scholarly journals High Redox Potential Cathode Based on Laccase Covalently Attached to Gold Electrode

2011 ◽  
Vol 115 (27) ◽  
pp. 13420-13428 ◽  
Author(s):  
Marcos Pita ◽  
Cristina Gutierrez-Sanchez ◽  
David Olea ◽  
Marisela Velez ◽  
Cristina Garcia-Diego ◽  
...  
Keyword(s):  
Redox Potential ◽  
Gold Electrode ◽  
High Redox Potential

A few key residues determine the high redox potential shift in azurin mutants

2015 ◽  
Vol 13 (45) ◽  
pp. 11003-11013 ◽  
Author(s):  
Laura Zanetti-Polzi ◽  
Carlo A. Bortolotti ◽  
Isabella Daidone ◽  
Massimiliano Aschi ◽  
Andrea Amadei ◽  
...  
Keyword(s):  
Redox Potential ◽  
Potential Shift ◽  
Key Residues ◽  
High Redox Potential

The changes in the redox potential of Azurin upon mutation stem from the effects of a few key residues, including non-mutated ones, rather than being the result of a generalized rearrangement.

Electronic Characterization of the Oxidized State of the Blue Copper Protein Rusticyanin by1H NMR:  Is the Axial Methionine the Dominant Influence for the High Redox Potential?†

Biochemistry ◽  
2001 ◽  
Vol 40 (3) ◽  
pp. 837-846 ◽  
Author(s):  
Antonio Donaire ◽  
Beatriz Jiménez ◽  
José-María Moratal ◽  
John F. Hall ◽  
S. Samar Hasnain
Keyword(s):  
Redox Potential ◽  
Blue Copper Protein ◽  
Blue Copper ◽  
Copper Protein ◽  
Dominant Influence ◽  
High Redox Potential

scholarly journals Purification and Partial Characterization of a Thermostable Laccase from Pycnoporus sanguineus CS-2 with Ability to Oxidize High Redox Potential Substrates and Recalcitrant Dyes

10.5772/56374 ◽  
2013 ◽  
Author(s):  
Sergio M. Salcedo Martnez ◽  
Guadalupe Gutirrez-Soto ◽  
Carlos F. Rodriguez Garza ◽  
Tania J. Villarreal Galvan ◽  
Juan F. Contreras Cordero ◽  
...  
Keyword(s):  
Redox Potential ◽  
Partial Characterization ◽  
Pycnoporus Sanguineus ◽  
High Redox Potential

scholarly journals Titanium-based potassium-ion battery positive electrode with extraordinarily high redox potential

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Stanislav S. Fedotov ◽  
Nikita D. Luchinin ◽  
Dmitry A. Aksyonov ◽  
Anatoly V. Morozov ◽  
Sergey V. Ryazantsev ◽  
...  
Keyword(s):  
Redox Potential ◽  
Potassium Ion ◽  
Positive Electrode ◽  
High Redox Potential

The effect of pH and complexation on redox reactions between RS• radicals and flavins

1984 ◽  
Vol 62 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Rizwan Ahmad ◽  
David A. Armstrong
Keyword(s):  
Redox Potential ◽  
Linear Function ◽  
Redox Reactions ◽  
Flavin Adenine Dinucleotide ◽  
Protonated Form ◽  
Redox Properties ◽  
The Other ◽  
Effect Of Ph ◽  
Other Hand ◽  
High Redox Potential

