Partial Purification of Estrogen-Dependent Peroxidase of Rat Uterus and Comparison of the Properties with Those of Other Animal Peroxidases

Abstract

An attempt was made to solubilize a peroxidase from the uterine tissue of estrogenprimed rats using various detergents, and the best result was obtained by incubation with 4% cetyltrimethylammonium bromide at 37°C for 60min. The solubilized material was then dialyzed and subjected to gel filtration on Sephacryl S-200 followed by CM-cellulose chromatography, resulting in a 50-250-fold increase in specific activity over the detergent extract. Some properties of the partially purified uterine tissue peroxidase were studied in comparison with those of other animal peroxidases. The absorption spectra, molecular weight, and isoelectric point are very similar to those of lactoperoxidase. However, the oxidation rates of various hydrogen donor substrates by the uterine peroxidase were not parallel to those of lactoperoxidase and other animal peroxidases and the affinities for cyanide and azide of these enzymes were somewhat different from each other. The uterine peroxidase was inhibited by histidine and excess hydrogen peroxide competitively with respect to guaiacol, suggesting an important role of an amino acid residue in the protein moiety.