity of MARK4 has been proposed to contribute to neurofibrillary tangle formation in Alzheimer's disease. The crystal structure of the catalytic and ubiquitin-associated domains of MARK4 with a potent pyrazolopyrimidine inhibitor has been determined to 2.8â Å resolution with an Rwork of 22.8%. The overall structure of MARK4 is similar to those of the other known MARK isoforms. The inhibitor is located in the ATP-binding site, with the pyrazolopyrimidine group interacting with the inter-lobe hinge region while the aminocyclohexane moiety interacts with the catalytic loop and the DFG motif, forcing the activation loop out of the ATP-binding pocket.
Assuntos
Cristalização/métodos , Cristalografia por Raios X/métodos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Pirazóis/química , Pirazóis/metabolismo , Pirimidinas/química , Pirimidinas/metabolismo , Sequência de Aminoácidos , Humanos , Dados de Sequência Molecular , Conformação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismoRESUMO
Efforts to identify a potent, reversible, nonsteroidal CYP17A1 lyase inhibitor with good selectivity over CYP17A1 hydroxylase and CYPs 11B1 and 21A2 for the treatment of castration-resistant prostate cancer (CRPC) culminated in the discovery of BMS-351 (compound 18), a pyridyl biaryl benzimidazole with an excellent in vivo profile. Biological evaluation of BMS-351 at a dose of 1.5 mg in castrated cynomolgus monkeys revealed a remarkable reduction in testosterone levels with minimal glucocorticoid and mineralcorticoid perturbation. Based on a favorable profile, BMS-351 was selected as a candidate for further preclinical evaluation.
RESUMO
A significant challenge in the molecular interaction field is to accurately determine the stoichiometry and stepwise binding affinity constants for macromolecules having >1 binding site. The mission of the Molecular Interactions Research Group (MIRG) of the Association of Biomolecular Resource Facilities (ABRF) is to show how biophysical technologies are used to quantitatively characterize molecular interactions, and to educate the ABRF members and scientific community on the utility and limitations of core technologies [such as biosensor, microcalorimetry, or analytic ultracentrifugation (AUC)]. In the present work, the MIRG has developed a robust model protein interaction pair consisting of a bivalent variant of the Bacillus amyloliquefaciens extracellular RNase barnase and a variant of its natural monovalent intracellular inhibitor protein barstar. It is demonstrated that this system can serve as a benchmarking tool for the quantitative analysis of 2-site protein-protein interactions. The protein interaction pair enables determination of precise binding constants for the barstar protein binding to 2 distinct sites on the bivalent barnase binding partner (termed binase), where the 2 binding sites were engineered to possess affinities that differed by 2 orders of magnitude. Multiple MIRG laboratories characterized the interaction using isothermal titration calorimetry (ITC), AUC, and surface plasmon resonance (SPR) methods to evaluate the feasibility of the system as a benchmarking model. Although general agreement was seen for the binding constants measured using solution-based ITC and AUC approaches, weaker affinity was seen for surface-based method SPR, with protein immobilization likely affecting affinity. An analysis of the results from multiple MIRG laboratories suggests that the bivalent barnase-barstar system is a suitable model for benchmarking new approaches for the quantitative characterization of complex biomolecular interactions.
Assuntos
Mapeamento de Interação de Proteínas/normas , Sequência de Aminoácidos , Área Sob a Curva , Proteínas de Bactérias/química , Endorribonucleases/química , Enzimas Imobilizadas/química , Estudos de Avaliação como Assunto , Dados de Sequência Molecular , Ligação Proteica , Mapeamento de Interação de Proteínas/métodos , Padrões de Referência , Ressonância de Plasmônio de Superfície , TermodinâmicaRESUMO
Programmed death-1 (PD-1) protein is a co-inhibitory receptor which negatively regulates immune cell activation and permits tumors to evade normal immune defense. Anti-PD-1 antibodies have been shown to restore immune cell activation and effector function-an exciting breakthrough in cancer immunotherapy. Recent reports have documented a soluble form of PD-1 (sPD-1) in the circulation of normal and disease state individuals. A clinical assay to quantify sPD-1 would contribute to the understanding of sPD-1-function and facilitate the development of anti-PD-1 drugs. Here, we report the development and validation of a sPD-1 protein assay. The assay validation followed the framework for full validation of a biotherapeutic pharmacokinetic assay. A purified recombinant human PD-1 protein was characterized extensively and was identified as the assay reference material which mimics the endogenous analyte in structure and function. The lower limit of quantitation (LLOQ) was determined to be 100 pg/mL, with a dynamic range spanning three logs to 10,000 pg/mL. The intra- and inter-assay imprecision were ≤15%, and the assay bias (percent deviation) was ≤10%. Potential matrix effects were investigated in sera from both normal healthy volunteers and selected cancer patients. Bulk-prepared frozen standards and pre-coated Streptavidin plates were used in the assay to ensure consistency in assay performance over time. This assay appears to specifically measure total sPD-1 protein since the human anti-PD-1 antibody, nivolumab, and the endogenous ligands of PD-1 protein, PDL-1 and PDL-2, do not interfere with the assay.