Elementary considerations indicate that thiol radicals, RS•, should have a high redox potential [Formula: see text][Formula: see text]However, the equilibrium [4],[Formula: see text]which is established in the presence of excess RS−, would convert RS•to [Formula: see text] which is a reducing species. Experimentally it was demonstrated that thiol radicals made by γ radiolysis of β-mercaptoethanol solutions effected two-electron oxidation of dihydroflavin FlH2 at pH 6.3 and of FlH− at pH 8. On the other hand, [Formula: see text] readily reduced Fl to FlH2 or FlH− as expected. At pH 9, photostationary states were established after a few minutes radiolysis and the ratios [FlH−]ss/[Fl]ss were a function of [Formula: see text] The main reactions occurring were:[Formula: see text]The values of k19 and k22 were both large. The ratio k19/k22 was ∼0.8 for lumiflavin and ∼0.3 for flavin adenine dinucleotide. The cyclic disulphide anions of lipoamide and dithiothreitol [Formula: see text] also effected two-electron reductions of flavins. However, the protonated form of [Formula: see text] oxidized FlH2, and the photostationary ratio [FlH−]ss/[Fl]ss was an approximate linear function of [Formula: see text]. The implications of the observed changes in redox properties of sulphur radicals on complexation with RS− and protonation were briefly considered.Des considérations élémentaires indiquent que les radicaux thiyles, RS•, doivent avoir un potentiel rédox élevé [Formula: see text][Formula: see text]

Comparative analysis of gene sequences of three high-redox-potential laccases from basidiomycetes

2007 ◽  
Vol 417 (1) ◽  
pp. 348-351 ◽  
Author(s):  
E. A. Cherkashin ◽  
E. V. Stepanova ◽  
E. O. Landesman ◽  
O. V. Koroleva ◽  
V. I. Tishkov
Keyword(s):  
Comparative Analysis ◽  
Redox Potential ◽  
Gene Sequences ◽  
High Redox Potential

Circular dichroism and redox properties of high redox potential ferredoxins

Biochemistry ◽  
1985 ◽  
Vol 24 (10) ◽  
pp. 2542-2549 ◽  
Author(s):  
Craig T. Przysiecki ◽  
Terrance E. Meyer ◽  
Michael A. Cusanovich
Keyword(s):  
Circular Dichroism ◽  
Redox Potential ◽  
Redox Properties ◽  
Circular Dichroïsm ◽  
High Redox Potential

scholarly journals The role of double covalent flavin binding in chito-oligosaccharide oxidase from Fusarium graminearum

2008 ◽  
Vol 413 (1) ◽  
pp. 175-183 ◽  
Author(s):  
Dominic P. H. M. Heuts ◽  
Remko T. Winter ◽  
Gerke E. Damsma ◽  
Dick B. Janssen ◽  
Marco W. Fraaije
Keyword(s):  
Redox Potential ◽  
Fusarium Graminearum ◽  
Covalent Binding ◽  
Site Directed Mutagenesis ◽  
Wild Type ◽  
Covalent Bonds ◽  
Regioselective Oxidation ◽  
Flavin Binding ◽  
High Redox Potential

ChitO (chito-oligosaccharide oxidase) from Fusarium graminearum catalyses the regioselective oxidation of N-acetylated oligosaccharides. The enzyme harbours an FAD cofactor that is covalently attached to His94 and Cys154. The functional role of this unusual bi-covalent flavin–protein linkage was studied by site-directed mutagenesis. The double mutant (H94A/C154A) was not expressed, which suggests that a covalent flavin–protein bond is needed for protein stability. The single mutants H94A and C154A were expressed as FAD-containing enzymes in which one of the covalent FAD–protein bonds was disrupted relative to the wild-type enzyme. Both mutants were poorly active, as the kcat decreased (8.3- and 3-fold respectively) and the Km increased drastically (34- and 75-fold respectively) when using GlcNac as the substrate. Pre-steady-state analysis revealed that the rate of reduction in the mutant enzymes is decreased by 3 orders of magnitude when compared with wild-type ChitO (kred=750 s−1) and thereby limits the turnover rate. Spectroelectrochemical titrations revealed that wild-type ChitO exhibits a relatively high redox potential (+131 mV) and the C154A mutant displays a lower potential (+70 mV), while the H94A mutant displays a relatively high potential of approximately +164 mV. The results show that a high redox potential is not the only prerequisite to ensure efficient catalysis and that removal of either of the covalent bonds may perturb the geometry of the Michaelis complex. Besides tuning the redox properties, the bi-covalent binding of the FAD cofactor in ChitO is essential for a catalytically competent conformation of the active site.

Sign in / Sign up

Export Citation Format

Share Document