RESUMO
ZipA is a membrane anchored protein in Escherichia coli that interacts with FtsZ, a homolog of eukaryotic tubulins, forming a septal ring structure that mediates bacterial cell division. Thus, the ZipA/FtsZ protein-protein interaction is a potential target for an antibacterial agent. We report here an NMR-based fragment screening approach which identified several hits that bind to the C-terminal region of ZipA. The screen was performed by 1H-15N HSQC experiments on a library of 825 fragments that are small, lead-like, and highly soluble. Seven hits were identified, and the binding mode of the best one was revealed in the X-ray crystal structure. Similar to the ZipA/FtsZ contacts, the driving force in the binding of the small molecule ligands to ZipA is achieved through hydrophobic interactions. Analogs of this hit were also evaluated by NMR and X-ray crystal structures of these analogs with ZipA were obtained, providing structural information to help guide the medicinal chemistry efforts.
Assuntos
Antibacterianos/síntese química , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Ciclo Celular/antagonistas & inibidores , Avaliação Pré-Clínica de Medicamentos/métodos , Proteínas de Escherichia coli/antagonistas & inibidores , Espectroscopia de Ressonância Magnética , Complexos Multiproteicos/antagonistas & inibidores , Antibacterianos/farmacologia , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cristalografia por Raios X , Desenho de Fármacos , Proteínas de Escherichia coli/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
The ZipA-FtsZ protein-protein interaction is a potential target for antibacterial therapy. The design and parallel synthesis of a combinatorial library of small molecules, which target the FtsZ binding area on ZipA are described. Compounds were demonstrated to bind to the FtsZ binding domain of ZipA by HSQC NMR and to inhibit cell division in a cell elongation assay.
Assuntos
Antibacterianos/síntese química , Proteínas de Transporte/química , Proteínas de Ciclo Celular/química , Proteínas de Escherichia coli/química , Indóis/síntese química , Piperidinas/síntese química , Antibacterianos/farmacologia , Divisão Celular/efeitos dos fármacos , Técnicas de Química Combinatória , Escherichia coli/citologia , Escherichia coli/efeitos dos fármacos , Indóis/farmacologia , Concentração Inibidora 50 , Piperidinas/farmacologia , Ligação Proteica/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
The binding of FtsZ to ZipA is a potential target for antibacterial therapy. Based on a small molecule inhibitor of the ZipA-FtsZ interaction, a parallel synthesis of small molecules was initiated which targeted a key region of ZipA involved in FtsZ binding. The X-ray crystal structure of one of these molecules complexed with ZipA was solved. The structure revealed an unexpected binding mode, facilitated by desolvation of a loosely bound surface water.
Assuntos
Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Desenho de Fármacos , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/metabolismo , Indóis/síntese química , Quinazolinas/síntese química , Sequência de Aminoácidos , Indóis/química , Indóis/metabolismo , Dados de Sequência Molecular , Ligação Proteica/fisiologia , Quinazolinas/química , Quinazolinas/metabolismoRESUMO
D-optimal design and Projection to Latent Structures (PLS) analysis were used to optimize screening hit 5 (B. subtilis AcpS IC(50): 15 microM, B. subtilis MIC: >200 microM) into a series of 4H-oxazol-5-one, small molecule, antibacterial, AcpS inhibitors. Specifically, 15, 16 and 18 show microM or sub-microM AcpS inhibition (IC(50)s: 15: 1.1 microM, 16: 1.5 microM, 18: 0.27 microM) and moderate antibacterial activity (MICs: 12.5-50 microM) against B. subtilis, E. faecalis ATCC, E. faecalis VRE and S. pneumo+.