Assuntos
Bioensaio/métodos , Receptor de Morte Celular Programada 1/análise , Proteínas Recombinantes/análise , Anticorpos Monoclonais/administração & dosagem , Estudos de Casos e Controles , Células HEK293 , Humanos , Limite de Detecção , Neoplasias/sangue , NivolumabeRESUMO
Glycogen synthase kinase-3 (GSK-3) has been proposed to play a crucial role in the pathogenesis of many diseases including cancer, stroke, bipolar disorders, diabetes and neurodegenerative diseases. GSK-3 inhibition has been a major area of pharmaceutical interest over the last two decades. A plethora of reports appeared recently on selective inhibitors and their co-crystal structures in GSK-3ß. We identified several series of promising new GSK-3ß inhibitors from a coherent design around a pyrrolopyridinone core structure. A systematic exploration of the chemical space around the central spacer led to potent single digit and sub-nanomolar GSK-3ß inhibitors. When dosed orally in a transgenic mouse model of Alzheimer's disease (AD), an exemplary compound showed significant lowering of Tau phosphorylation at one of the GSK-3 phosphorylating sites, Ser396. X-ray crystallography greatly aided in validating the binding hypotheses.
Assuntos
Aminopiridinas/farmacologia , Descoberta de Drogas , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Piridonas/química , Pirróis/química , Aminopiridinas/administração & dosagem , Aminopiridinas/química , Animais , Cristalografia por Raios X , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/química , Relação Estrutura-AtividadeRESUMO
A multidisciplinary, fragment-based screening approach involving protein ensemble docking and biochemical and NMR assays is described. This approach led to the discovery of several structurally diverse, neutral surrogates for cationic factor VIIa P1 groups, which are generally associated with poor pharmacokinetic (PK) properties. Among the novel factor VIIa inhibitory fragments identified were aryl halides, lactams, and heterocycles. Crystallographic structures for several bound fragments were obtained, leading to the successful design of a potent factor VIIa inhibitor with a neutral lactam P1 and improved permeability.
Assuntos
Desenho de Fármacos , Fator VIIa/antagonistas & inibidores , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Cristalografia por Raios X , Fator VIIa/metabolismo , Halogênios/química , Halogênios/farmacologia , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Humanos , Lactamas/metabolismo , Lactamas/farmacologia , Modelos Moleculares , Simulação de Acoplamento MolecularRESUMO
A novel series of p38 MAP kinase inhibitors with high selectivity for the p38α isoform over the other family members including the highly homologous p38ß isoform has been identified. X-ray co-crystallographic studies have revealed an unprecedented kinase binding mode in p38α for representative analogs, 5c and 9d, in which a Leu108/Met109 peptide flip occurs within the p38α hinge region. Based on these findings, a general strategy for the rational design of additional promising p38α isoform selective inhibitors by targeting this novel binding mode is proposed.
Assuntos
Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Sítios de Ligação , Cristalografia por Raios X , Humanos , Ligação de Hidrogênio , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Simulação de Dinâmica Molecular , Ligação Proteica , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/metabolismo , Estrutura Terciária de Proteína , Relação Estrutura-AtividadeRESUMO
Pyrrolo[2,1-f][1,2,4]triazine based inhibitors of p38α have been prepared exploring functional group modifications at the C6 position. Incorporation of aryl and heteroaryl ketones at this position led to potent inhibitors with efficacy in in vivo models of acute and chronic inflammation.
Assuntos
Anti-Inflamatórios/química , Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Pirróis/química , Triazinas/química , Administração Oral , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Artrite/tratamento farmacológico , Sítios de Ligação , Cristalografia por Raios X , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Camundongos , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Estrutura Terciária de Proteína , Ratos , Relação Estrutura-Atividade , Triazinas/farmacologia , Triazinas/uso terapêuticoRESUMO
The synthesis and structure-activity relationships (SAR) of p38α MAP kinase inhibitors based on a 5-amino-pyrazole scaffold are described. These studies led to the identification of compound 2j as a potent and selective inhibitor of p38α MAP kinase with excellent cellular potency toward the inhibition of TNFα production. Compound 2j was highly efficacious in vivo in inhibiting TNFα production in an acute murine model of TNFα production. X-ray co-crystallography of a 5-amino-pyrazole analog 2f bound to unphosphorylated p38α is also disclosed.
