Screen-printed graphite macroelectrodes for the direct electron transfer of cytochrome c: A deeper study of the effect of pH on the conformational states, immobilization and peroxidase activity
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Título: | Screen-printed graphite macroelectrodes for the direct electron transfer of cytochrome c: A deeper study of the effect of pH on the conformational states, immobilization and peroxidase activity |
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Autor/es: | Gomez-Mingot, Maria | Montiel, Vicente | Banks, Craig E. | Iniesta, Jesus |
Grupo/s de investigación o GITE: | Electroquímica Aplicada y Electrocatálisis |
Centro, Departamento o Servicio: | Universidad de Alicante. Departamento de Química Física | Universidad de Alicante. Instituto Universitario de Electroquímica |
Palabras clave: | Cytochrome c | Screen-printed electrodes | Direct electron transfer | Conformational states | Peroxidase activity |
Área/s de conocimiento: | Química Física |
Fecha de publicación: | 2-ene-2014 |
Editor: | Royal Society of Chemistry |
Cita bibliográfica: | Analyst. 2013, Accepted Manuscript. doi:10.1039/C3AN02137H |
Resumen: | The direct electron transfer of cytochrome c has been studied at screen-printed graphite macroelectrodes without recourse to mediators or the need of any electrode pre-treatments as is commonly employed within the literature. A wide range of pH values from 2.0 to 11.0 have been explored upon the electrochemical response of cytochrome c and different voltammetric signatures have been observed. The direct electron transfer of the alkaline transition of cytochrome c was found impeded within alkaline media leading to either an irreversible redox process or even no voltammetric responses. In acidic aqueous media the electrochemical process is observed to undergo a mixed diffusion and adsorption controlled process rather than a purely difusional process of the native conformation as observed at pH 7.0. Interestingly, at pH 3.5 a new conformational state is revealed in cooperation with the native conformation. The immobilization of the protein was satisfactorily obtained with a simple method by cycling the protein at specific solution pH values allowing amperometric responses to be obtained and gives rise to useful pseudo-peroxidase activity for sensing H2O2. Apparent Michaelis Menten constant values (Km) were calculated via the Lineweaver-Burk method with deduced values of 25 ± 4, 98 ± 12 and 230 ± 30 mM, respectively for pH values of 2.0, 3.0 and 7.0. Such work is important for those utilising cytochrome c in bio-electrochemical and related applications. |
Patrocinador/es: | Financial support from The Ministry of Science and Technology (project CTQ2010-18570). |
URI: | http://hdl.handle.net/10045/34942 |
ISSN: | 0003-2654 (Print) | 1364-5528 (Online) |
DOI: | 10.1039/C3AN02137H |
Idioma: | eng |
Tipo: | info:eu-repo/semantics/article |
Derechos: | © Royal Society of Chemistry 2014 |
Revisión científica: | si |
Versión del editor: | http://dx.doi.org/10.1039/C3AN02137H |
Aparece en las colecciones: | INV - LEQA - Artículos de Revistas |
Archivos en este ítem:
Archivo | Descripción | Tamaño | Formato | |
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2014_Gomez-Mingot_etal_Analyst.pdf | Accepted Manuscript (acceso abierto) | 990,76 kB | Adobe PDF | Abrir Vista previa |
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