RESUMO
The movement of core-lipopolysaccharide across the inner membrane of Gram-negative bacteria is catalysed by an essential ATP-binding cassette transporter, MsbA. Recent structures of MsbA and related transporters have provided insights into the molecular basis of active lipid transport; however, structural information about their pharmacological modulation remains limited. Here we report the 2.9 Å resolution structure of MsbA in complex with G907, a selective small-molecule antagonist with bactericidal activity, revealing an unprecedented mechanism of ABC transporter inhibition. G907 traps MsbA in an inward-facing, lipopolysaccharide-bound conformation by wedging into an architecturally conserved transmembrane pocket. A second allosteric mechanism of antagonism occurs through structural and functional uncoupling of the nucleotide-binding domains. This study establishes a framework for the selective modulation of ABC transporters and provides rational avenues for the design of new antibiotics and other therapeutics targeting this protein family.
Assuntos
Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/química , Antibacterianos/química , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Quinolinas/química , Quinolinas/farmacologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Regulação Alostérica/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Sítios de Ligação/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Escherichia coli/química , Hidrocarbonetos/química , Hidrocarbonetos/metabolismo , Lipopolissacarídeos/química , Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologia , Modelos Moleculares , Domínios Proteicos/efeitos dos fármacosRESUMO
Structure-based design was utilized to optimize 6,6-diaryl substituted dihydropyrone and hydroxylactam to obtain inhibitors of lactate dehydrogenase (LDH) with low nanomolar biochemical and single-digit micromolar cellular potencies. Surprisingly the replacement of a phenyl with a pyridyl moiety in the chemical structure revealed a new binding mode for the inhibitors with subtle conformational change of the LDHA active site. This led to the identification of a potent, cell-active hydroxylactam inhibitor exhibiting an in vivo pharmacokinetic profile suitable for mouse tumor xenograft study.
Assuntos
Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Lactamas/farmacologia , Animais , Linhagem Celular , Cães , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Humanos , L-Lactato Desidrogenase/metabolismo , Lactamas/química , Camundongos , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Herein we present an investigation into the scope and mechanism for the synthesis of cyclopentyl and heterocyclic fused pyridones from the corresponding enyne amides. In the presence of a secondary amine, cyclization proceeds smoothly to form 5,6-bicyclic pyridones in 12-90% yield. The cyclization fails with enyne amides of six-membered and larger ring systems. The ring closure reaction is catalytic in nature with respect to the secondary amine and proceeds via sequential 1,6-addition of the amine, 6-exo-trig ring closure of the iminium intermediate, and subsequent elimination of the secondary amine. Computations show reduced conjugation between the enyne and amide for six-membered and larger systems, thereby providing an explanation for the inability of such enyne amides to form fused pyridones.
Assuntos
Amidas , Piridonas , Catálise , Ciclização , Estrutura MolecularRESUMO
Phenolic groups are responsible for the high clearance and low oral bioavailability of the estrogen receptor alpha (ERα) clinical candidate GDC-0927. An exhaustive search for a backup molecule with improved pharmacokinetic (PK) properties identified several metabolically stable analogs, although in general at the expense of the desired potency and degradation efficiency. C-8 hydroxychromene 30 is the first example of a phenol-containing chromene that not only maintained excellent potency but also exhibited 10-fold higher oral exposure in rats. The improved in vivo clearance in rat was hypothesized to be the result of C-8 hydroxy group being sterically protected from glucuronide conjugation. The excellent potency underscores the possibility of replacing the presumed indispensable phenolic group at C-6 or C-7 of the chromene core. Co-crystal structures were obtained to highlight the change in key interactions and rationalize the retained potency.
Assuntos
Azetidinas/farmacologia , Receptor alfa de Estrogênio/metabolismo , Flavonoides/farmacologia , Administração Oral , Animais , Azetidinas/administração & dosagem , Azetidinas/metabolismo , Azetidinas/farmacocinética , Cristalografia por Raios X , Descoberta de Drogas , Estabilidade de Medicamentos , Flavonoides/administração & dosagem , Flavonoides/metabolismo , Flavonoides/farmacocinética , Humanos , Células MCF-7 , Microssomos Hepáticos/metabolismo , Ratos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Features from a high throughput screening (HTS) hit and a previously reported scaffold were combined to generate 1,7-naphthyridones as novel KDM5 enzyme inhibitors with nanomolar potencies. These molecules exhibited high selectivity over the related KDM4C and KDM2B isoforms. An X-ray co-crystal structure of a representative molecule bound to KDM5A showed that these inhibitors are competitive with the co-substrate (2-oxoglutarate or 2-OG).