Assuntos
Proteína Quinase 14 Ativada por Mitógeno/química , Inibidores de Proteínas Quinases/síntese química , Pirazóis/farmacologia , Animais , Cristalografia por Raios X , Camundongos , Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Ligação Proteica , Conformação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The discovery and characterization of 7k (BMS-582949), a highly selective p38α MAP kinase inhibitor that is currently in phase II clinical trials for the treatment of rheumatoid arthritis, is described. A key to the discovery was the rational substitution of N-cyclopropyl for N-methoxy in 1a, a previously reported clinical candidate p38α inhibitor. Unlike alkyl and other cycloalkyls, the sp(2) character of the cyclopropyl group can confer improved H-bonding characteristics to the directly substituted amide NH. Inhibitor 7k is slightly less active than 1a in the p38α enzymatic assay but displays a superior pharmacokinetic profile and, as such, was more effective in both the acute murine model of inflammation and pseudoestablished rat AA model. The binding mode of 7k with p38α was confirmed by X-ray crystallographic analysis.
Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Pirróis/síntese química , Triazinas/síntese química , Animais , Anti-Inflamatórios não Esteroides/farmacocinética , Anti-Inflamatórios não Esteroides/farmacologia , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Disponibilidade Biológica , Células CACO-2 , Cristalografia por Raios X , Feminino , Humanos , Ligação de Hidrogênio , Técnicas In Vitro , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Proteína Quinase 14 Ativada por Mitógeno/química , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Pirróis/farmacocinética , Pirróis/farmacologia , Ratos , Ratos Endogâmicos Lew , Ratos Sprague-Dawley , Estereoisomerismo , Relação Estrutura-Atividade , Triazinas/farmacocinética , Triazinas/farmacologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The design, synthesis, and structure-activity relationships (SAR) of a series of 2-aminothiazol-5-yl-pyrimidines as novel p38α MAP kinase inhibitors are described. These efforts led to the identification of 41 as a potent p38α inhibitor that utilizes a unique nitrogen-sulfur intramolecular nonbonding interaction to stabilize the conformation required for binding to the p38α active site. X-ray crystallographic studies that confirm the proposed binding mode of this class of inhibitors in p38 α and provide evidence for the proposed intramolecular nitrogen-sulfur interaction are discussed.
Assuntos
Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Nitrogênio/química , Inibidores de Proteínas Quinases/síntese química , Pirimidinas/química , Enxofre/química , Tiazóis/química , Sítios de Ligação , Cristalografia por Raios X , Desenho de Fármacos , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Estrutura Terciária de Proteína , Pirimidinas/síntese química , Pirimidinas/farmacologia , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/farmacologiaRESUMO
Eg5 is a kinesin whose inhibition leads to cycle arrest during mitosis, making it a potential therapeutic target in cancers. Circular dichroism and isothermal titration calorimetry of our pyrrolotriazine-4-one series of inhibitors with Eg5 motor domain revealed enhanced binding in the presence of adenosine 5'-diphosphate (ADP). Using this information, we studied the interaction of this series with ADP-Eg5 complexes using a thermal shift assay. We measured up to a 7 degrees C increase in the thermal melting (T(m)) of Eg5 for an inhibitor that produced IC(50) values of 60 and 130 nM in microtubule-dependent adenosine triphosphatase (ATPase) and cell-based cytotoxicity assays, respectively. In general, the inhibitor potency of the pyrrolotriazine-4-one series in in vitro biological assays correlated with the magnitude of the thermal stability enhancement of ADP-Eg5. The thermal shift assay also confirmed direct binding of Eg5 inhibitors identified in a high-throughput screen and demonstrated that the thermal shift assay is applicable to a range of chemotypes and can be useful in evaluating both potent (nM) and relatively weakly binding (microM) leads. Overall, the thermal shift assay was found to be an excellent biophysical method for evaluating direct binding of a large number of compounds to Eg5, and it complemented the catalytic assay screens by providing an alternative determination of inhibitor potency.
Assuntos
Bioquímica/métodos , Cinesinas/química , Pirróis/análise , Pirróis/química , Triazinas/análise , Triazinas/química , Difosfato de Adenosina/metabolismo , Fenômenos Biofísicos , Calorimetria , Linhagem Celular Tumoral , Dicroísmo Circular , Humanos , Cinesinas/metabolismo , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Ligação Proteica , Desnaturação Proteica , Dobramento de Proteína , Estrutura Terciária de Proteína , TemperaturaRESUMO
Fragment-like inhibitors of mitogen-activated protein kinase-activated protein kinase 2 (MK2) include 5-hydroxyisoquinoline (IC50 approximately 85 microM). Modeling studies identified four possible binding modes for this compound. Two-dimensional (1)H-(1)H NOESY data obtained with selectively protonated samples of MK2 in complex with 5-hydroxyisoquinoline demonstrated that two of the four predicted binding modes are well populated. A second small isoquinoline was subsequently shown to bind in a single mode. NMR and modeling studies using this general approach are expected to facilitate "scaffold hopping" and structure-guided elaborations of fragment-like kinase inhibitor cores.