Immobilization of Recombinant Human Catalase on Gold and Silver Nanoparticles

Silicon dioxide nanoparticles adsorption alters the secondary and tertiary structures of catalase and undermines its activity

The expanding production and use of nanomaterials in various fields caused big concern for human health. Oxidative stress is the most frequently described mechanism of nanomaterial toxicity. A state of oxidative stress can be defined as the imbalance of reactive oxygen species (ROS) production and antioxidant enzyme activities. Although nanomaterials-triggered ROS generation has been extensively investigated, little is known regarding the regulation of antioxidant enzyme activities by nanomaterials. This study used two typical nanomaterials, SiO₂ nanoparticles (NPs) and TiO₂ NPs, to predict their binding affinities and interactions with antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). The molecular docking results showed that CAT and SOD had different binding sites, binding affinity, and interaction modes with SiO₂ NPs and TiO₂ NPs. The binding affinities of the two NPs to CAT were more potent than those to SOD. Consistently, the experimental work indicated NPs adsorption caused the perturbation of the second and tertiary structures of both enzymes and thus resulted in the loss of enzyme activities.

Biodegradation of environmental pollutants using catalase-based biocatalytic systems

The synergistic combination of biocatalysts and nanomaterials provides a new interface of a robust biocatalytic system that can effectively remediate environmental pollutants. Enzymes, such as catalase-based constructs, impart the desired candidature for catalytic transformation processes and are potential alternatives to replace conventional remediation strategies that have become laborious and somewhat inefficient. Furthermore, the controlled or uncontrolled discharge of various emerging pollutants (EPs) into water bodies is equally proportional to the fast-growing population and extensive urbanization. EPs affect the entire living being and continuously deteriorate the environmental system, directly or indirectly. The occurrence of EPs (even released after partial treatments, but still in bioactive forms) disturbs ecological integrity. Due to the ineffectiveness of in-practice traditional remediation processes, new and robust treatment measures as effective and sustainable remediation have become a meaningful goal. In this context, special attention has been shifted to engineering an enzyme (catalase)-based biodegradation system with immense prospects in environmental cleanup. The unique synergistic combination of nanomaterials (having multifunctional attributes) with enzymes of interest makes them a state-of-the-art interface that can further ameliorate bio-catalysis and biodegradation performance. This review covers current research and scientific advancement in developing and deploying catalase-based biocatalytic systems to mitigate several EPs from the environment matrices. The biocatalytic features of catalase, along with the mechanistic insight into H₂O₂ neutralization, several nano-based materials loaded with catalase, including nanoparticles (NPs), carbon nanotubes (CNTs), metal-organic frameworks (MOFs), polymeric-based composites, oxime-functionalized cryo-gel disks, electro-spun nanofibrous membranes, and other hybrid materials have also been discussed with suitable examples.

Thiolated hyaluronic acid and catalase-enhanced CD44-targeting and oxygen self-supplying nanoplatforms with photothermal/photodynamic effects against hypoxic breast cancer cells

Photothermal and photodynamic therapies (PTT/PDT) have been widely accepted as noninvasive therapeutic methods for cancer treatment. However, tumor hypoxia and insufficient delivery of photoactive compounds to cancer cells can reduce the efficacy of phototherapy. Herein, we first synthesized thiolated hyaluronic acid (THA) and then conjugated it with catalase (CAT) onto chlorin e6 (Ce6)-adsorbed small gold nanorods (Ce6@sAuNRs) with near-infrared (NIR)/visible light activated photothermal/photodynamic effects. The conjugation of THA and CAT on Ce6@sAuNRs resulted in a red-shift of the longitudinal LSPR absorption band of sAuNRs up to 1000 nm and maintained the excellent enzymatic activity of catalase. Modification of Ce6@sAuNRs with THA resulted in efficient internalization of the nanocomposite into MCF-7/ADR multidrug-resistant (MDR) breast cancer cells (CD44+), thereby significantly enhancing the intracellular accumulation of the photosensitizer Ce6. CAT endows Ce6@sAuNRs with self-supporting oxygen production, which enables them to efficiently generate singlet oxygen (¹O₂) under 660 nm laser irradiation and enhances the photodynamic effect against hypoxic breast cancer cells. The results highlight the prospect of this novel multi-functional nanoplatform integrating active biological macromolecules (THA and CAT) into photosensitizer/photothermal gold nanocomposites in overcoming the limitations of hypoxic MDR breast cancer cell treatment.