Assuntos
Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Naftiridinas/farmacologia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Repressoras/antagonistas & inibidores , Proteína 2 de Ligação ao Retinoblastoma/antagonistas & inibidores , Animais , Cristalografia por Raios X , Cães , Desenho de Fármacos , Humanos , Células Madin Darby de Rim Canino , Naftiridinas/química , Relação Estrutura-AtividadeRESUMO
The dramatic increase in the prevalence of multi-drug resistant Gram-negative bacterial infections and the simultaneous lack of new classes of antibiotics is projected to result in approximately 10 million deaths per year by 2050. We report on efforts to target the Gram-negative ATP-binding cassette (ABC) transporter MsbA, an essential inner membrane protein that transports lipopolysaccharide from the inner leaflet to the periplasmic face of the inner membrane. We demonstrate the improvement of a high throughput screening hit into compounds with on-target single digit micromolar (µM) minimum inhibitory concentrations against wild-type uropathogenic Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae. A 2.98 Å resolution X-ray crystal structure of MsbA complexed with an inhibitor revealed a novel mechanism for inhibition of an ABC transporter. The identification of a fully encapsulated membrane binding site in Gram-negative bacteria led to unique physicochemical property requirements for wild-type activity.
Assuntos
Escherichia coli , Lipopolissacarídeos , Transportadores de Cassetes de Ligação de ATP , Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Klebsiella pneumoniae/metabolismo , Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologiaRESUMO
A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our efforts at further optimization of this series, culminating in 2 with submicromolar potency in a HWB assay and efficacy in a CIA mouse model.
Assuntos
Quinase I-kappa B/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Quinolinas/química , Semicarbazidas/química , Tioureia/análogos & derivados , Animais , Cães , Feminino , Hepatócitos/metabolismo , Ensaios de Triagem em Larga Escala , Humanos , Quinase I-kappa B/metabolismo , Macaca mulatta , Masculino , Camundongos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Quinolinas/síntese química , Quinolinas/farmacocinética , Ratos , Semicarbazidas/síntese química , Semicarbazidas/farmacocinética , Relação Estrutura-Atividade , Tioureia/síntese química , Tioureia/química , Tioureia/farmacocinéticaRESUMO
A novel series of (E)-1-((2-(1-methyl-1H-imidazol-5-yl) quinolin-4-yl) methylene) thiosemicarbazides was discovered as potent inhibitors of IKKß. In this Letter we document our early efforts at optimization of the quinoline core, the imidazole and the semithiocarbazone moiety. Most potency gains came from substitution around the 6- and 7-positions of the quinoline ring. Replacement of the semithiocarbazone with a semicarbazone decreased potency but led to some measurable exposure.
