RESUMEN
Epoxide hydrolases (EHs) are present in all living organisms and catalyze the hydrolysis of epoxides to the corresponding vicinal diols. EH are involved in the metabolism of endogenous and exogenous epoxides, and thus have application in pharmacology and biotechnology. In this work, we describe the substrates and inhibitors selectivity of an epoxide hydrolase recently cloned from the filamentous fungus Trichoderma reesei QM9414 (TrEH). We also studied the TrEH urea-based inhibitors effects in the fungal growth. TrEH showed high activity on radioative and fluorescent surrogate and natural substrates, especially epoxides from docosahexaenoic acid. Using a fluorescent surrogate substrate, potent inhibitors of TrEH were identified. Interestingly, one of the best compounds inhibit up to 60% of T. reesei growth, indicating an endogenous role for TrEH. These data make TrEH very attractive for future studies about fungal metabolism of fatty acids and possible development of novel drugs for human diseases.
Asunto(s)
Epóxido Hidrolasas/fisiología , Trichoderma/metabolismo , Catálisis , Epóxido Hidrolasas/antagonistas & inhibidores , Epóxido Hidrolasas/metabolismo , Compuestos Epoxi/metabolismo , Ácidos Grasos/fisiología , Hidrólisis , Trichoderma/fisiologíaRESUMEN
En el presente trabajo se reporta la actividad inhibitoria del crecimiento bacteriano por nanopartículas de cobre cementado y de cobre comercial. Se utilizaron las cepas de Staphylococcus aureus ATCC 6538 (Gram positiva) y Escherichia coli ATCC 35218 (Gram negativa) para determinar el efecto inhibitorio mediante la concentración mínima inhibitoria de las nanopartículas diluidas en caldo de cultivo nutritivo y distribuidas en placas de ELISA. Las muestras de cobre cementado (obtenidas por procesos hidrometalúrgicos) y de cobre comercial fueron nanoestructuradas empleando un equipo de molienda mecánica. Los resultados indican que las nanopartículas de cobre comercial (a 2.5 horas de molienda) muestran acción inhibitoria del crecimiento de la cepa S. aureus y no así en la cepa E. coli. Asimismo, se determinó que la concentración mínima inhibitoria de la muestra de cobre comercial fue de 20 μg/mL frente a S. aureus. El cobre cementado (en su forma sólida y nanoestructurada) no mostró efecto inhibitorio del crecimiento en ninguna de las dos cepas estudiadas.
In this paper, we report on the bacterial growth inhibitory activity of nanoparticles of cemented and commercial copper. Strains of Staphylococcus aureus ATCC 6538 (Gram positive) and Escherichia coli ATCC 35218 (Gram negative) were used to determine the inhibitory effect by the minimal inhibitory concentration of the nanoparticles diluted in nutrient culture broth and distributed in ELISA plates. The copper cements (obtained from hydrometallurgical processes) and the commercial one were nanostructured employing a mechanical milling equipment. The results indicate that commercial copper nanoparticles (after 2.5 hours of milling) show growth inhibitory action of S. aureus strain. However, in the case of E. coli strains no inhibitory action has been observed. It was also determined that the minimal inhibitory concentration of the commercial copper is 20 μg/mL against S. aureus. On the other hand, copper cements (in solid and nanostructured form) do not show inhibitory effects.