Recent Advances in Reactive Oxygen Species (ROS)-Responsive Polyfunctional Nanosystems 3.0 for the Treatment of Osteoarthritis

Osteoarthritis (OA) is an inflammatory and degenerative joint disease with severe effects on individuals, society, and the economy that affects millions of elderly people around the world. To date, there are no effective treatments for OA; however, there are some treatments that slow or prevent its progression. Polyfunctional nanosystems have many advantages, such as controlled release, targeted therapy and high loading rate, and have been widely used in OA treatment. Previous mechanistic studies have revealed that inflammation and ROS are interrelated, and a large number of studies have demonstrated that ROS play an important role in different types of OA development. In this review article, we summarize third-generation ROS-sensitive nanomaterials that scavenge excessive ROS from chondrocytes and osteoclasts in vivo. We only focus on polymer-based nanoparticles (NPs) and do not review the effects of drug-loaded or heavy metal NPs. Mounting evidence suggests that polyfunctional nanosystems will be a promising therapeutic strategy in OA therapy due to their unique characteristics of being sensitive to changes in the internal environment.

Effect of Silver Nanoparticles on the In Vitro Regeneration, Biochemical, Genetic, and Phenotype Variation in Adventitious Shoots Produced from Leaf Explants in Chrysanthemum

Novel and unique properties of nanomaterials, which are not apparent in larger-size forms of the same material, encourage the undertaking of studies exploring the multifaced effects of nanomaterials on plants. The results of such studies are not only scientifically relevant but, additionally, can be implemented to plant production and/or breeding. This study aimed to verify the applicability of silver nanoparticles (AgNPs) as a mutagen in chrysanthemum breeding. Chrysanthemum × grandiflorum (Ramat.) Kitam. ‘Lilac Wonder’ and ‘Richmond’ leaf explants were cultured on the modified MS medium supplemented with 0.6 mg·L⁻¹ 6-benzylaminopurine (BAP) and 2 mg·L⁻¹ indole-3-acetic acid (IAA) and treated with AgNPs (spherical; 20 nm in diameter size; 0, 50, and 100 mg·L⁻¹). AgNPs strongly suppressed the capability of leaf explants to form adventitious shoots and the efficiency of shoot regeneration. The content of primary and secondary metabolites (chlorophyll a, chlorophyll b, total chlorophylls, carotenoids, anthocyanins, phenolic compounds) and the activity of enzymatic antioxidants (superoxide dismutase and guaiacol peroxide) in leaf explants varied depending on the AgNPs treatment and age of culture. Phenotype variations of ex vitro cultivated chrysanthemums, covering the color and pigment content in the inflorescence, were detected in one 50 mg·L⁻¹ AgNPs-derived and five 100 mg·L⁻¹ AgNPs-derived ‘Lilac Wonder’ plants and were manifested as the color change from pink to burgundy-gold. However, no changes in inflorescence color/shape were found among AgNPs-treated ‘Richmond’ chrysanthemums. On the other hand, the stem height, number of leaves, and chlorophyll content in leaves varied depending on the AgNPs treatment and the cultivar analyzed. A significant effect of AgNPs on the genetic variation occurrence was found. A nearly two-fold higher share of polymorphic products, in both cultivars studied, was generated by RAPD markers than by SCoTs. To conclude, protocols using leaf explant treatment with AgNPs can be used as a novel breeding technique in chrysanthemum. However, the individual cultivars may differ in biochemical response, the efficiency of in vitro regeneration, genetic variation, and frequency of induced mutations in flowering plants.

