title: A catalytic approach to estimate the redox potential of heme-peroxidases.
abstract: The redox potential of heme-peroxidases varies according to a combination of structural components within the active site and its vicinities. For each peroxidase, this redox potential imposes a thermodynamic threshold to the range of oxidizable substrates. However, the instability of enzymatic intermediates during the catalytic cycle precludes the use of direct voltammetry to measure the redox potential of most peroxidases. Here we describe a novel approach to estimate the redox potential of peroxidases, which directly depends on the catalytic performance of the activated enzyme. Selected p-substituted phenols are used as substrates for the estimations. The results obtained with this catalytic approach correlate well with the oxidative capacity predicted by the redox potential of the Fe(III)/Fe(II) couple.
authors: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico. maa@ibt.unam.mx
authors: Marcela
authors: M
authors: Ayala
authors: Rosa
authors: R
authors: Roman
authors: Rafael
authors: R
authors: Vazquez-Duhalt
mesh_terms: D000818:Animals; D001487:Basidiomycota / Q000201:enzymology; D002384:Catalysis; D002417:Cattle; D003302:Coprinus / Q000201:enzymology; D004563:Electrochemistry / Q000379:methods; D006418:Heme / Q000737:chemistry* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000737:chemistry* / Q000378:metabolism; D010636:Phenols / Q000737:chemistry / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology; D013045:Species Specificity; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D010636:Phenols; D013438:Sulfhydryl Compounds; D006418:Heme; D006861:Hydrogen Peroxide; D009195:Peroxidase