Electrochemical properties of some copper-containing oxidases

Yaropolov, A. I.; Kharybin, A.N.; Emnéus, Jenny; Markó-Varga, György; Gorton, Lo

doi:10.1016/0302-4598(96)01919-8

Cited by 126 publications

(129 citation statements)

References 34 publications

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“…The electrochemistry of the Met → Gln mutant of bilirubin oxidase indicated that the intramolecular electron transfer between the type I copper center and the trinuclear copper center were accelerated as expected from the change in redox potential [84]. The electric current density due to the electron transfer between the electrode surface and type I copper of fungal laccases [80,82], bilirubin oxidase [81,84] and CueO [83] dramatically increased in the presence of dioxygen, since dioxygen was effectively converted to water without forming activated oxygen species. CueO was found to be the most promising cathodic catalyst to construct a biofuel cell because of high stability and high electric current density.…”

Section: Function Of Type I Copper In Multicopper Oxidasesmentioning

confidence: 94%

“…The redox potential of type I copper in some MCOs has also been measured electrochemically [79][80][81][82][83][84], although a molecular mass higher than 50 kDa is exceptionally unfavorable for obtaining clear electrochemical responses. Direct electrochemistry using pyrolytic graphite as a working electrode or mediated electrochemistry using Au electrodes modified with an appropriate promoter by self assembly permit the measurement of the redox potential of type I copper, when the MCO molecules take the appropriate orientation on the electrode surface and electric communication between the electrode and type I copper becomes possible.…”

Section: Properties Of Type I Copper In Multicopper Oxidasesmentioning

confidence: 99%

“…Direct electrochemistry using pyrolytic graphite as a working electrode or mediated electrochemistry using Au electrodes modified with an appropriate promoter by self assembly permit the measurement of the redox potential of type I copper, when the MCO molecules take the appropriate orientation on the electrode surface and electric communication between the electrode and type I copper becomes possible. Thus, the redox potential of the type I coppers of plant and fungal laccases [80], ascorbate oxidase [79], bilirubin oxidase [81,84], CeuO [83] have been electrochemically determined, although the association of these proteins and the electrode sometimes gave slightly different values from those determined by the titration method. The shorter the distance of type I copper from the protein surface, the better the electrochemical response.…”

Section: Properties Of Type I Copper In Multicopper Oxidasesmentioning

confidence: 99%

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Structure and function of type I copper in multicopper oxidases

Sakurai

Kataoka

2007

Cell. Mol. Life Sci.

128

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Abstract. The type I copper center in multicopper oxidases is constructed from 1Cys2His and weakly coordinating 1Met or the non-coordinating 1Phe/1Leu, and it exhibits spectral properties and an alkaline transition similar to those of the blue copper center in blue copper proteins. Since the type I copper center in multicopper oxidases is deeply buried inside the protein molecule, electron transfers to and from type I copper are performed through specific pathways: the hydrogen bond between an amino acid located at the substrate binding site and a His residue coordinating type I copper, and the His-Cys-His sequence connecting the type I copper center and the trinuclear copper center comprised of a type II copper and a pair of type III coppers. The intramolecular electron transfer rates can be tuned by mutating the fourth ligand of type I copper. Further, mutation at the Cys ligand gives a vacant type I copper center and traps the reaction intermediate during the four-electron reduction of dioxygen.

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Section: Function Of Type I Copper In Multicopper Oxidasesmentioning

confidence: 94%

Section: Properties Of Type I Copper In Multicopper Oxidasesmentioning

confidence: 99%

Section: Properties Of Type I Copper In Multicopper Oxidasesmentioning

confidence: 99%

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Structure and function of type I copper in multicopper oxidases

Sakurai

Kataoka

2007

Cell. Mol. Life Sci.

128

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“…In spite of the fact that SPGE is well-characterized [57] and widely used for MCO studies [39,79,80], it is not a very good electrode for fundamental bioelectrochemical investigations of redox proteins.…”

Section: Myrothecium Verrucaria Boxmentioning

confidence: 99%

On the Possibility of Uphill Intramolecular Electron Transfer in Multicopper Oxidases: Electrochemical and Quantum Chemical Study of Bilirubin Oxidase

et al. 2012

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The catalytic cycle of multicopper oxidases (MCOs) involves intramolecular electron transfer (IET) from the Cu‐T1 copper ion, which is the primary site of the one‐electron oxidations of the substrate, to the trinuclear copper cluster (TNC), which is the site of the four‐electron reduction of dioxygen to water. In this study we report a detailed characterization of the kinetic and electrochemical properties of bilirubin oxidase (BOx) – a member of the MCO family. The experimental results strongly indicate that under certain conditions, e.g. in alkaline solutions, the IET can be the rate‐limiting step in the BOx catalytic cycle. The data also suggest that one of the catalytically relevant intermediates (most likely characterized by an intermediate oxidation state of the TNC) formed during the catalytic cycle of BOx has a redox potential close to 0.4 V, indicating an uphill IET process from the T1 copper site (0.7 V) to the Cu‐T23. These suggestions are supported by calculations of the IET rate, based on the experimentally observed Gibbs free energy change and theoretical estimates of reorganization energy obtained by combined quantum and molecular mechanical (QM/MM) calculations.

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“…Later this occurrence was identified in many other redox enzymes including different BMCO, e.g. ascorbate oxidase [8,9] and bilirubin oxidase [10,11], as well as fungal [12][13][14][15], plant [12,16] and bacterial [17,18] Lcs. BMCO contain four copper ions which are historically classified into three types according to their spectroscopic characteristics, viz.…”

Section: Introductionmentioning

confidence: 99%

Stable ‘Floating' Air Diffusion Biocathode Based on Direct Electron Transfer Reactions Between Carbon Particles and High Redox Potential Laccase

et al. 2010

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We report on the assembly and characterisation of a high potential, stable, mediator‐less and cofactor free biocathode based on a fungal laccase (Lc), adsorbed on highly dispersed carbonaceous materials. First, the stability and activity of Trametes hirsuta Lc immobilised on different carbon particles were studied and compared to the solubilised enzyme. Based on the experimental results and a literature analysis, the carbonaceous material BM‐4 was chosen to design efficient and stable biocatalysts for the production of a ‘floating' air diffusion Lc‐based biocathode. Voltammetric characteristics and operational stability of the biocathode were investigated. The current density of oxygen reduction at the motionless biocathode in a quiet, air saturated citrate buffer (100 mM, pH 4.5, 23 °C) reached values as high as 0.3 mA cm–2 already at 0.7 V versus NHE. The operational stability of the biocathode depended on the current density of the device. For example, at low current density (20 μA cm–2), the biocathode lost only 5× of its initial power after 1 month of continuous operation. However, when the device was polarised at 150 mV it lost more than 32× of its initial power in just 10 min. We also found that co‐immobilisation of Lc and peroxidase on highly dispersed carbon materials could protect the biocatalyst from rapid inactivation by hydrogen peroxide produced during electrocatalytic reactions at high‐current densities.

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Electrochemical properties of some copper-containing oxidases

Cited by 126 publications

References 34 publications

Structure and function of type I copper in multicopper oxidases

Structure and function of type I copper in multicopper oxidases

On the Possibility of Uphill Intramolecular Electron Transfer in Multicopper Oxidases: Electrochemical and Quantum Chemical Study of Bilirubin Oxidase

Stable ‘Floating' Air Diffusion Biocathode Based on Direct Electron Transfer Reactions Between Carbon Particles and High Redox Potential Laccase

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