Methoxypolyethylene glycols of 1900 daltons (PEG-1900) or 5000 daltons (PEG-5000) were covalently attached to bovine liver catalase using 2,4,6-trichloro-s-triazine as the coupling agent. Rabbits were immunized by the intravenous and intramuscular routes with catalase modified by covalent attachment of PEG-1900 to 43% of the amino groups (PEG-1900-catalase). The intravenous antiserum did not yi...

Since oxygen-free polymorphonuclear neutrophils (PMN) cannot kill Staphylococcus aureus normally, the usual mechanisms for PMN bactericidal activity probably involve hydrogen peroxide or superoxide. Catalase can destroy hydrogen peroxide, and superoxide dismutase breaks down superoxide. Experiments were performed to study the influence of these enzymes (which are found in staphylococci) on viru...

Brahn (3) observed very low liver catalase ac tivity in human beings who had died as the result of malignant growths. Later work showed that of all the individual liver enzymes studied in can cerous rats and mice the activity of catalase was by far the most affected. Greenstein and co workers (6, 7) have reported that with the pro gressive growth of the tumor there is a decrease in liver catala...

Injection of 3-amino-1,2,4-triazole into rats resulted in a rapid fall of liver catalase activity which gradually returned to the normal level, but the amount of catalase protein determined by the immunochemical method remained constant without any decrease in parallel with the enzyme activity. Inactivation occurred more rapidly with soluble catalase (or Catalase-II) than with catalase in perox...

Pyocyanin, produced by Pseudomonas aeruginosa, has many deleterious effects on human cells that relate to its ability to generate reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. Human cells possess several mechanisms to protect themselves from ROS, including manganese superoxide dismutase (MnSOD), copper zinc superoxide dismutase (CuZnSOD), and catalase. Given the link ...

Catalase (H2O2:H2O2 oxidoreductase, EC 1.11.1.6) is of historical interest for having been the subject of some of the earliest investigations of enzymes. A feature of catalase that has been poorly understood for several decades, however, is the mechanism by which catalase remains active in the presence of its own substrate, hydrogen peroxide. We reported recently that catalase contains tightly ...

Catalase was partially purified (about 380-fold purification) from the post-mitochondrial supernatant of bovine heart and compared with catalases from bovine erythrocytes and bovine liver. The electrophoretic mobility in polyacrylamide gel (pH 8.0) of heart catalase was the same as that of erythrocyte catalase and was smaller than that of the liver enzyme. The heart catalase was indistinguishab...

Catalase (H2O2:H2O2 oxidoreductase, E.C. 1.11.1.6) is a ubiquitous antioxidant metalloenzyme located primarily within the peroxisomes of most mammalian cells. In C57BL/6 mice, liver catalase activity levels are approximately 60% of the levels found in most other mouse strains, including C3H/HeJ (1). Ganschow and Schimke (2) demonstrated using immunological techniques that equal numbers of catal...

Catalase is an essential antioxidant enzyme that is well characterized from microbial and animal sources. The structure of plant catalase is unknown. Therefore, it is of interest to understand the functional and structural characteristics of catalase from an Indian gooseberry, Phyllanthus emblica (or Emblica officinalis). Hence, catalase from P. emblica was cloned in pUC18 plasmid, sequenced an...

The ability of the H2O2-induced catalase of Salmonella typhimurium to induce cell-mediated immunity against S. typhimurium infection in mice was examined. When exponentially growing cells of S. typhimurium were treated with 20 microM H2O2, the cells resisted killing by 1 mM H2O2 and showed the induction of a new species of catalase in addition to the constitutively produced one. Two molecules o...