INVESTIGADORES
VINCENT Paula Andrea
congresos y reuniones científicas
Título:
ENTEROBACTIN SIDEROPHORE IS INVOLVED IN E. coli COPPER DETOXIFICATION
Autor/es:
DAIANA ROMINA PERALTA ; PRISCILLA ROMINA DE GREGORIO ; NATALIA SOLEDAD CÓRBALÁN; MARÍA FERNANDA POMARES ; CONRADO ADLER; PAULA VINCENT
Reunión:
Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017
Resumen:
Copper is a metal that catalyzes the formation of highly reactiveoxygen species (ROS) in cell through Fenton-like reaction, leadingto an oxidative damage in lipids, DNA and proteins. Previous reports indicate that catecholate-containing molecules such as E. colienterobactin siderophore, can react with Cu2+ and reduce it to Cu+.Copper reduction by enterobactin would result toxic because lead tofacilitate Cu+ uptake and increased ROS production into cells. Wepreviously reported that enterobactin confers protection against various sources of oxidative stress such us Pseudomonad siderophorepyochelin, H2O2 and paraquat, independently of its ability to facilitateiron uptake. In this work, we analyzed the role of enterobactin incopper toxicity. To test this, we evaluated the sensitivity of different E. coli strains mutant in enterobactin metabolism to copper. Weobserved that strains impaired in enterobactin production, uptakeand hydrolysis were more susceptible to copper damage comparedto wild-type strain. Incubation in anaerobic condition or addition ofcatalase enzyme to the media protected cells lacking enterobactinfrom copper toxicity. We also found that spent medium from strainmutants showing increased catechol production, exhibited highcopper reduction activity. Nevertheless, these strains had the samecopper sensitivity than those mutants that do not produce catecholsand, in consequence, have no copper reduction activity. Besides, weobserved that entE, fepG and fes mutants showed increased ROSlevels when they grew in presence of copper compared to wild-typestrain. Enterobactin supplementation reduced copper sensitivity andROS levels in the entE mutant but did not have any protective effect on the fepG and fes mutants. Results suggest that enterobactinplays a role in copper cell detoxification and indicate that enterobactin must to be internalized and hydrolyzed to confer a full protection,possibly by reducing the metal-induced oxidative stress.Palabras clave: enterobactin ? copper - ROS ? cell protection