RESUMO
Structural genomics, the large-scale determination of protein structures, promises to provide a broad structural foundation for drug discovery. The tuberculosis (TB) Structural Genomics Consortium is devoted to encouraging, coordinating, and facilitating the determination of structures of proteins from Mycobacterium tuberculosis and hopes to determine 400 TB protein structures over 5 years. The Consortium has determined structures of 28 proteins from TB to date. These protein structures are already providing a basis for drug discovery efforts.
Assuntos
Aciltransferases , Antibacterianos/farmacologia , Antígenos de Bactérias , Proteínas de Bactérias/química , Desenho de Fármacos , Genômica , Mycobacterium tuberculosis/química , Mycobacterium tuberculosis/efeitos dos fármacos , Aldeído Liases/química , Sistema Enzimático do Citocromo P-450/química , Glutamato-Amônia Ligase/química , Metiltransferases/química , Mio-Inositol-1-Fosfato Sintase/química , Oxirredutases/química , Isomerases de Dissulfetos de Proteínas/químicaRESUMO
There is a dire need for novel therapeutics to treat the virulent malarial parasite, Plasmodium falciparum. Recently, the X-ray crystal structure of enoyl-acyl carrier protein reductase (ENR) in complex with triclosan has been determined and provides an opportunity for the rational design of novel inhibitors targeting the active site of ENR. Here, we report the discovery of several compounds by virtual screening and their experimental validation as high potency PfENR inhibitors.
Assuntos
Antimaláricos/farmacologia , Desenho de Fármacos , Enoil-(Proteína de Transporte de Acila) Redutase (NADH)/antagonistas & inibidores , Plasmodium falciparum/enzimologia , Animais , Antimaláricos/química , Sítios de Ligação , Células CACO-2 , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Humanos , Ligação de Hidrogênio , Cinética , Malária/tratamento farmacológico , Modelos Moleculares , Triclosan/química , Triclosan/farmacologiaRESUMO
Tuberculosis and malaria together result in an estimated 5 million deaths annually. The spread of multidrug resistance in the most pathogenic causative agents, Mycobacterium tuberculosis and Plasmodium falciparum, underscores the need to identify active compounds with novel inhibitory properties. Although genetically unrelated, both organisms use a type II fatty-acid synthase system. Enoyl acyl carrier protein reductase (ENR), a key type II enzyme, has been repeatedly validated as an effective antimicrobial target. Using high throughput inhibitor screens with a combinatorial library, we have identified two novel classes of compounds with activity against the M. tuberculosis and P. falciparum enzyme (referred to as InhA and PfENR, respectively). The crystal structure of InhA complexed with NAD+ and one of the inhibitors was determined to elucidate the mode of binding. Structural analysis of InhA with the broad spectrum antimicrobial triclosan revealed a unique stoichiometry where the enzyme contained either a single triclosan molecule, in a configuration typical of other bacterial ENR:triclosan structures, or harbored two triclosan molecules bound to the active site. Significantly, these compounds do not require activation and are effective against wild-type and drug-resistant strains of M. tuberculosis and P. falciparum. Moreover, they provide broader chemical diversity and elucidate key elements of inhibitor binding to InhA for subsequent chemical optimization.