Antioxidant enzymes immobilized on gold and silver nanoparticles enhance DNA repairing systems of rat skin after exposure to ultraviolet radiation

The aim of the study was to investigate in vivo whether the application of immobilized superoxide dismutase (SOD) and catalase (CAT) could enhance DNA repairing systems and reduce level of CPD (cyclobutane pyrimidine dimers) and 6-4PP ((6-4) pyrimidine-pyrimidone photoproducts), and whether the immobilization on gold (AuNPs) and silver (AgNPs) nanoparticles affects the outcome. The study presents secondary analysis of our previous research. Three-day application of SOD and CAT in all forms of solution decreased the levels of CPD and 6-4PP boosted by UV irradiation. The mRNA expression level of the nucleotide excision repair (NER) system genes (XPA, XPC, ERCC1, ERCC2, ERCC3, LIG1) increased after application of immobilized and free enzymes. Increased by UV irradiation, p53 mRNA expression level normalized with the enzyme application. In conclusion, application of free and immobilized antioxidant enzymes accelerates removal of harmful effects of UV radiation in the rat skin by increasing expression level of NER genes.

Immobilization of catalase on functionalized magnetic nanoparticles: a statistical approach

Magnetic nanoparticles (MNPs) Fe₃O₄, by virtue of easily modifiable surface, high surface-to-mass ratio and super-paramagnetic properties, are one of suitable candidates for the enzyme immobilization. Optimization of five important variables viz. concentration of 3-aminopropyl-tri-ethoxy-silane (APTES), glutaraldehyde (GA) and enzyme, time and temperature of loading was carried out using central composite type of experimental design without blocks giving 50 experiments including eight replicates at the central point. Characterization, stability and reusability studies were also carried out with optimized preparation. Results established the correlation between observed and response surface method (RSM) equation envisaged value (R ² 0.99, 0.97 and 0.98 for enzyme's activity, its loading over MNPs and corresponding specific activity, respectively. The predicted values suggested by RSM equation were 64.00 mM of APTES, 10.97 µL of GA, 14.50 mg mL^-1 of enzyme for 67 min at 22.6 °C, resulted in activity 32.1 U mg^-1 MNPs, while specific activity was 97.7 U mg^-1. Transmission electron microscopy (TEM) showed the sizes of MNPs (10.5 ± 1.7 nm), APTES-MNPs (10.23 ± 1.74 nm), GA-APTES-MNPs (11.84 ± 1.49 nm) and Catalase-GA-APTES-MNPs (13.32 ± 2.74 nm) were statistically similar. The enzyme MNPs preparation retained 81.65% activity after 144 h at 4 °C (free enzyme retained 7.87%) and 64.34% activity after 20 reuse cycles. Statistical optimized MNPs-based catalase preparation with high activity and magnetic strength was stable and can be used for further studies related to its application as analytical recyclable enzyme or magnetically oriented delivery in the body.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03173-8.

Silver Nanoparticles Effects on In Vitro Germination, Growth, and Biochemical Activity of Tomato, Radish, and Kale Seedlings

The interactions between nanoparticles and plant cells are still not sufficiently understood, and studies related to this subject are of scientific and practical importance. Silver nanoparticles (AgNPs) are one of the most commonly produced and used nanomaterials. This study aimed to investigate the influence of AgNPs applied at the concentrations of 0, 50, and 100 mg·L⁻¹ during the process of in vitro germination as well as the biometric and biochemical parameters of developed seedlings in three vegetable species: Solanum lycopersicum L. ‘Poranek’, Raphanus sativus L. var. sativus ‘Ramona’, and Brassica oleracea var. sabellica ‘Nero di Toscana’. The application of AgNPs did not affect the germination efficiency; however, diverse results were reported for the growth and biochemical activity of the seedlings, depending on the species tested and the AgNPs concentration. Tomato seedlings treated with nanoparticles, particularly at 100 mg·L⁻¹, had shorter shoots with lower fresh and dry weights and produced roots with lower fresh weight. Simultaneously, at the biochemical level, a decrease in the content of chlorophylls and carotenoids and an increase in the anthocyanins content and guaiacol peroxidase (GPOX) activity were reported. AgNPs-treated radish plants had shorter shoots of higher fresh and dry weight and longer roots with lower fresh weight. Treatment with 50 mg·L⁻¹ and 100 mg·L⁻¹ resulted in the highest and lowest accumulation of chlorophylls and carotenoids in the leaves, respectively; however, seedlings treated with 100 mg·L⁻¹ produced less anthocyanins and polyphenols and exhibited lower GPOX activity. In kale, AgNPs-derived seedlings had a lower content of chlorophylls, carotenoids, and anthocyanins but higher GPOX activity of and were characterized by higher fresh and dry shoot weights and higher heterogeneous biometric parameters of the roots. The results of these experiments may be of great significance for broadening the scope of knowledge on the influence of AgNPs on plant cells and the micropropagation of the vegetable species. Future studies should be aimed at testing lower or even higher concentrations of AgNPs and other NPs and to evaluate the genetic stability of NPs-treated vegetable crops and their yielding efficiency.

