Phenoxyl Free Radical Formation during the Oxidation of the Fluorescent Dye 2′,7′-Dichlorofluorescein by Horseradish Peroxidase
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منابع مشابه
The horseradish peroxidase-catalyzed oxidation of 3,5,3',5'-tetramethylbenzidine. Free radical and charge-transfer complex intermediates.
Benzidine and related compounds are well known substrates for horseradish peroxidase/H2O2 oxidation. Typically, two different colored products are formed. In this paper, we study the oxidation of 3,5,3',5'-tetramethylbenzidine. The first colored product is a blue charge-transfer complex of the parent diamine and the diimine oxidation product. This species exists in rapid equilibrium with the ra...
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Horseradish peroxidase catalyses the oxidation of NAD dimers, (NAD)2, to NAD+ in accordance with a reaction that is pH-dependent and requires 1 mol of O2 per 2 mol of (NAD)2. Horseradish peroxidase also catalyses the peroxidation of (NAD)2 to NAD+. In contrast, bacterial NADH peroxidase does not catalyse the peroxidation or the oxidation of (NAD)2. A free-radical mechanism is proposed for both ...
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Binding of p-cresol to native horseradish peroxidase was investigated by differential spectrophotometry, and the value lo3 Kdiss = 3 M was obtained at neutral and acid pH; binding is not competitive with that of cyanide and hydroxide. The Soret region spectrum of Compound II of the enzyme was measured in the steady state at pH 4.26, 6.89, and 10.95, and the differences were found to be too smal...
متن کاملHorseradish peroxidase mediated free radical polymerization of methyl methacrylate.
This paper reports the free radical polymerization of methyl methacrylate (MMA) catalyzed by horseradish peroxidase (HRP). A novel method was developed whereby MMA polymerization can be carried out at ambient temperatures in the presence of low concentrations of hydrogen peroxide and 2,4-pentanedione in a mixture of water and a water-miscible solvent. Polymers of MMA formed were highly stereore...
متن کاملProduction of the superoxide radical by horseradish peroxidase.
The reaction mixture contained, in a total volume of 1.00m1, enzyme, p-coumaric acid (2.5pmol), dihydroxyfumaric acid (30pmol), KH2P04 (8.3pmol) and sufficient KOH to adjust the pH to 6. Incubations were carried out for 0.5h at 25°C and caffeic acid production was assayed as described by Halliwell(l975). 100% corresponded to a rate of 60nmol of caffeic acid formed in 0.5h. Oxidation of dihydrox...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1999
ISSN: 0021-9258
DOI: 10.1074/jbc.274.40.28161