Mediatorless, electrochemically driven, redox transformations of T1 (type 1) and T2 copper sites in Trametes hirsuta laccase were studied by cyclic voltammetry and spectroelectrochemical redox titrations using bare gold electrode. DET (direct electron transfer) between the electrode and the enzyme was observed under anaerobic conditions. From analysis of experimental data it is concluded that the T2 copper site is in DET contact with gold. It was found that electron transfer between the gold surface and the T1 copper site progresses through the T2 copper site. From EPR measurements and electrochemical data it is proposed that the redox potential of the T2 site for high-potential 'blue' laccase is equal to about 400 mV versus NHE (normal hydrogen electrode) at pH 6.5. The hypothesis that the redox potentials of the T2 copper sites in low- and high-potential laccases/oxidases from totally different sources might be very similar, i.e. approx. 400 mV, is discussed.
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http://dx.doi.org/10.1042/BJ20041015 | DOI Listing |
J Phys Condens Matter
January 2025
Aix-Marseille University, CNRS, PIIM, F-13013 Marseille, France.
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View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Peking University Shenzhen Graduate School, Shool of Chemical Biology and Biotechnology, Lishui Road, Nanshan District, -, Shenzhen, CHINA.
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View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
Coordinatively unsaturated copper (Cu) has been demonstrated to be effective for electrifying CO reduction into C products by adjusting the coupling of C-C intermediates. Nevertheless, the intuitive impacts of ultralow coordination Cu sites on C products are scarcely elucidated due to the lack of synthetic recipes for Cu with low coordination numbers and its vulnerability to aggregation under reductive potentials. Herein, computational predictions revealed that Cu sites with higher levels of coordinative unsaturation favored the adsorption of C and C intermediates.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA.
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View Article and Find Full Text PDFInt J Mol Sci
January 2025
Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
It is challenging to handle heavy-metal-rich plants that grow in contaminated soil. The role of heavy metals in biomass on the physicochemical structure and electrochemical properties of their derived carbon has not been considered in previous research. In this study, Cu-ion hybrid nanoporous carbon (CHNC) is prepared from Cu content-contaminated biomass through subcritical hydrocharization (HTC) coupling pyrolytic activation processes.
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