Simple kinetic method for assessing catalase activity in biological samples

A novel kinetic method for measuring catalase activity in biological samples was evaluated. The principle of the current method is based on the oxidation effect of unreacted hydrogen peroxide (H₂O₂) on pyrogallol red (PGR) using the catalytic effects of molybdenum. The decrease in the absorbance of PGR in the presence of H₂O₂ with time from 0.5 to 4.5 min was directly proportional to the concentration of H₂O₂, and, in turn, directly proportional to catalase activity. Erythrocyte lysate homogenates were used to measure catalase activity and the results of the current method were significantly correlated to those of the ammonium peroxovanadate method. The 3.1% within run and 4.7% between run coefficients of variation indicated the high precision of the present novel method. The validation process confirmed that the diagnostic method is appropriate for different types of biological samples. Here, we describe a rapid, relatively easy, and reliable method for measuring catalase activity. The assay could be applied as a diagnostic tool and is suitable in research contexts.•

A novel kinetic method for measuring catalase activity in biological samples was evaluated.

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The validation process confirmed that the diagnostic method is appropriate for different types of biological samples.

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The assay could be applied as a diagnostic tool and is suitable in research contexts.

Facile synthesis of catalase@ZIF-8 composite by biomimetic mineralization for efficient biocatalysis

Enzymes immobilized in metal-organic frameworks (MOFs) have attracted great attention as a promising hybrid material. In the study, a novel biomimetic mineralization encapsulation process for a highly stable and easily reusable catalase (CAT)@ZIF-8 composite has been designed. This immobilization process provides a high enzyme loading of 70 wt %. The CAT@ZIF-8 composites exhibited a much lower K_m value and better enzyme activity than those of free CAT, exhibiting good stability against enzymatic hydrolysis and protein denaturation under harsh conditions. The inhibitory effects of pesticides such as pH, temperature, solvent (i.e., methanol, dimethyl sulfoxide and tetrahydrofuran) and storage at room temperature (6 months) on the activity of free and immobilized catalase enzyme were investigated. The CAT@MOF composites also exhibited excellent reusability, an obvious advantage for treating a wastewater from food processing. The CAT@MOF developed is promising for the efficient removal of H₂O₂ under harsh conditions.

The effect of immobilized antioxidant enzymes on the oxidative stress in UV-irradiated rat skin

Aim: Superoxide dismutase (SOD) and catalase (CAT) immobilized on gold nanoparticles (AuNP) and silver nanoparticles (AgNP) nanoparticles were used to reduce UV radiation-induced oxidative stress in rat skin. Materials & methods: The antioxidant influence of the enzymes was investigated on level of malondialdehyde, 8-hydroksy-2'deoksyguanozine, myeloperoxidase, total antioxidant capacity, SOD2 and CAT activity and expression, and glutathione and glutathione peroxidase activity. Results: The application of immobilized SOD and CAT on UV-irradiated skin reduced malondialdehyde and 8-hydroksy-2'deoksyguanozine levels also SOD and CAT activity and expression increased. The tested enzymes influence glutathione peroxidase activity and level of total antioxidant capacity and glutathione. Conclusion: Immobilized enzymes increased the antioxidative potential of skin following UV irradiation.

