scholarly journals Oxidation of 2-nitropropane by horseradish peroxidase. Involvement of hydrogen peroxide and of superoxide in the reaction mechanism

1978 ◽  
Vol 175 (2) ◽  
pp. 601-606 ◽  
Author(s):  
Johan De Rycker ◽  
Barry Halliwell
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Reaction Mechanism ◽  
Horseradish Peroxidase ◽  
Aqueous Solutions ◽  
Oxidation Reaction ◽  
Superoxide Ion ◽  
Radical Species ◽  
Ph Optimum ◽  
Nitro Aromatics

Incubation of aqueous solutions of 2-nitropropane in air causes a slow oxidation reaction that generates H2O2. Purified horseradish peroxidase catalyses the oxidation of such preincubated 2-nitropropane solutions according to the equation: [Formula: see text] The pH optimum is 4.5 and Km for 2-nitropropane is 16mm. Other nitroalkanes or nitro-aromatics tested are not oxidized at significant rates by peroxidase. H2O2 or 2,4-dichlorophenol increases the rate of 2-nitropropane oxidation by peroxidase. Catalase inhibits the reaction completely. Superoxide dismutase or mannitol, a scavenger of the hydroxyl radical, OH., each inhibits partially. Aniline and guaiacol are also powerful inhibitors of 2-nitropropane oxidation. It is suggested that peroxidase uses the traces of H2O2 generated during preincubation of 2-nitropropane to catalyse oxidation of this substrate into a radical species that can reduce O2 to the superoxide ion, O2−..O2−., or OH. derived from it, then appears to react with more nitropropane, generating further radicals and H2O2 to continue the oxidation. Inhibition by aniline and guaiacol seems to be due to a competition for H2O2.

scholarly journals Studies on horseradish peroxidase in dimethyl sulphoxide/water mixtures. The activation of hydrogen peroxide and the binding of fluoride

1979 ◽  
Vol 179 (2) ◽  
pp. 273-280 ◽  
Author(s):  
P A Adams ◽  
D A Baldwin ◽  
G S Collier ◽  
J M Pratt
Keyword(s):  
Hydrogen Peroxide ◽  
Enzyme Activity ◽  
Horseradish Peroxidase ◽  
Aqueous Solutions ◽  
Similar Pattern ◽  
Solvent Mixture ◽  
Dimethyl Sulphoxide ◽  
Stock Solutions ◽  
Activation Of Hydrogen Peroxide

We studied the variation in spectra and in reactivity towards H2O2 of solutions of horseradish peroxidase in dimethyl sulphoxide/water mixtures, obtained by diluting stock solutions of the enzyme in either water or dimethyl sulphoxide, and assayed the enzyme activity and studied the binding of F- by the peroxidase in 65% (v/v) dimethyl sulphoxide. A broadly similar pattern of changes is observed whether one starts from water or from dimethyl sulphoxide; the changes are essentially reversible, though hysteresis is observed. When the dimethyl sulphoxide content of the solvent mixture is increased, the peroxidase retains its ability to activate H2O2 up to 74% (v/v) dimethyl sulphoxide. The peroxidase in 65% (v/v) dimethyl sulphoxide binds F- together with a proton (or the equivalent loss of HO-), as already established for aqueous solutions. We point out that the occurrence in such solutions of both the ability to activate H2O2 and the inability to bind F- without taking up H+ or losing HO- supports the proposed mechanism for activating H202, whereby the protein binds the substrate in the form of the much more reactive HO2-.

scholarly journals The amplex red/horseradish peroxidase assay requires superoxide dismutase to measure hydrogen peroxide in the presence of NAD(P)H

2020 ◽  
Vol 54 (8-9) ◽  
pp. 620-628
Author(s):  
Vladimir Mishin ◽  
Diane E. Heck ◽  
Debra L. Laskin ◽  
Jeffrey D. Laskin
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Horseradish Peroxidase ◽  
Amplex Red

scholarly journals A MORE SENSITIVE AND SPECIFIC HISTOCHEMICAL PEROXIDASE STAIN FOR THE LOCALIZATION OF CELLULAR ANTIGEN BY THE ENZYME-ANTIBODY CONJUGATE METHOD

1974 ◽  
Vol 22 (12) ◽  
pp. 1135-1140 ◽  
Author(s):  
E. EARL WEIR ◽  
THOMAS G. PRETLOW ◽  
ANNETTE PITTS ◽  
EDWIN E. WILLIAMS
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Sensitivity And Specificity ◽  
Ph Optimum ◽  
Concentration Time ◽  
Antibody Conjugate ◽  
Cellular Antigen

In an attempt to increase the sensitivity and specificity of immunohistochemical procedures using peroxidase-labeled antibody, we have modified the technique. This modification takes advantage of the pH optimum of horseradish peroxidase. The best buffer salts, hydrogen peroxide concentration, time of staining, fixation after incubation with labeled antibody and counterstains were determined empirically. Compounds similar to the substrate are known to undergo photooxidation, and specificity was enhanced by keeping the solutions in the dark.

scholarly journals Monitoring the heme iron state in horseradish peroxidase to detect ultratrace amounts of hydrogen peroxide in alcohols

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 9901-9910
Author(s):  
Raheleh Ravanfar ◽  
Alireza Abbaspourrad
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Oxidative Damage ◽  
Heme Iron ◽  
Aqueous Systems ◽  
Iron State ◽  
Low Concentrations

Despite the importance of hydrogen peroxide (H2O2) in initiating oxidative damage and its connection to various diseases, the detection of low concentrations of H2O2 (<10 μM) is still limited using current methods, particularly in non-aqueous systems.

scholarly journals The Reaction of Ferrous Horseradish Peroxidase with Hydrogen Peroxide

1970 ◽  
Vol 245 (9) ◽  
pp. 2409-2413
Author(s):  
Robert W. Noble ◽  
Quentin H. Gibson
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase

Effect of Val 73 → Trp Mutation on the Reaction of “Cambialistic” Superoxide Dismutase fromPropionibacterium shermaniiwith Hydrogen Peroxide

1997 ◽  
Vol 345 (1) ◽  
pp. 156-159 ◽  
Author(s):  
R. Gabbianelli ◽  
A. Battistoni ◽  
C. Capo ◽  
F. Polticelli ◽  
G. Rotilio ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase
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