Enzyme immobilization using metal-organic frameworks (MOFs) as carriers has aroused significant interest owing to the unique pore structure and versatile surface functional groups of MOFs. Catalase (CAT) is an important industrial enzyme that is widely used in the catalytic decomposition of hydrogen peroxide in the fields of food and biological products. In this study, mesoporous MIL-101 (Cr), synthesized through a facile hydrothermal process, was applied for CAT immobilization for the first time. The immobilization capacity of MIL-101 (Cr) for CAT was studied systematically by batch adsorption tests under different adsorption conditions, including the variation of the solution pH, operation temperature, adsorption time, and initial concentration of CAT. Based on these test findings, the optimum adsorption conditions and maximum adsorption capacity were determined.
The adsorption kinetics were simulated to further explore the adsorption mechanism, and they suggest that chemical adsorption, rather than physical adsorption, is the main CAT adsorption mechanism. A comparison of Fourier transform infrared (FT-IR) spectra of MIL-101 (Cr) without and with adsorbed CAT reveals the formation of amide bonding between the -NH of CAT and the uncoordinated -CO of MIL-101(Cr). Finally, the stability and activity of the immobilized CAT were assessed, and an improved insensitivity against changes in pH and a prolonged storage time demonstrate the enhanced stability of immobilized CAT by MIL-101 (Cr) carriers. This study demonstrates the application of MOFs as functional supports for the efficient immobilization of versatile enzymes.
Response of earthworm coelomocytes and catalase to pentanone and hexanone: a revelation of the toxicity of conventional solvents at the cellular and molecular level
Organic solvents like 2-pentanone and 2-hexanone which are widely used in industrial production make up a large proportion of the source of chemical pollution. What is worrisome is that the cellular and molecular toxicity of 2-pentanone and 2-hexanone has not been reported yet. Based on this, earthworms and catalase (CAT) were chosen as target receptors for the toxicity studies. The cytotoxicity of 2-pentanone and 2-hexanone was revealed by measuring the multiple intracellular indicators of oxidative stress. At the molecular level, changes in the structure and function of CAT were characterized in vitro by the spectroscopy and molecular docking.
The results show that 2-pentanone and 2-hexanone that induced the accumulation of reactive oxygen species can eventually reduce coelomocytes viability, accompanying by the regular changes of antioxidant activity and lipid peroxidation level. In addition, the exposure of 2-pentanone and 2-hexanone can shrink the backbone structure of CAT, quench the fluorescence, and misfold the secondary structure. The decrease in enzyme activity should be attributed to the structural changes induced by surface binding. This study discussed the toxicological effects and mechanisms of conventional solvents at the cellular and molecular level, which creatively proposed a joint research method.
Microglial Inflammation and Cognitive Dysfunction in Comorbid Rat Models of Striatal Ischemic Stroke and Alzheimer’s Disease: Effects of Antioxidant Catalase-SKL on Behavioral and Cellular Pathology
- Ischemic stroke often co-occurs with Alzheimer’s disease (AD) leading to a worsened clinical outcome. Neuroinflammation is a critical process implicated in AD and ischemic pathology, associated with cognitive decline. We sought to investigate the combined effects of ischemic stroke induced by endothelin-1 injection in two AD rat models, using motor function, memory and microglial inflammation in the basal forebrain and striatum as readouts. In addition, we sought to determine the effectiveness of the antioxidant biologic CAT-SKL in one of the models.
- The early AD model employed the bilateral intracerebroventricular injections of the toxic β-amyloid peptide Aβ25-35, the prodromal AD model used the transgenic Fischer 344 rat overexpressing a pathological mutant human amyloid precursor protein. Motor function was assessed using a cylinder, modified sticky tape and beam-walk tasks; learning and memory were tested in the Morris water maze. Microglial activation was examined using immunohistochemistry. Aβ25-35 toxicity and stroke combination greatly increased microglial inflammation in the basal forebrain. Prodromal AD-pathology coupled with ischemia in the transgenic rat resulted in a greater microgliosis in the striatum.
- Combined transgenic rats showed balance alterations, comorbid Aβ25-35 rats showed a transient sensorimotor deficit, and both demonstrated spatial reference memory deficit. CAT-SKL treatment ameliorated memory impairment and basal forebrain microgliosis in Aβ25-35 rats with stroke. Our results suggest that neuroinflammation could be one of the early processes underlying the interaction of AD with stroke and contributing to the cognitive impairment, and that therapies such as antioxidant CAT-SKL could be a potential therapeutic strategy.
