Hydrogen peroxide (H2O2) has been implicated in many stress conditions. Control of H2O2 levels is complex and dissection of mechanisms generating and relieving H2O2 stress is difficult, particularly in intact plants. We have used transgenic tobacco with approximately 10% wild-type catalase activity to study the role of catalase and effects of H2O2 stress in plants. Catalase-deficient plants sho...

Male NMRI mice were fed a diet with 10% w/w Beromegan for up to three weeks. Beromegan is a commercial fish (salmon) oil preparation rich in eicosapentaenoic acid and docosahexaenoic acid. Peroxisomal beta-oxidation capacity, catalase activity, and ultrastructural morphometry of the hepatic peroxisomes were investigated. In myocardium and kidney, catalase activity, peroxisomal staining after ca...

Catalase activity and stability in the presence of simple micelles of Brij 35 and entrapped in reverse micelles of Brij 30 have been studied. The enzyme retains full activity in aqueous micellar solution of Brij 35. Catalase exhibits "superactivity" in reverse micelles composed of 0.1 M Brij 30 in dodecane, n-heptane or isooctane, and significantly lowers the activity in decaline. The incorpora...

Peroxidatic activity of catalase (E .C .1 .11 .1 .6) was discovered by Keilin and Hartree (1), and it has been firmly established that, catalase oxidizes various substrates such as ethanol, methanol, nitrite, and formate (2-4) . Crystalline beef liver catalase, used as an enzyme tracer (5), and the peroxisomal catalase (6, 7) have been visualized cytochemically by a modification of the 3,3'diam...

In this study, an assay that combines the ease and simplicity of the qualitative approach for measuring catalase activity was developed. The assay reagents comprised only hydrogen peroxide and Triton X-100. The enzyme-generated oxygen bubbles trapped by Triton X-100 were visualized as foam, whose height was estimated. A calibration plot using the defined unit of catalase activity yielded the be...

Seasonal changes in antioxidant enzymes activities, amount of water, ash, proline and soluble sugars were surveyed during this research in four halophyte species of Varamin County, Tehran, Iran: Salsola turcomanica Litwin, Suaeda arcuata Bunge, Tamarix leptopetala Bunge and Cressa cretica L. Plants were collected randomly from their natural habitats in spring and summer. Activity of these enzym...

A new bromoperoxidase-catalase was purified from the chloramphenicol-producing actinomycete Streptomyces venezuelae ISP 5230. The homogeneous enzyme showed brominating activity, catalase activity and a very low peroxidase activity. The spectral properties and pH dependence of the catalase activity showed similarities to conventional catalases. In contrast to other haem-bromoperoxidases, the bro...

       Osteoporosis is a disease of high prevalence with increased bone loss. It has potential public health threat and that the health authorities had taken several measures for its control. In recent years, considerable attention has been given to physiopathology of osteoporosis. Oxidative stress has been proved to be involved in bone resorption. Oxidative stress occurs when balance between o...