Unlike lactoperoxidase and horseradish peroxidase, thyroid peroxidase catalyzed the oxidation of hydroquinone mostly by way of 2-electron transfer. This conclusion could be derived from three independent experiments: ESR measurements of p-benzosemiquinone, trapping the unpaired electron by cytochrome c, and spectrophotometric analysis of catalytic intermediates of the enzymes. The 1-electron fl...

Data derived from a correlated morphological and biochemical study suggest the following: (a) estradiol-17beta, diethylstilbestrol, the estrogen antagonists nafoxidine (Upjohn 11,000), and Parke Davis C1628 induce synthesis of an endogenous peroxidase in the epithelium of target tissues like the vagina, the cervix, the uterus, and in the acinar cells of the estrogen-dependent rat mammary tumor;...

Ammonium sulfate fractionated proteins of bitter gourd (Momordica charantia) were precipitated using jack bean extract as a source of concanavalin A. Concanavalin A-bitter gourd peroxidase retained nearly 86% original activity. This complex was entrapped into calcium alginate-pectin gel. Entrapped concanavalin A-peroxidase complex retained 51% original activity. Soluble and immobilized peroxida...

When plants are threaten by microbial attacks or treated with elicitors, alkalization of extracellular space is often induced and thus pH-dependent extracellular peroxidase-mediated oxidative burst reportedly takes place, especially at the site of microbial challenge. However, direct stimulus involved in activation of peroxidase-catalyzed oxidative burst has not been identified to date. Here, w...

The upstream sequences of all published lignin peroxidase and manganese peroxidase genomic clones from Phanerochaete chrysosporium were analyzed. This analysis revealed the presence of putative activator protein-2 (AP-2) recognition sequences in 11 of 15 lignin peroxidase genes. The lignin peroxidase clone GLG6 and the manganese peroxidase gene (mnp-1) have two copies of putative AP-2 sequence ...

The absorption of macromolecules from the small intestine of rats was studied in terms of the amount of peroxidase activity that appeared in thoracic duct lymph after a 10 mg dose of horseradish peroxidase had been injected directly into the lumen of the duodenum. When the horseradish peroxidase was injected as a solution in saline no peroxidase activity was detected in the lymph. When ethyl al...

Recent studies in the field of autoimmune thyroid diseases have largely focused on the delineation of B-cell auto-epitopes recognized by the main autoantigens to improve our understanding of how these molecules are seen by the immune system. Among these autoantigens which are targeted by autoantibodies during the development of autoimmune thyroid diseases, thyroid peroxidase is a major player. ...

Inorganic pyrophosphatase, peroxidase, and polyphenoloxidase activities were studied as the function of leaf insertion level in eight monocotyledonous and eight dicotyledonous species. Alkaline inorganic pyrophosphatase shows a declining activity toward the end of senescence whereas no regular drift in either peroxidase or polyphenoloxidase activities was noticed during senescence of attached l...

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 ...

Horseradish peroxidase was administered to mice by intravenous injection, and its distribution in cerebral cortex studied with a recently available technique for localizing peroxidase with the electron microscope. Brains were fixed by either immersion or vascular perfusion 10-60 min after administration of various doses of peroxidase. Exogenous peroxidase was localized in the lumina of blood ve...