Flow injection catalase activity measurement based on gold nanoparticles/carbon nanotubes modified glassy carbon electrode

Catalase immobilization: Current knowledge, key insights, applications, and future prospects - A review

Catalase (CAT), a ubiquitous enzyme in all oxygen-exposed organisms, effectively decomposes hydrogen peroxide (H2O2), a harmful by-product, into water and oxygen, mitigating oxidative stress and cellular damage, safeguarding cellular organelles and tissues. Therefore, CAT plays a crucial role in maintaining cellular homeostasis and function. Owing to its pivotal role, CAT has garnered considerable interest. However, many challenges arise when used, especially in multiple practical processes. "Immobilization", a widely-used technique, can help improve enzyme properties. CAT immobilization offers numerous advantages, including enhanced stability, reusability, and facilitated downstream processing. This review presents a comprehensive overview of CAT immobilization. It starts with discussing various immobilization mechanisms, support materials, advantages, drawbacks, and factors influencing the performance of immobilized CAT. Moreover, the review explores the application of the immobilized CAT in various industries and its prospects, highlighting its essential role in diverse fields and stimulating further research and investigation. Furthermore, the review highlights some of the world's leading companies in the field of the CAT industry and their substantial potential for economic contribution. This review aims to serve as a discerning, comprehensive source of information for researchers seeking a comprehensive cutting-edge overview of this rapidly evolving field and have been overwhelmed by the size of publications.

A quantitative method for the detection and validation of catalase activity at physiological concentration in human serum, plasma and erythrocytes

A novel method has been proposed to develop a simple, rapid, sensitive and affordable chromogenic attempt for the quantification of catalase (CAT) activity in blood samples. The method is based on the oxidation of pyrocatechol (PC) to give quinone form which by oxidative coupling with aminyl radical of 4-aminoantipyrine (4-AAP) resulting from H₂O₂/CAT to produce a pink colored quinone-imine product with λ_max = 530 nm in a 100 mmol/L of tris buffer of pH 9.8 at room temperature (30 °C). The linearity of CAT assay was between 0.316 and 10 U/mL. The accuracy ranges for CAT having concentrations of 1.25, 5 and 7.5 μmol/L were 89-105.52, 90-107%, and 91-104.58% respectively. Within-run and between-run precision studies showed CV's of 1.98-3.02% (n = 7) and 2.97-4.40% (n = 7), respectively. The detection and quantification limits of CAT were 0.12 and 0.225 μmol/L, respectively. The Michaelis-Menten constant and maximum velocity of the reaction was K_m = 1.052 mM and V_max = 0.168 μmol/min, respectively. The present method provides a convenient means for investigating the usefulness of CAT measurements in biological sample assessing the potential for free radical-induced pathology.

Developments in support materials for immobilization of oxidoreductases: A comprehensive review

Bioremediation, a biologically mediated transformation or degradation of persistent chemicals into nonhazardous or less-hazardous substances, has been recognized as a key strategy to control levels of pollutants in water and soils. The use of enzymes, notably oxidoreductases such as laccases, tyrosinases, various oxygenases, aromatic dioxygenases, and different peroxidases (all of EC class 1) is receiving significant research attention in this regard. It should be stated that immobilization is emphasized as a powerful tool for enhancement of enzyme activity and stability as well as for protection of the enzyme proteins against negative effects of harsh reaction conditions. As proper selection of support materials for immobilization and their performance is overlooked when it comes to comparing performance of immobilized enzyme in academic studies, this review summarizes the current state of knowledge regarding the materials used for enzyme immobilization of these oxidoreductase enzymes for environmental applications. In the presented study, thorough physicochemical characteristics of the support materials was presented. Moreover, various types of reactions and notably operational modes of enzymatic processes for biodegradation of harmful pollutants are summarized, and future trends in use of immobilized oxidoreductases for environmental applications are discussed. Our goal is to provide an improved foundation on which new technological advancements can be made to achieve efficient enzyme-assisted bioremediation.

Direct measurement of catalase activity in living cells and tissue biopsies

Spatiotemporal regulation of enzyme-substrate interactions governs the decision-making steps in biological systems. Enzymes, being functional units of every living cell, contribute to the macromolecular stability of cell survival, proliferation and hence are vital windows to unraveling the biological complexity. Experimental measurements capturing this dynamics of enzyme-substrate interactions in real time add value to this understanding. Furthermore these measurements, upon validation in realistic biological specimens such as clinical biopsies - can further improve our capability in disease diagnostics and treatment monitoring. Towards this direction, we describe here a novel, high-sensitive measurement system for measuring diffusion-limited enzyme-substrate kinetics in real time. Using catalase (enzyme) and hydrogen peroxide (substrate) as the example pair, we demonstrate that this system is capable of direct measurement of catalase activity in vitro and the measured kinetics follows the classical Michaelis-Menten reaction kinetics. We further demonstrate the system performance by measuring catalase activity in living cells and in very small amounts of liver biopsies (down to 1 μg total protein). Catalase-specific enzyme activity is demonstrated by genetic and pharmacological tools. Finally we show the clinically-relevant diagnostic capability of our system by comparing the catalase activities in liver biopsies from young and old mouse (liver and serum) samples. We discuss the potential applicability of this system in clinical diagnostics as well as in intraoperative surgical settings.