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Journal of Environmental Science and... 2020The combination of semiconductor and metal nanocomponents represents an effective way for design of photocatalysts with high efficiency. It is expected that this...
The combination of semiconductor and metal nanocomponents represents an effective way for design of photocatalysts with high efficiency. It is expected that this strategy can be applied to design photo-regulated nanozymes. To prove this concept, BiOBr/PtRu hybrid nanostructures have been fabricated by depositing PtRu nanoparticles on BiOBr nanosheets through a templating co-reduction method. The formation of BiOBr/PtRu hybrid nanostructures was confirmed by TEM, XRD and XPS. BiOBr/PtRu hybrid nanostructures exhibited excellent enzyme-like activities (peroxidase, oxidase, ferroxidase) as well as the ability to scavenge DPPH free radicals. When exposed to light irradiation ( > 420 nm), it was found that BiOBr/PtRu hybrid nanostructures not only exhibit improved photocatalytic degradation, but also exhibit enhanced peroxidase- and oxidase-like activity. Due to the photocatalytic effect and the higher charge separation and utilization efficiency caused by heterojunctions, a light-enhanced enzyme-like activity mechanism was proposed. These results will be of value to design high efficiency nanozymes using light for biological and environmental applications.
Topics: Bismuth; Catalysis; Light; Nanostructures; Peroxidase; Peroxidases; Photochemical Processes
PubMed: 33356923
DOI: 10.1080/26896583.2020.1814081 -
Colloids and Surfaces. B, Biointerfaces Aug 2021Nanozymes have significant advantages over natural enzymes. The intrinsic peroxidase-like activity of Pt-based nanomaterials can be enhanced by alloying with other...
Nanozymes have significant advantages over natural enzymes. The intrinsic peroxidase-like activity of Pt-based nanomaterials can be enhanced by alloying with other transition metals, such as Ru, that have great catalytic activity. In this study, we used polyvinylpyrrolidone (PVP) to synthesize well-dispersed and homogeneous nanostructures. PVP-stabilized Pt-Ru nanozymes (PVP/PtRu NZs) were synthesized and characterized. The PVP/PtRu NZs had an average size of 3.54 ± 0.84 nm and exhibited an intense peroxidase-like activity. The PVP/PtRu NZs were used as peroxidase mimics for colorimetric and fluorometric glucose determination by the glucose oxidase and PVP/PtRu NZs cascade reaction. In the colorimetric assay, the linearly detectable range was 0.25-3.0 mM, with an R and limit of detection (LOD) of 0.988 and 138 μM, respectively. In the fluorometric assay, a linear relationship was found when the glucose concentration was between 5.0 and 300 μM (R = 0.997), with an LOD of 1.11 μM. Compared to the colorimetric assay, the fluorometric assay had greater sensitivity and a lower detection limit for the determination of glucose. Moreover, the PVP/PtRu NZs had high storage stability over a month and great recovery values in human serum and artificial urine, with a range of 94-106 %. From these results, PVP/PtRu NZs are expected to be used as promising peroxidase mimics in various fields such as biosensing, pharmaceutical processing, and the food industry.
Topics: Biosensing Techniques; Colorimetry; Glucose; Glucose Oxidase; Humans; Hydrogen Peroxide; Peroxidase; Peroxidases; Povidone
PubMed: 33940519
DOI: 10.1016/j.colsurfb.2021.111783 -
Pharmacology & Therapeutics Feb 2021Heme peroxidases are a major source of reactive oxidants at sites of inflammation in biological systems. The formation of some of these oxidants (e.g. hypochlorous acid,... (Review)
Review
Heme peroxidases are a major source of reactive oxidants at sites of inflammation in biological systems. The formation of some of these oxidants (e.g. hypochlorous acid, HOCl) is important in the innate immune response of activated neutrophils and leukocytes to invading pathogens (e.g. bacteria, yeasts, fungi parasites), and responsible for the anti-microbial activity present in excreted fluids (e.g. hypothiocyanous acid, HOSCN, generated by lactoperoxidase). Other oxidants formed by heme peroxidase family members are important in tissue development (e.g. hypobromous acid, HOBr, formation by peroxidasin) and in the synthesis of thyroid hormones (hypoiodous acid, HOI, synthesized by thyroid peroxidase). However, inadvertent, misplaced or poorly-controlled production of these species can result in host tissue damage, and this underlies the strong association between high levels of some of these enzymes and multiple inflammatory pathologies. As a consequence, there is widespread interest in understanding the kinetics and mechanisms of biomolecule modification by these species, which differ dramatically in their actions, the nature of the products formed (as some of these are specific biomarkers of enzyme activity), and the biological consequences of these reactions in a wide range of diseases associated with acute or chronic inflammation. Increased knowledge of these processes, has allowed the development of a number of alternative and complementary strategies that allow modulation of oxidant formation and subsequent damage. This review discusses developments in these fields and the prospects for tailored inhibition of specific members of this enzyme family.