The Role of microRNAs in Metabolic Syndrome-Related Oxidative Stress

Oxidative stress (OxS) is the cause and the consequence of metabolic syndrome (MetS), the incidence and economic burden of which is increasing each year. OxS triggers the dysregulation of signaling pathways associated with metabolism and epigenetics, including microRNAs, which are biomarkers of metabolic disorders. In this review, we aimed to summarize the current knowledge regarding the interplay between microRNAs and OxS in MetS and its components. We searched PubMed and Google Scholar to summarize the most relevant studies. Collected data suggested that different sources of OxS (e.g., hyperglycemia, insulin resistance (IR), hyperlipidemia, obesity, proinflammatory cytokines) change the expression of numerous microRNAs in organs involved in the regulation of glucose and lipid metabolism and endothelium. Dysregulated microRNAs either directly or indirectly affect the expression and/or activity of molecules of antioxidative signaling pathways (SIRT1, FOXOs, Keap1/Nrf2) along with effector enzymes (e.g., GPx-1, SOD1/2, HO-1), ROS producers (e.g., NOX4/5), as well as genes of numerous signaling pathways connected with inflammation, insulin sensitivity, and lipid metabolism, thus promoting the progression of metabolic imbalance. MicroRNAs appear to be important epigenetic modifiers in managing the delicate redox balance, mediating either pro- or antioxidant biological impacts. Summarizing, microRNAs may be promising therapeutic targets in ameliorating the repercussions of OxS in MetS.

Thermodynamics and kinetics of thermal deactivation of catalase Aspergillus niger

The thermal stability of enzyme-based biosensors is crucial in economic feasibility. In this study, thermal deactivation profiles of catalase Aspergillus niger were obtained at different temperatures in the range of 35°C to 70°C. It has been shown that the thermal deactivation of catalase Aspergillus niger follows the first-order model. The half-life time t 1/2 of catalase Aspergillus niger at pH 7.0 and the temperature of 35°C and 70°C were 197 h and 1.3 h respectively. Additionally, t 1/2 of catalase Aspergillus niger at the temperature of 5°C was calculated 58 months. Thermodynamic parameters the change in enthalpy ΔH*, the change in entropy ΔS* and the change Gibbs free energy ΔG* for the deactivation of catalase at different temperatures in the range of 35°C to 70°C were estimated. Catalase Aspergillus niger is predisposed to be used in biosensors by thermodynamics parameters obtained.

Synthesis, Structure, and Anticancer Activity of Symmetrical and Non-symmetrical Silver(I)-N-Heterocyclic Carbene Complexes

Synthesis and anticancer studies of three symmetrically and non-symmetrically substituted silver(I)-N-Heterocyclic carbene complexes of type [(NHC)₂-Ag]PF₆ (7-9) and their respective (ligands) benzimidazolium salts (4-6) are described herein. Compound 5 and Ag-NHC-complex 7 were characterized by the single crystal X-ray diffraction technique. Structural studies for 7 showed that the silver(I) center has linear C-Ag-C coordination geometry (180.00(10)^o). Other azolium and Ag-NHC analogues were confirmed by H¹ and C¹³-NMR spectroscopy. The synthesized analogues were biologically characterized for in vitro anticancer activity against three cancer cell lines including human colorectal cancer (HCT 116), breast cancer (MCF-7), and erythromyeloblastoid leukemia (K-562) cell lines and in terms of in vivo acute oral toxicity (IAOT) in view of agility and body weight of female rats. In vitro anticancer activity showed the values of IC₅₀ in range 0.31-17.9 μM in case of K-562 and HCT-116 cancer cell lines and 15.1-35.2 μM in case of MCF-7 while taking commercially known anticancer agents 5-fluorouracil, tamoxifen, and betulinic acid which have IC₅₀ values 5.2, 5.5, and 17.0 μM, respectively. In vivo study revealed vigor and agility of all test animals which explores the biocompatibility and non-toxicity of the test analogues.

