The pH and temperature dependences of the reduction potentials of Alcaligenes denitrificans (Ade), Pseudomonas aeruginosa (Pae), Alcaligenes faecalis (Afa), Alcaligenes sp. (Asp) and Bordetella bronchiseptica (Bbr) azurins have been determined by spectroelectrochemistry. Potentials at pH 8.0 (25 °C, μ 0.1 M, NaPi) are: 267.0 (Ade); 291.9 (Pae); 251.5 (Afa); 278.1 (Asp); 250.3 (Bbr) mV versus NHE. The variations in the potentials with pH are interpreted in terms of interactions between the copper site and titrating histidine residues. Variations in the reduction potential of Bbr azurin with both pH and temperature indicate that the copper site is distorted significantly by a redox-linked conformational change in this protein.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry