Artículo
The homopentameric chlorite dismutase from Magnetospirillum sp
Freire, Diana M.; Rivas, Maria Gabriela
; Dias, André M.; Lopes, Ana T.; Costa, Cristina; Santos Silva, Teresa; Van Doorslaer, Sabine; González, Pablo Javier
Fecha de publicación:
07/2015
Editorial:
Elsevier
Revista:
Journal of Inorganic Biochemistry
ISSN:
0162-0134
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Chlorite dismutase (Cld) is a b-type hemecontaining enzymethat catalyzes the reduction of chlorite into chloride plus dioxygen. This enzyme has gained attention because it can be used in the development of bioremediation processes, biosensors, and controlled dioxygen production. In the present work, Cld was purified from Magnetospirillum sp. cells cultured anaerobically with acetate/perchlorate until stationary phase. Biochemical, spectroscopic and X-ray crystallography methods showed that Cld from Magnetospirillum sp. is a ~140 kDa homopentamer comprising ~27.8 kDa monomers. Preliminary X-ray crystallography studies confirmed the quaternary structure and the presence of one b-type heme per monomer. The EPR spectroscopic signature of the as-purified Cld samples is affected by the buffer composition used during the purification. Potassium phosphate buffer is the only buffer that affected neither the spectral nor the kinetic properties of Cld. Kinetic studies in solution revealed that Cld from Magnetospirillum sp. decomposes chlorite at high turnover rates with optimal pH 6.0. A temperature below 10 °C is required to avoid enzyme inactivation due to cofactor bleaching during turnover, and to achieve full substrate consumption. Cld kinetic parameters were not affected when kinetic assays were performed in the presence of air or under argon atmosphere, but chloride is a weak mixed inhibitor that modifies the EPR signal of as-prepared samples.
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Identificadores
Colecciones
Articulos(CCT - SANTA FE)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - SANTA FE
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - SANTA FE
Citación
Freire, Diana M.; Rivas, Maria Gabriela; Dias, André M.; Lopes, Ana T.; Costa, Cristina; et al.; The homopentameric chlorite dismutase from Magnetospirillum sp; Elsevier; Journal of Inorganic Biochemistry; 151; 7-2015; 1-9
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