Assuntos
Quinase I-kappa B/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Semicarbazidas/química , Animais , Cães , Feminino , Ensaios de Triagem em Larga Escala , Quinase I-kappa B/metabolismo , Masculino , Microssomos/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Quinolinas/química , Ratos , Semicarbazidas/síntese química , Semicarbazidas/farmacocinética , Relação Estrutura-AtividadeRESUMO
Breast cancer remains a leading cause of cancer death in women, representing a significant unmet medical need. Here, we disclose our discovery efforts culminating in a clinical candidate, 35 (GDC-9545 or giredestrant). 35 is an efficient and potent selective estrogen receptor degrader (SERD) and a full antagonist, which translates into better antiproliferation activity than known SERDs (1, 6, 7, and 9) across multiple cell lines. Fine-tuning the physiochemical properties enabled once daily oral dosing of 35 in preclinical species and humans. 35 exhibits low drug-drug interaction liability and demonstrates excellent in vitro and in vivo safety profiles. At low doses, 35 induces tumor regressions either as a single agent or in combination with a CDK4/6 inhibitor in an ESR1Y537S mutant PDX or a wild-type ERα tumor model. Currently, 35 is being evaluated in Phase III clinical trials.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Carbolinas/uso terapêutico , Antagonistas do Receptor de Estrogênio/uso terapêutico , Receptor alfa de Estrogênio/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Carbolinas/química , Carbolinas/farmacocinética , Cães , Antagonistas do Receptor de Estrogênio/química , Antagonistas do Receptor de Estrogênio/farmacocinética , Feminino , Humanos , Células MCF-7 , Macaca fascicularis , Camundongos , Estrutura Molecular , Ratos , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A novel class of highly selective inhibitors of p38 MAP kinase was discovered from high throughput screening. The synthesis and optimization of a series of 5-amino-N-phenyl-1H-pyrazol-4-yl-3-phenylmethanones is described. An X-ray crystal structure of this series bound in the ATP binding pocket of unphosphorylated p38alpha established the presence of a unique hydrogen bond between the exocyclic amine of the inhibitor and threonine 106 which likely contributes to the selectivity for p38. The crystallographic information was used to optimize the potency and physicochemical properties of the series. The incorporation of the 2,3-dihydroxypropoxy moiety on the pyrazole scaffold resulted in a compound with excellent drug-like properties including high oral bioavailability. These efforts identified 63 (RO3201195) as an orally bioavailable and highly selective inhibitor of p38 which was selected for advancement into Phase I clinical trials.
Assuntos
Anti-Inflamatórios/síntese química , Pirazóis/síntese química , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Trifosfato de Adenosina/química , Administração Oral , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Artrite Experimental/tratamento farmacológico , Sítios de Ligação , Disponibilidade Biológica , Linhagem Celular , Cristalografia por Raios X , Cães , Feminino , Haplorrinos , Humanos , Interleucina-1/antagonistas & inibidores , Interleucina-1/biossíntese , Interleucina-6/antagonistas & inibidores , Interleucina-6/biossíntese , Modelos Moleculares , Pirazóis/química , Pirazóis/farmacologia , Ratos , Ratos Endogâmicos Lew , Estereoisomerismo , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/químicaRESUMO
A series of trisubstituted hydroxylactams was identified as potent enzymatic and cellular inhibitors of human lactate dehydrogenase A. Utilizing structure-based design and physical property optimization, multiple inhibitors were discovered with <10 µM lactate IC50 in a MiaPaca2 cell line. Optimization of the series led to 29, a potent cell active molecule (MiaPaca2 IC50 = 0.67 µM) that also possessed good exposure when dosed orally to mice.
RESUMO
In the past few years, there have been many advances in the efforts to cure patients with hepatitis C virus (HCV). The ultimate goal of these efforts is to develop a combination therapy consisting of only direct-antiviral agents (DAAs). In this paper, we discuss our efforts that led to the identification of a bicyclic template with potent activity against the NS5B polymerase, a critical enzyme on the life cycle of HCV. In continuation of our exploration to improve the stilbene series, the 3,5,6,8-tetrasubstituted quinoline core was identified as replacement of the stilbene moiety. 6-Methoxy-2(1H)-pyridone was identified among several heterocyclic headgroups to have the best potency. Solubility of the template was improved by replacing a planar aryl linker with a saturated pyrrolidine. Profiling of the most promising compounds led to the identification of quinoline 41 (RG7109), which was selected for advancement to clinical development.
Assuntos
Antivirais/farmacologia , Inibidores Enzimáticos/farmacologia , Hepacivirus/efeitos dos fármacos , Quinolinas/farmacologia , Sulfonamidas/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/química , Antivirais/farmacocinética , Cães , Descoberta de Drogas , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Hepacivirus/enzimologia , Humanos , Modelos Moleculares , Quinolinas/química , Quinolinas/farmacocinética , Ratos , Sulfonamidas/química , Sulfonamidas/farmacocinéticaRESUMO
The use of fragments with low binding affinity for their targets as starting points has received much attention recently. Screening of fragment libraries has been the most common method to find attractive starting points. Herein, we describe a unique, alternative approach to generating fragment leads. A binding model was developed and a set of guidelines were then selected to use this model to design fragments, enabling our discovery of a novel fragment with high LE.