An optimized coupled test system for glutathione peroxidase in red blood cells is presented. In the improved assay, tert. butyl hydroperoxide was employed as an acceptor substrate at twenty times Km(app) concentration. By aid of a batching procedure for instant separation of hemoglobin from glutathione peroxidase, it could be proved that cyanmethemoglobin in the modified procedure does not affe...

Recent studies have indicated that peroxidase might function in the biological synthesis of thyroxine by the thyroid gland. Johnson and Tewkesbury (1) believed that thyroxine might be formed by the oxidative coupling of 2 molecules of diiodotyrosine. Westerfeld and Lowe (2) studied the oxidative condensation of p-cresol by hydrogen peroxide and peroxidase and suggested that peroxidase might be ...

Recent studies have indicated that peroxidase might function in the biological synthesis of thyroxine by the thyroid gland. Johnson and Tewkesbury (1) believed that thyroxine might be formed by the oxidative coupling of 2 molecules of diiodotyrosine. Westerfeld and Lowe (2) studied the oxidative condensation of p-cresol by hydrogen peroxide and peroxidase and suggested that peroxidase might be ...

The influence of protein conformation upon the circular dichroism (CD) bands of two peroxidase isoenzymes (Al and C) was investigated by using guanidine hydrochloride and other denaturing agents. In all four proteins, guanidine hydrochloride markedly reduces the Zl-nm CD band, indicating disruption of the ordered peptide backbone conformation. Similarly guanidine hydrochloride greatly diminishe...

The endogenous peroxidase synthesis within the uterine epithelial cells during the neonatal period of female rats following the . estrogen stimulation was studied by means of the histochemical method, to elucidate the critical period in the initiation of its synthesis and the relation between the peroxidase synthesis and the morphological alteration within these cells. The critical period was a...

Tyrosine hydroxylase, dopa oxidase, and peroxidase activities were studied in soluble fractions of B16 melanoma tumor homogenates by polyacrylamide gel disc electrophoresis. Stained gels were scanned photometrically and gel slices were assayed radiometrically. In these preparations, the two bands of tyrosine hydroxylating activity were completely separated from the peroxidase activity but coinc...

Synthesis of peroxidase was induced in the uterine epithelium of immature rats by multiple doses over a 24-96-h period of either 17 beta-estradiol, the estrogen-antagonist Parke-Davis CI-628, or a combination of estradiol plus antagonist. Endogenous peroxidase activity first appeared in the cisternae of the rough endoplasmic reticulum of surface epithelial and glandular cells within 24-48 after...

Rotavirus infections in intestinal tissues of animals or in tissue culture cells were detected by the immunocytochemical unlabeled soluble enzyme peroxidase antiperoxidase method. Comparison of the immunofluorescence and peroxidase antiperoxidase immunological staining techniques revealed that the two methods are equally sensitive for detection of rotavirus-infected cells. The peroxidase antipe...