RESUMO
Recent studies have shown that the DNA gyrase inhibitor, novobiocin, binds to a previously unrecognized ATP-binding site located at the C-terminus of Hsp90 and induces degradation of Hsp90-dependent client proteins at approximately 700 microM. As a result of these studies, several analogues of the coumarin family of antibiotics have been reported and shown to exhibit increased Hsp90 inhibitory activity; however, the monomeric species lacked the ability to manifest anti-proliferative activity against cancer cell lines at concentrations tested. In an effort to develop more efficacious compounds that produce growth inhibitory activity against cancer cell lines, structure-activity relationships were investigated surrounding the prenylated benzamide side chain of the natural product. Results obtained from these studies have produced the first novobiocin analogues that manifest anti-proliferative activity against several cancer cell lines.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Novobiocina/análogos & derivados , Novobiocina/farmacologia , Antineoplásicos/química , Benzamidas/síntese química , Benzamidas/farmacologia , Linhagem Celular Tumoral , Dimerização , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Novobiocina/síntese química , Relação Estrutura-AtividadeRESUMO
Recently, we reported a useful assay for the determination of yeast Hsp90 ATPase activity. Using this assay, high-throughput screening of approximately 10,000 compounds was performed to determine the feasibility of this assay on large scale. Results from high-throughput screening indicated that the assay was reproducible (av Z-factor = 0.80) and identified 0.57% of the compounds as Hsp90 inhibitors that exhibited IC50s less than 20 microM. The structures of several of these inhibitory scaffolds are reported along with their IC50 values.
Assuntos
Adenosina Trifosfatases/antagonistas & inibidores , Adenosina Trifosfatases/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/metabolismo , Estrutura MolecularRESUMO
The Hsp90 molecular chaperone is responsible for the conformational maturation of nascent polypeptides and the rematuration of denatured proteins. Inhibition of Hsp90 represents a promising approach towards the treatment of cancer because numerous signaling cascades can be simultaneously targeted by disruption of the Hsp90-mediated process. Hsp90's ATPase activity is essential to the Hsp90-mediated protein folding process, consequently, a coupled assay was developed and optimized for determination of Hsp90's inherent ATPase activity. Using maltose phosphorylase, glucose oxidase, and horseradish peroxidase as components of this assay, a highly reproducible assay with a Z-factor of 0.87 has been produced.