Safety evaluation of the food enzyme catalase from porcine liver
The food enzyme catalase (EC 1.11.1.6) is obtained from porcine liver by Laboratorios Arroyo S.A. It is intended to be used in a broad range of food processes. The Panel noted that the manufacturing process involved the use of a solvent not permitted in the production of food ingredients which include food enzymes. In addition, the evidence provided showed that the manufacturing process could not be guaranteed to inactivate viruses originating from the starting material, including the human zoonotic pathogen Hepatitis E virus. Consequently, the Panel concluded that the use of catalase extracted from porcine liver may present a health risk.
The Role of H 2 O 2-Scavenging Enzymes (Ascorbate Peroxidase and Catalase) in the Tolerance of Lemna minor to Antibiotics: Implications for Phytoremediation
We investigated the individual and combined contributions of two distinct heme proteins namely, ascorbate peroxidase (APX) and catalase (CAT) on the tolerance of Lemna minor plants to antibiotics. For our investigation, we used specific inhibitors of these two H2O2-scavenging enzymes (p-aminophenol, 3-amino,1,2,4-triazole, and salicylic acid). APX activity was central for the tolerance of this aquatic plant to amoxicillin (AMX), whereas CAT activity was important for avoiding oxidative damage when exposed to ciprofloxacin (CIP).
Both monitored enzymes had important roles in the tolerance of Lemna minor to erythromycin (ERY). The use of molecular kinetic approaches to detect and increase APX and/or CAT scavenging activities could enhance tolerance, and, therefore, improve the use of L. minor plants to reclaim antibiotics from water bodies.
Catalase |
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| 20-abx082462 |
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| AP81185 | 1mg | 2640 EUR |
Catalase |
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| AP81334 | 1mg | 2640 EUR |
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| AP81344 | 1mg | 2640 EUR |
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| AP81469 | 1mg | 2640 EUR |
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| AP81472 | 1mg | 2640 EUR |
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| AP81772 | 1mg | 2640 EUR |
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| E8ER40125 | 100ul | 275 EUR |
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| E8ET1703-31 | 100ul | 275 EUR |
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| E8M1501-6 | 100ul | 275 EUR |
Catalase |
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| MBS5771872-100mg | 100mg | 145 EUR |
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| MBS5771872-200mg | 200mg | 160 EUR |
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| MBS5771872-500mg | 500mg | 215 EUR |
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| MBS5771872-5x500mg | 5x500mg | 815 EUR |
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| MBS8533601-01mL | 0.1mL | 345 EUR |
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| MBS8533601-01mLAF405L | 0.1mL(AF405L) | 565 EUR |
Catalase |
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| MBS8533601-01mLAF405S | 0.1mL(AF405S) | 565 EUR |
Catalase |
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| MBS8533601-01mLAF610 | 0.1mL(AF610) | 565 EUR |
Catalase |
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| MBS8533601-01mLAF635 | 0.1mL(AF635) | 565 EUR |
Catalase |
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| MBS8534434-01mL | 0.1mL | 345 EUR |
Catalase |
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| MBS8534434-01mLAF405L | 0.1mL(AF405L) | 565 EUR |
Catalase |
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| MBS8534434-01mLAF405S | 0.1mL(AF405S) | 565 EUR |
Catalase |
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| MBS8534434-01mLAF610 | 0.1mL(AF610) | 565 EUR |
Catalase |
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| MBS8534434-01mLAF635 | 0.1mL(AF635) | 565 EUR |
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| MBS8534591-01mL | 0.1mL | 345 EUR |
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| MBS8534591-01mLAF405L | 0.1mL(AF405L) | 565 EUR |
Theoretical and Experimental Considerations for a Rapid and High Throughput Measurement of Catalase In Vitro
A rapid and high throughput protocol to measure the catalase activity in vitro has been designed. Catalase is an enzyme with unusual kinetic properties because it does not follow the standard Michaelis-Menten model and is inactivated by H2O2. This makes the analysis of the two rate equations of the second-ordered reactions of the kinetic model rather complex. A two-degree polynomial fitting of the experimental data is proposed after transforming the exponential form of the integrated rate equation of the [H2O2] into a polynomial using the Taylor series.
The fitting is validated by establishing an experimental linear relationship between the initial rate of the H2O2 decomposition and the protein concentration, regardless of the suicide inactivation that catalase might undergo beyond t > 0. In addition, experimental considerations are taken into account to avoid statistical bias in the analysis of the catalase activity. ANOVA analyses show that the proposed protocol can be utilized to measure the initial rate of the H2O2 decomposition by catalase in 32 samples in triplicates if kept below 8 mM min-1 in the microplate wells. These kinetic and statistical analyses can pave the way for other antioxidant enzyme activity assays in microplate readers at small scale and low cost.