A novel application of horseradish peroxidase: Oxidation of alcohol ethoxylate to alkylether carboxylic acid

2008 ◽  
Vol 19 (12) ◽  
pp. 1411-1414 ◽  
Author(s):  
Li Fei Zhi ◽  
Qiu Xiao Li ◽  
Yun Ling Li
Keyword(s):  
Carboxylic Acid ◽  
Horseradish Peroxidase ◽  
Alcohol Ethoxylate ◽  
Peroxidase Oxidation

Horseradish Peroxidase Oxidation of Tyrosine-Containing Peptides and Their Subsequent Polymerization:  A Kinetic Study†

Biochemistry ◽  
1997 ◽  
Vol 36 (28) ◽  
pp. 8504-8513 ◽  
Author(s):  
Thierry Michon ◽  
Michel Chenu ◽  
Nicolas Kellershon ◽  
Michel Desmadril ◽  
Jacques Guéguen
Keyword(s):  
Horseradish Peroxidase ◽  
Kinetic Study ◽  
Peroxidase Oxidation

scholarly journals A study of the supposed hydroxylation of tyrosine catalysed by peroxidase

1976 ◽  
Vol 153 (2) ◽  
pp. 403-408 ◽  
Author(s):  
P I Smith ◽  
G A Swan
Keyword(s):  
Ascorbic Acid ◽  
Phenolic Compounds ◽  
Carboxylic Acid ◽  
Horseradish Peroxidase ◽  
Spectral Changes

The claim that peroxidase (rather than tyrosinase) is the enzyme responsible for the conversion of tyrosine into dopa (3,4-dihydroxyphenylalanine) in melanogenesis was investigated. The spectral changes that occurred during the action of horseradish peroxidase in the presence of H2O2 on dopa, tyrosine and mixtures of dopa with tyrosine or other phenolic compounds were studied. The effect of ascorbic acid or dihydroxyfumaric acid on some of these changes was also investigated. No evidence was found that tyrosine was hydroxylated by peroxidase in the presence of H2O2 and dopa as cofactor, although tyrosine or other phenolic compounds increased the rate of oxidation of dopa to dopachrome (indoline-5,6-quinone-2-carboxylic acid). Peroxidase was, however, effective in oxidizing tyrosine to dopa in the presence of dihydroxyfumaric acid and oxygen.

scholarly journals Time-resolved EPR investigation of oxygen and temperature effects on synthetic eumelanin

2010 ◽  
Vol 24 (3-4) ◽  
pp. 289-295 ◽  
Author(s):  
Fosca Conti ◽  
Lucia Panzella ◽  
Alessandra Napolitano ◽  
Marco d᾽Ischia ◽  
Antonio Toffoletti
Keyword(s):  
Carboxylic Acid ◽  
Horseradish Peroxidase ◽  
Excited States ◽  
Temperature Effects ◽  
Polarization Pattern ◽  
Radical Pairs ◽  
Time Resolved ◽  
Triplet Mechanism ◽  
Spin Polarized ◽  
Triplet Excited States

Synthetic eumelanin produced using 5,6-dihydroxyindole-2-carboxylic acid as precursor and H2O2/horseradish peroxidase as oxidative reagent, in form of dry powder, has been investigated under photoexcitation by TR-EPR spectroscopy. The formation of spin polarized radical pairs from triplet excited states of melanin has been observed both in absence and in presence of oxygen and has been followed as a function of the temperature in the range 140–290 K. The triplet mechanism explains the observed polarization pattern in net emission. In the presence of oxygen new radical pairs are formed by interaction of melanin with molecular oxygen.

scholarly journals HORSERADISH PEROXIDASE CATALYZED DEGRADATION OF BROMOPHENOL BLUE DYE

2020 ◽  
Vol 64 (1) ◽  
pp. 93-98
Author(s):  
Anna A. Solovyeva ◽  
Thi Trinh Pham ◽  
Olga E. Lebedeva ◽  
Maria N. Ustinova
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Dye Degradation ◽  
Enzymatic Reaction ◽  
Oxidative Degradation ◽  
Bromophenol Blue ◽  
Blue Dye ◽  
Time Interval ◽  
Bromophenol Blue Dye ◽  
Peroxidase Oxidation

In this study, the oxidative destruction of bromophenol blue dye with hydrogen peroxide was carried out at pH 4.0-4.1 in the presence of a commercial horseradish peroxidase, as well as peroxidase isolated directly from horseradish roots (Armoracia rusticana). To determine peroxidase activity, a model reaction of the oxidation of phenol to quinone was used. With a dye concentration of 32.7 μM, the optimal concentration of hydrogen peroxide was 0.04 mM at peroxidase concentration of 1.15 nM. The optimal temperature of the enzymatic reaction was determined: at 23 °С for 10 min 90% of the dye was exposed to destruction. When the temperature rises to 50 °С, the reaction rate decreases, and the degree of destruction is 56% for the same time interval. It was shown that the initial rate of peroxidase oxidation of bromophenol blue follows Michaelis-Menten equation. The kinetic parameters of the enzymatic reaction were determined by linearizing Michaelis-Menten equation in Lineweaver-Burk coordinates. It was found that for the peroxidase oxidation reaction of bromophenol blue Michaelis constant and maximum rate were 42.7 μM and 57.5 μM·min–1, respectively. In this work, а high percentage of dye degradation was also achieved when using peroxidase isolated from horseradish roots. The experiments were conducted at a temperature of 30оС and pH 4.1. With the increase in the volume of the extract from 0.1 to 0.2 ml, the percentage decolorization increases from 75% to 90%. The results demonstrate the high degradation efficiency of bromophenol blue with the participation of the commercial horseradish peroxidase and peroxidase isolated from horseradish roots. Enzymatic oxidative degradation can be considered as an alternative to biodegradation.

scholarly journals Phenothiazines are slowly oxidizable substrates of horseradish peroxidase

2011 ◽  
Vol 57 (5) ◽  
pp. 544-553 ◽  
Author(s):  
T.V. Rogozhina ◽  
V.V. Rogozhin
Keyword(s):  
Steady State ◽  
Horseradish Peroxidase ◽  
Reaction Medium ◽  
Substrate Oxidation ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Steady State Kinetic ◽  
State Kinetic ◽  
Full Conversion ◽  
Peroxidase Oxidation

Reactions of peroxidase oxidation of triftazine and thioproperazine have been investigated in the presence of horseradish peroxidase using steady state kinetic methods. It has been shown that phenothiazines are slowly oxidizable substrates for horseradish peroxidase. kcat and Km values have been determined in the range of pH from 4.5 to 7.5. The study of co-oxidation of phenothiazines and o-dianisidine (ODN) revealed that in the presence of aminazine and ODN in the reaction medium both substances follow sequential oxidation. ODN oxidation was not observed until full conversion of aminazine. At pH 4.5-5.5 thioproperazine bound to the enzyme-substrate complex and caused a nticompetitive inhibition of peroxidase. At pH>5.5 sequential substrate oxidation with preferential thioproperazine conversion occurred. In the range of pH from 4.5 to 7.5 triftazine did not influence ODN oxidation.

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