Topics: Humans; Inflammation; Peroxidase
PubMed: 32961264
DOI: 10.1016/j.pharmthera.2020.107685 -
Current Protein & Peptide Science 2022Laccases and peroxidases have attracted great interest for industrial and environmental applications. These enzymes have a broad substrate range and a robust oxidizing...
AIM
Laccases and peroxidases have attracted great interest for industrial and environmental applications. These enzymes have a broad substrate range and a robust oxidizing ability. Moreover, using mediators or co-oxidants makes it possible to increase their catalytic activity and extend their substrate scope to more resistant chemical structures.
BACKGROUND
Fungal laccases and ligninolytic peroxidases, mainly lignin and manganese peroxidases, are the privileged oxidoreductases for bioremediation processes. Nonetheless, an increasing diversity of laccases and peroxidase-type enzymes has been proposed for environmental technologies.
OBJECTIVE
This article aims to provide an overview of these enzymes and compare their applicability in the degradation of organic pollutants.
METHODS
Fundamental properties of the proteins are covered and applications towards polycyclic aromatic hydrocarbons (PAHs) and pesticides are specially focused.
RESULTS
Laccases are multicopper oxidases initially studied for applications in the pulp and paper industry but able to oxidize a variety of environmentally concerning compounds. Relying on O, laccases do not require peroxides nor auxiliary agents, like Mn, although suitable redox mediators are needed to attack the more recalcitrant pollutants (e.g., PAHs). True and pseudo-peroxidases use a stronger oxidant (HO) and the redox chemistry at the heme site generates high potential species that allow the oxidation of dyes and some pesticides.
CONCLUSION
Lately, research efforts have been directed to enzyme discovery, testing with micropollutants, and improving biocatalysts' stability by immobilization and protein engineering. Further understanding of the effects of natural media components and solvents on the enzymes might lead to competitive enzymatic treatments of highly toxic media.
Topics: Laccase; Biodegradation, Environmental; Lignin; Environmental Pollutants; Peroxidase; Hemeproteins; Hydrogen Peroxide; Manganese; Peroxidases; Oxidation-Reduction; Polycyclic Aromatic Hydrocarbons; Heme; Pesticides; Coloring Agents; Oxidants; Solvents
PubMed: 35794739
DOI: 10.2174/1389203723666220704090416 -
Enzyme and Microbial Technology Nov 2020The extracellular peroxidase from Streptomyces albidoflavus BSII#1 was purified to near homogeneity using sequential steps of acid and acetone precipitation, followed by...
The extracellular peroxidase from Streptomyces albidoflavus BSII#1 was purified to near homogeneity using sequential steps of acid and acetone precipitation, followed by ultrafiltration. The purified peroxidase was characterised and tested for the ability to catalyse coupling reactions between selected phenolic monomer pairs. A 46-fold purification of the peroxidase was achieved, and it was shown to be a 46 kDa haem peroxidase. Unlike other actinobacteria-derived peroxidases, it was only inhibited (27 % inhibition) by relatively high concentrations of sodium azide (5 mM) and was capable of oxidising eleven (2,4-dichlorophenol, 2,6-dimethoxyphenol, 4-tert-butylcatechol, ABTS, caffeic acid, catechol, guaiacol, l-DOPA, o-aminophenol, phenol, pyrogallol) of the seventeen substrates tested. The peroxidase remained stable at temperatures of up to 80 °C for 60 min and retained >50 % activity after 24 h between pH 5.0-9.0, but was most sensitive to incubation with hydrogen peroxide (HO; 0.01 mM), l-cysteine (0.02 mM) and ascorbate (0.05 mM) for one hour. It was significantly inhibited by all organic solvents tested (p ≤ 0.05). The K and V values of the partially purified peroxidase with the substrate 2,4-DCP were 0.95 mM and 0.12 mmol min, respectively. The dyes reactive blue 4, reactive black 5, and Azure B, were all decolourised to a certain extent: approximately 30 % decolourisation was observed after 24 h (1 μM dye). The peroxidase successfully catalysed coupling reactions between several phenolic monomer pairs including catechin-caffeic acid, catechin-catechol, catechin-guaiacol and guaiacol-syringaldazine under the non-optimised conditions used in this study. Genome sequencing confirmed the identity of strain BSII#1 as a S. albidoflavus strain. In addition, the genome sequence revealed the presence of one peroxidase gene that includes the twin arginine translocation signal sequence of extracellular proteins. Functional studies confirmed that the peroxidase produced by S. albidoflavus BSII#1 is part of the dye-decolourising peroxidase (DyP-type) family.
