Complexities in horseradish peroxidase-catalyzed oxidation of dihydroxyphenoxazine derivatives: appropriate ranges for pH values and hydrogen peroxide concentrations in quantitative analysis

2004 ◽  
Vol 334 (2) ◽  
pp. 290-296 ◽  
Author(s):  
Victoria Towne ◽  
Mark Will ◽  
Brent Oswald ◽  
Qinjian Zhao
Keyword(s):  
Hydrogen Peroxide ◽  
Quantitative Analysis ◽  
Horseradish Peroxidase ◽  
Ph Values ◽  
Catalyzed Oxidation

Horseradish peroxidase-mediated decolourization of Orange II: modelling hydrogen peroxide utilization efficiency at different pH values

2018 ◽  
Vol 25 (20) ◽  
pp. 19989-20002 ◽  
Author(s):  
Diego Alberto Morales Urrea ◽  
Patricia Mónica Haure ◽  
Fernando Sebastián García Einschlag ◽  
Edgardo Martín Contreras
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Utilization Efficiency ◽  
Orange Ii ◽  
Ph Values

scholarly journals Biomimetic Sulfide Oxidation by the Means of Immobilized Fe(III)-5,10,15,20-tetrakis(pentafluorophenyl)porphin under Mild Experimental Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Paolo Zucca ◽  
Gianmarco Cocco ◽  
Manuela Pintus ◽  
Antonio Rescigno ◽  
Enrico Sanjust
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Catalytic Reaction ◽  
Large Scale ◽  
Elemental Sulfur ◽  
Sulfide Oxidation ◽  
Experimental Conditions ◽  
Efficient Catalyst ◽  
Ph Values ◽  
Biomimetic Catalyst

This paper describes the oxidation of inorganic sulfide to sulfate, minimizing the formation of elemental sulfur. The described catalytic reaction uses dilute hydrogen peroxide at nearly neutral pH values in the presence of a bioinspired, heterogenized, and commercial ferriporphin. A substantial increase of the percentage of sulfide converted to sulfate is obtained in comparison with the yields obtained when working with hydrogen peroxide alone. The biomimetic catalyst also proved to be a much more efficient catalyst than horseradish peroxidase. Accordingly, it could be suitable for large-scale applications. Further studies are in progress to drive sulfate yields up to nearly quantitative.

Horseradish peroxidase/hydrogen peroxide-catalyzed oxidation of VP16-213. Identification of a new metabolite

1985 ◽  
Vol 55 ◽  
pp. 215-224 ◽  
Author(s):  
Massimo Broggini ◽  
Cosmo Rossi ◽  
Emilio Benfenati ◽  
Maurizio D'Incalci ◽  
Roberto Fanelli ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Catalyzed Oxidation

Horseradish peroxidase. XXVIII. Formation and reactivity of the alkaline form. Evidence for an enzyme–substrate complex in compound 1 formation

1978 ◽  
Vol 56 (10) ◽  
pp. 1327-1334 ◽  
Author(s):  
Dominique Job ◽  
H. Brian Dunford
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Rate Constant ◽  
Apparent Rate Constant ◽  
Ph Value ◽  
Native Enzyme ◽  
Intermediate Complex ◽  
Ph Profile ◽  
Ph Values ◽  
Saturation Kinetics

The rate of formation of 1 from horseradish peroxidase and hydrogen peroxide is investigated as a function of pH between pH9.5 and 11.5. For pH values smaller than 10, the rate depends linearly on hydrogen peroxide concentration, whereas between pH 10 and 11.5, the rate displays saturation kinetics. Evidence is presented for the formation of an intermediate complex before compound 1 formation. Two parameters were measured as a function of pH: kapp, the apparent rate constant for compound 1 formation, and kapp, the dissociation rate constant of the intermediate complex to 1. A third parameter, kapp, similar to a dissociation constant for the reaction was deduced from the two rate constants. The apparent rate constant kapp is pH independent for pH values < 9.5 and is directly affected by ionization of only one group on the native enzyme with a pK of 11. The pH dependances of kd and Kapp require a minimum of two ionizations. One corresponds to a group on the native enzyme which ionizes at a pH lower than that of the present study, the second corresponds to the ionizable group with pK of 11. For cyanide binding to horseradish peroxidase over the same pH interval, saturation kinetics were not observed, yet the pH profile for kapp exactly parallels that for formation of 1 (when corrected for the effect of the ionization of HCN) and shows an inflection at the same pH value.

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