Detalhes bibliográficos
| Resumo: | This work reports the direct electrochemistry of Paracoccus pantotrophus pseudoazurin and the mediated catalysis of cytochrome c peroxidase from the same organism. The voltammetric behaviour was examined at a gold membrane electrode, and the studies were performed in the presence of calcium to enable the peroxidase activation. A formal reduction potential, E (0)', of 230 +/- 5 mV was determined for pseudoazurin at pH 7.0. Its voltammetric signal presented a pH dependence, defined by pK values of 6.5 and 10.5 in the oxidised state and 7.2 in the reduced state, and was constant up to 1 M NaCl. This small copper protein was shown to be competent as an electron donor to cytochrome c peroxidase and the kinetics of intermolecular electron transfer was analysed. A second-order rate constant of 1.4 +/- 0.2 x 10(5) M(-1) s(-1) was determined at 0 M NaCl. This parameter has a maximum at 0.3 M NaCl and is pH-independent between pH 5 and 9. |
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| Autores principais: | Sousa, P. M. Paes de |
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| Outros Autores: | Pauleta, Sofia R.; Gonçalves, M. L. Simões; Pettigrew, Graham W.; Moura, Isabel; Moura, José J. G.; Santos, Margarida M. Correia dos |
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| Assunto: | Pseudoazurin Cytochrome c peroxidase Catalysis Voltammetry Intermolecular electron transfer |
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| Ano: | 2007 |
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| País: | Portugal |
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| Tipo de documento: | artigo |
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| Tipo de acesso: | acesso aberto |
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| Instituição associada: | Universidade Nova de Lisboa |
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| Idioma: | inglês |
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| Origem: | Repositório Institucional da UNL |
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