RESUMO
The terminal dipeptide, D-Ala-D-Ala, of the peptidoglycan precursor UDPMurNAc-pentapetide is a crucial building block involved in peptidoglycan cross-linking. It is synthesized in the bacterial cytoplasm by the enzyme d-alanine:d-alanine ligase (Ddl). Structure-based virtual screening of the NCI diversity set of almost 2000 compounds was performed with a DdlB isoform from Escherichia coli using the computational tool AutoDock 4.0. The 130 best-ranked compounds from this screen were tested in an in vitro assay for their inhibition of E. coli DdlB. Three compounds were identified that inhibit the enzyme with K(i) values in micromolar range. Two of these also have promising antibacterial activities against Gram-positive and Gram-negative bacteria.
Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Oligopeptídeos/farmacologia , Peptídeo Sintases/antagonistas & inibidores , Domínio Catalítico , Simulação por Computador , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Ligação de Hidrogênio , Modelos Químicos , Modelos Moleculares , Estrutura Molecular , Oligopeptídeos/química , Peptídeo Sintases/química , Relação Estrutura-AtividadeAssuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Projetos de Pesquisa , Animais , Antibacterianos/farmacocinética , Bactérias/efeitos dos fármacos , Bactérias/enzimologia , Infecções Bacterianas/microbiologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Metionina tRNA Ligase/antagonistas & inibidores , SoftwareRESUMO
The defining property of an antibacterial agent is its ability to selectively interfere with bacterial growth and/or survival. Consequently, a considerable and crucial part of the preclinical evaluation of any novel antibacterial drug involves judging and characterising its effects on bacteria in vitro. These critical stages in drug development are sometimes made to appear somewhat trivial, sandwiched as they are between the highly demanding antibacterial discovery process and the formidable task of demonstrating safety and efficacy in vivo. However, careful biological evaluation in vitro is key to quantifying and understanding the basis of the antibacterial activity, providing preliminary indications and evaluations of therapeutic potential, assessing the likelihood for the development of bacterial resistance, guiding chemical refinement and assisting subsequent stages of the appraisal of any new antibacterial drug. This review covers concepts in, and strategies for, the in vitro microbiological and molecular evaluation of antibacterial drug candidates.