B. Isolation, purification, characterization, and assay of antioxygenic enzymes[13] Catalase in vitro
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Catalase exerts a dual function: (1) decomposition of H2O2 to give H2O and O2 (catalytic activity) and (2) oxidation of H donors, for example, methanol, ethanol, formic acid, phenols, with the consumption of 1 mol of peroxide (peroxide activity). The kinetics of catalase does not obey the normal pattern. Measurements of enzyme activity at substrate saturation or determination of the Ks is therefore impossible. In contrast to reactions proceeding at substrate saturation, the enzymic decomposition of H2O2 is a first-order reaction, the rate of which is always proportional to the peroxide concentration present. Consequently, to avoid a rapid decrease in the initial rate of the reaction, the assay must be carried out with relatively low concentrations of H2O2 (about 0.01 M). This chapter discusses the catalytic activity of catalase. The method of choice for biological material, however, is ultraviolet (UV) spectrophotometry. Titrimetric methods are suitable for comparative studies. For large series of measurements, there are either simple screening tests, which give a quick indication of the approximative catalase activity, or automated methods.
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Aurothioglucose encapsulated nanoparticles fostered neuroprotection in streptozotocin-induced Alzheimer's disease
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Impairment on fillet fatty acid profile and oxidative damage in pirarucu, Arapaima gigas, acutely exposed to extreme ambient temperature
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The objective of our work is based on the evaluation of the effect of roasted (Roil) and unroasted (UnRoil) Argan seed oil on diabetic nephropathy.
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Based on our findings, Argan oil could be used as dietary supplement for people with diabetes as a preventive measure against the emergence of diabetic complications.
Deciphering the molecular mechanism of Bu Yang Huan Wu Decoction in interference with diabetic pulmonary fibrosis via regulating oxidative stress and lipid metabolism disorder
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Exogenous application of gibberellic acid reduces antioxidant capacity of leaves, resulting in increased Tipburn damages in Lisianthus cultivars
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