Facile synthesis of SnO2shell followed by microwave treatment for high environmental stability of Ag nanoparticles

This study describes a new method for passivating Ag nanoparticles (AgNPs) with SnO₂ layer and their further treatment by microwave irradiation. The one-step process of SnO₂ layer formation was carried out by adding sodium stannate to the boiling aqueous AgNPs solution, which resulted in the formation of core@shell Ag@SnO₂ nanoparticles. The coating formation was a tunable process, making it possible to obtain an SnO₂ layer thickness in the range from 2 to 13 nm. The morphology, size, zeta-potential, and optical properties of the Ag@SnO₂NPs were studied. The microwave irradiation significantly improved the environmental resistance of Ag@SnO₂NPs, which remained stable in different biological solutions such as NaCl at 150 mM and 0.1 M, Tris-buffered saline buffer at 0.1 M, and phosphate buffer at pH 5.6, 7.0, and 8.0. Ag@SnO₂NPs after microwave irradiation were also stable at biologically relevant pH values, both highly acidic (1.4) and alkaline (13.2). Moreover, AgNPs covered with a 13 nm-thick SnO₂ layer were resistant to cyanide up to 0.1 wt%. The microwave-treated SnO₂ shell can facilitate the introduction of AgNPs in various solutions and extend their potential application in biological environments by protecting the metal nanostructures from dissolution and aggregation.

This study describes a new method for passivating Ag nanoparticles (AgNPs) with SnO₂ layer and their further treatment by microwave irradiation.

Amidrazone modified acrylic fabric activated with cyanuric chloride: A novel and efficient support for horseradish peroxidase immobilization and phenol removal

In this study, hydrazine treated acrylic fabrics (polyacrylonitrile, PAN) activated with cyanuric chloride was developed as supporting material for horseradish peroxidase (HRP) immobilization. The immobilization of HRP onto the modified supporting material was achieved after being end-over-end incubated for 12 h. Field emission scanning electron microscopy and Fourier-transform infrared spectroscopy techniques were used to confirm the successful immobilization. Reusability experiment was performed to estimate the ability of the immobilized HRP to recover the reaction medium, in which it was observed to retain 78% of its original activity after 10 cycles. Relative to the soluble HRP, the optimum pH and temperature for the immobilized HRP were shifted to 7-7.5 and 50 °C, respectively. The kinetic parameters of guaiacol and H₂O₂ for the immobilized HRP were determined to be Km/Vmax = 57.61, 11.35 and Kcat/Km = 1.87, 1.86, respectively, while the values for the free form were Km/Vmax = 41.49, 6.23 and Kcat/Km = 1.87, 1.86, respectively. Compared to the soluble form, the immobilized HRP exhibited higher resistance toward metal ions and some organic solvents. For an application perspective. The immobilization of HRP using this procedure has the potential to be used for industrial application and wastewater treatment.

A Study of the Activity of Recombinant Mn-Superoxide Dismutase in the Presence of Gold and Silver Nanoparticles

Superoxide dismutase (SOD) is one of the best characterized enzyme maintaining the redox state in the cell. A bacterial expression system was used to produce human recombinant manganese SOD with a His-tag on the C-end of the protein for better purification. In addition, gold and silver nanoparticles were chemically synthesized in a variety of sizes, and then mixed with the enzyme for immobilization. Analysis by dynamic light scattering and scanning transmission electron microscopy revealed no aggregates or agglomerates of the obtained colloids. After immobilization of the protein on AuNPs and AgNPs, the conjugates were analyzed by SDS-PAGE. It was determined that SOD was adsorbed only on the gold nanoparticles. Enzyme activity was analyzed in colloids of the gold and silver nanoparticles bearing SOD. The presence of a nanoparticle did not affect enzyme activity; however, the amount of protein and size of the gold nanoparticle did influence the enzymatic activity of the conjugate. Our findings confirm that active recombinant human superoxide dismutase can be produced using a bacterial expression system, and that the enzyme can be immobilized on metal nanoparticles. The interaction between enzymes and metal nanoparticles requires further investigation.