Electrochemical generation of a high-valent state of cytochrome P450

2006 ◽  
Vol 100 (4) ◽  
pp. 519-523 ◽  
Author(s):  
Andrew K. Udit ◽  
Michael G. Hill ◽  
Harry B. Gray
2021 ◽  
Vol 22 (22) ◽  
pp. 12532
Author(s):  
Magalí F. Scocozza ◽  
Lígia O. Martins ◽  
Daniel H. Murgida

This work introduces a novel way to obtain catalytically competent oxyferryl species for two different dye-decolorizing peroxidases (DyPs) in the absence of H2O2 or any other peroxide by simply applying a reductive electrochemical potential under aerobic conditions. UV-vis and resonance Raman spectroscopies show that this method yields long-lived compounds II and I for the DyPs from Bacillus subtilis (BsDyP; Class I) and Pseudomonas putida (PpDyP; Class P), respectively. Both electrochemically generated high valent intermediates are able to oxidize ABTS at both acidic and alkaline pH. Interestingly, the electrocatalytic efficiencies obtained at pH 7.6 are very similar to the values recorded for regular catalytic ABTS/H2O2 assays at the optimal pH of the enzymes, ca. 3.7. These findings pave the way for the design of DyP-based electrocatalytic reactors operable in an extended pH range without the need of harmful reagents such as H2O2.


Author(s):  
François Ogliaro ◽  
Samüel P. de Visser ◽  
John T. Groves ◽  
Sason Shaik
Keyword(s):  

2001 ◽  
Vol 113 (15) ◽  
pp. 2958-2962 ◽  
Author(s):  
François Ogliaro ◽  
Samüel P. de Visser ◽  
John T. Groves ◽  
Sason Shaik
Keyword(s):  

2015 ◽  
Vol 112 (35) ◽  
pp. 10896-10901 ◽  
Author(s):  
Zhongxin Ma ◽  
Heather R. Williamson ◽  
Victor L. Davidson

The high-valent state of the diheme enzyme MauG exhibits charge–resonance (CR) stabilization in which the major species is a bis-FeIV state with one heme present as FeIV=O and the other as FeIV with axial heme ligands provided by His and Tyr side chains. In the absence of its substrate, the high-valent state is relatively stable and returns to the diferric state over several minutes. It is shown that this process occurs in two phases. The first phase is redistribution of the resonance species that support the CR. The second phase is the loss of CR and reduction to the diferric state. Thermodynamic analysis revealed that the rates of the two phases exhibited different temperature dependencies and activation energies of 8.9 and 19.6 kcal/mol. The two phases exhibited kinetic solvent isotope effects of 2.5 and 2.3. Proton inventory plots of each reaction phase exhibited extreme curvature that could not be fit to models for one- or multiple-proton transfers in the transition state. Each did fit well to a model for two alternative pathways for proton transfer, each involving multiple protons. In each case the experimentally determined fractionation factors were consistent with one of the pathways involving tunneling. The percent of the reaction that involved the tunneling pathway differed for the two reaction phases. Using the crystal structure of MauG it was possible to propose proton–transfer pathways consistent with the experimental data using water molecules and amino acid side chains in the distal pocket of the high-spin heme.


2019 ◽  
Vol 23 (04n05) ◽  
pp. 358-366 ◽  
Author(s):  
Huriye Erdogan

The intermediates operating in the cytochrome P450 catalytic cycle have been investigated for more than half a century, fascinating many enzymologists. Each intermediate has its unique role to carry out diverse oxidations. Natural time course of the catalytic cycle is quite fast, hence, not all of the reactive intermediates could be isolated during physiological catalysis. Different high-valent iron intermediates have been proposed as primary oxidants: the candidates are compound 0 (Cpd 0, [FeOOH][Formula: see text]P450) and compound I (Cpd I, Fe(IV)[Formula: see text]O por[Formula: see text]P450). Among them, the role of Cpd I in hydroxylation is fairly well understood due the discovery of the peroxide shunt. This review endeavors to put the outstanding research efforts conducted to isolate and characterize the intermediates together. In addition to spectral features of each intermediate in the catalytic cycle, the oxidizing powers of Cpd 0 and Cpd I will be discussed along with most recent scientific findings.


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