Artículo
Cu(II)-reduction by Escherichia coli cells is dependent on respiratory chain components
Volentini, Sabrina Inès
; Farias, Ricardo Norberto
; Rodríguez Montelongo, Luisa; Rapisarda, Viviana Andrea
Fecha de publicación:
10/2011
Editorial:
Springer
Revista:
Biometals
ISSN:
0966-0844
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Copper is both an essential nutrient and a toxic element able to catalyze free radicals formation which damage lipids and proteins. Although the available copper redox species in aerobic environment is Cu(II), proteins that participate in metal homeostasis use Cu(I). With isolated Escherichia coli membranes, we have previously shown that electron flow through the respiratory chain promotes cupric ions reduction by NADH dehydrogenase-2 and quinones. Here, we determined Cu(II)-reductase activity by whole cells using strains deficient in these respiratory chain components. Measurements were done by the appearance of Cu(I) in the supernatants of cells exposed to sub-lethal Cu(II) concentrations. In the absence of quinones, the Cu(II)-reduction rate decreased ~70% in respect to the wild-type strain, while this diminution was about 85% in a strain lacking both NDH-2 and quinones. The decrease was ~10% in the absence of only NDH-2. In addition, we observed that quinone deficient strains failed to grow in media containing either excess or deficiency of copper, as we have described for NDH-2 deficient mutants. Thus, the Cu(II)-reduction by E. coli intact cells is mainly due to quinones and to a lesser extent to NDH-2, in a quinone-independent way. To our knowledge, this is the first in vivo demonstration of the involvement of E. coli respiratory components in the Cu(II)-reductase activity which contributes to the metal homeostasis.
Palabras clave:
Cupric Ion Reduction
,
Nadh Dehydrogenase-2
,
Quinones
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(CCT - NOA SUR)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - NOA SUR
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - NOA SUR
Articulos(INSIBIO)
Articulos de INST.SUP.DE INVEST.BIOLOGICAS
Articulos de INST.SUP.DE INVEST.BIOLOGICAS
Citación
Volentini, Sabrina Inès; Farias, Ricardo Norberto; Rodríguez Montelongo, Luisa; Rapisarda, Viviana Andrea; Cu(II)-reduction by Escherichia coli cells is dependent on respiratory chain components; Springer; Biometals; 24; 5; 10-2011; 827-835
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