B. Isolation, purification, characterization, and assay of antioxygenic enzymes[13] Catalase in vitro
Publisher Summary
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.
References (20)
- D.P. Nelson et al.
Anal. Biochem.
(1972) - G. Cohen et al.
Anal. Biochem.
(1970) - L.A. Del Rio
Anal. Biochem.
(1977) - A. Rigo et al.
Anal. Biochem.
(1977) - B. Chance
Acta Chem. Scand.
(1947) - R.K. Bonnichsen et al.
Acta Chem. Scand.
(1947) - R. K. Bonnichsen, this series, Vol. II, p....
- B. Chance et al.
Physiol. Rev.
(1979) - H. Aebi
- H. Aebi et al.
Cited by (20808)
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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 effect of Argania spinosa seed oil on diabetic nephropathy in streptozotocin-induced diabetes in Wistar rats
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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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Both oils ameliorated significantly diabetic nephropathy symptoms. They limited the renal damage caused by streptozotocin and improved diabetes symptoms, including blood glucose levels, body weight, water intake, urinary volume, and kidney parameters. This activity could be elucidated by the antioxidant effect of Argan oil, enabling to neutralize free radicals and undertake a fundamental role in preventing the onset of these complications.
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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A total of 84 active ingredients and 830 target genes were screened in BYHWD, among which 56 target genes intersected with DPF-related targets. Network pharmacological analysis revealed that the active ingredients can regulate target genes such as IL-6, TNF-α, VEGFA and CASP3, mainly through AGE-RAGE signaling pathway, HIF-1 signaling pathway and TNF signaling pathway. Molecular docking and molecular dynamics simulations suggested that IL6-astragaloside IV, IL6-baicalein, TNFα-astragaloside IV, and TNFα-baicalein docking complexes could bind stably. Animal experiments showed that BYHWD could reduce the expression of core targets such as VEGFA, CASP3, IL-6 and TNF-α. In addition, BYHWD could reduce blood glucose, lipid, and MDA levels in DPF while increasing the activities of SOD, CAT and GSH-Px. BYHWD attenuated the expression of HYP and collagen I, mitigating pathological damage and collagen deposition within lung tissue.
BYHWD modulates lipid metabolism disorders and oxidative stress by targeting the core targets of IL6, TNF-α, VEGFA and CASP3 through the AGE-RAGE signaling pathway, making it a potential therapy for DPF.
Exogenous application of gibberellic acid reduces antioxidant capacity of leaves, resulting in increased Tipburn damages in Lisianthus cultivars
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