RESUMO
Anthrax is a highly lethal disease caused by the Gram-(+) bacteria Bacillus anthracis. Edema toxin (ET) is a major contributor to the pathogenesis of disease in humans exposed to B. anthracis. ET is a bipartite toxin composed of two proteins secreted by the vegetative bacteria, edema factor (EF) and protective antigen (PA). Our work towards identifying a small molecule inhibitor of anthrax edema factor is the subject of this letter. First we demonstrate that the small molecule probe 5'-Fluorosulfonylbenzoyl 5'-adenosine (FSBA) reacts irreversibly with EF and blocks enzymatic activity. We then show that the adenosine portion of FSBA can be replaced to provide more drug-like molecules which are up to 1000-fold more potent against EF relative to FSBA, display low cross reactivity when tested against a panel of kinases, and are nanomolar inhibitors of EF in a cell-based assay of cAMP production.
Assuntos
Antraz/tratamento farmacológico , Bacillus anthracis/efeitos dos fármacos , Toxinas Bacterianas/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Antígenos de Bactérias/farmacologia , Toxinas Bacterianas/farmacologia , AMP Cíclico/antagonistas & inibidores , AMP Cíclico/biossíntese , Relação Dose-Resposta a Droga , Humanos , Camundongos , Estrutura Molecular , Proteínas Quinases/metabolismo , Células RAW 264.7 , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-AtividadeRESUMO
A novel method for applying high-throughput docking to challenging metalloenzyme targets is described. The method utilizes information-based virtual transformation of library carboxylates to hydroxamic acids prior to docking, followed by compound acquisition, one-pot (two steps) chemical synthesis and in vitro screening. In two experiments targeting the botulinum neurotoxin serotype A metalloprotease light chain, hit rates of 32% and 18% were observed.
Assuntos
Toxinas Botulínicas Tipo A/antagonistas & inibidores , Inibidores de Proteases/química , Sítios de Ligação , Toxinas Botulínicas Tipo A/metabolismo , Ácidos Carboxílicos/química , Domínio Catalítico , Química Farmacêutica , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Ácidos Hidroxâmicos/química , Simulação de Acoplamento Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/metabolismo , Ligação Proteica , Sorotipagem , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Relação Estrutura-AtividadeRESUMO
Four core structures capable of providing sub-nanomolar inhibitors of anthrax lethal factor (LF) were evaluated by comparing the potential for toxicity, physicochemical properties, in vitro ADME profiles, and relative efficacy in a rat lethal toxin (LT) model of LF intoxication. Poor efficacy in the rat LT model exhibited by the phenoxyacetic acid series (3) correlated with low rat microsome and plasma stability. Specific molecular interactions contributing to the high affinity of inhibitors with a secondary amine in the C2-side chain were revealed by X-ray crystallography.
Assuntos
Acetatos/síntese química , Antraz/tratamento farmacológico , Antídotos/síntese química , Bacillus anthracis/efeitos dos fármacos , Toxinas Bacterianas/antagonistas & inibidores , Acetatos/farmacocinética , Acetatos/farmacologia , Animais , Antídotos/farmacocinética , Antídotos/farmacologia , Antígenos de Bactérias , Bacillus anthracis/fisiologia , Cristalografia por Raios X , Citocromo P-450 CYP2D6/metabolismo , Inibidores do Citocromo P-450 CYP2D6 , Microssomos Hepáticos/enzimologia , Modelos Moleculares , Coelhos , RatosRESUMO
New anthrax lethal factor inhibitors (LFIs) were designed based upon previously identified potent inhibitors 1a and 2. Combining the new core structures with modifications to the C2-side chain yielded analogs with improved efficacy in the rat lethal toxin model.
Assuntos
Antídotos/uso terapêutico , Antígenos de Bactérias/intoxicação , Toxinas Bacterianas/intoxicação , Animais , Estrutura Molecular , Intoxicação/tratamento farmacológico , RatosRESUMO
Sub-nanomolar small molecule inhibitors of anthrax lethal factor have been identified using SAR and Merck L915 (4) as a model compound. One of these compounds (16) provided 100% protection in a rat lethal toxin model of anthrax disease.