Role of 2,4-Dichlorophenol in the Oxidation of Estradiol by Uterine and Horseradish Peroxidase

The role of 2,4-dichlorophenol in enhancing the conversion of [4- 14 C]estradiol to water-soluble products by a uterine preparation in the presence of hydrogen peroxide has been investigated. The addition of this phenol to a solution of uterine or horseradish peroxidase in 8 M urea restored the activity of the enzyme and also that of horseradish peroxidase inactivated by heating. It also protected the enzyme from inactivation during incubation. It is proposed that 2,4-dichlorophenol exerts its effect by activating peroxidase and protecting the enzyme from inactivation by the products of the reaction.