Topics: Amino Acid Sequence; Bacterial Proteins; Biocatalysis; Coloring Agents; Enzyme Inhibitors; Genome, Bacterial; Hydrogen-Ion Concentration; Kinetics; Oxidative Coupling; Peroxidase; Phenols; Protein Sorting Signals; Streptomyces; Substrate Specificity; Temperature
PubMed: 33051013
DOI: 10.1016/j.enzmictec.2020.109654 -
Chemistry (Weinheim An Der Bergstrasse,... Jun 2021Developing highly active and sensitive peroxidase mimics for -cysteine ( -Cys) colorimetric detection is very important for biotechnology and medical diagnosis. Herein,...
Developing highly active and sensitive peroxidase mimics for -cysteine ( -Cys) colorimetric detection is very important for biotechnology and medical diagnosis. Herein, polyoxometalate-doped porous Co O composite (NiMo @Co O ) was designed and prepared for the first time. Compared with pure and commercial Co O , NiMo @Co O (n) composites exhibit the enhanced peroxidase-mimicking activities and stabilities due to the strong synergistic effect between porous Co O and multi-electron NiMo clusters. Moreover, the peroxidase-mimicking activities of NiMo @Co O (n) composites are heavily dependent on the doping mass of NiMo , and the optimized NiMo @Co O (2) exhibits the superlative peroxidase-mimicking activity. More importantly, a sensitive -Cys colorimetric detection is developed with the sensitivity of 0.023 μM and the detection limit at least 0.018 μM in the linear range of 1-20 μM, which is by far the best enzyme-mimetic performances, to the best our knowledge.
Topics: Biosensing Techniques; Colorimetry; Peroxidase; Peroxidases; Porosity
PubMed: 33938042
DOI: 10.1002/chem.202100846 -
Angewandte Chemie (International Ed. in... Jan 2022Herein, we report the substrate induced generation of a transient catalytic microenvironment from a single amino acid functionalized fatty acid in presence of a cofactor...
Herein, we report the substrate induced generation of a transient catalytic microenvironment from a single amino acid functionalized fatty acid in presence of a cofactor hemin. The catalytic state accessed under non-equilibrium conditions showed acceleration of peroxidase activity resulting in degradation of the substrate and subsequently led to disassembly. Equilibrated systems could not access the three-dimensional microphases and showed substantially lower catalytic activity. Further, the assembled state showed latent catalytic function (promiscuity) to hydrolyze a precursor to yield the same substrate. Consequently, the assembly demonstrated protometabolism by exploiting the peroxidase-hydrolase cascade to augment the lifetime and the mechanical properties of the catalytic state.
Topics: Peroxidase
PubMed: 34767668
DOI: 10.1002/anie.202111857 -
BMC Microbiology Apr 2023Environmental contamination by phenol has been reported in both aquatic and atmospheric environments. This study aimed to separate and purify the peroxidase enzyme from...
Environmental contamination by phenol has been reported in both aquatic and atmospheric environments. This study aimed to separate and purify the peroxidase enzyme from bacteria that degrade phenol from wastewater sources. An enrichment culture of MSM was used to screen 25 bacterial isolates from different water samples for peroxidase production, six of the isolates exhibited high levels of peroxidase enzyme activity. Qualitative analysis of peroxidase revealed that isolate No. 4 had the highest halo zones (Poly-R478: 14.79 ± 0.78 mm, Azure B: 8.81 ± 0.61 mm). The promising isolate was identified as Bacillus aryabhattai B8W22 by 16S rRNA gene sequencing with accession number OP458197. As carbon and nitrogen sources, mannitol and sodium nitrate were utilized to achieve maximum peroxidase production. A 30-h incubation period was used with pH 6.0, 30 °C, mannitol, and sodium nitrate, respectively, for maximal production of peroxidase. Purified peroxidase enzyme showed 0.012 U/mg specific activity, and SDS-PAGE analysis indicated a molecular weight of 66 kDa. The purified enzyme exhibits maximum activity and thermal stability at pH values of 4.0 and 8.0, respectively, with maximum activity at 30 °C and complete thermal stability at 40 °C. In the purified enzyme, the Km value was 6.942 mg/ml and the Vmax value was 4.132 mol/ml/hr, respectively. The results demonstrated that Bacillus aryabhattai B8W22 has promising potential for degrading phenols from various phenol-polluted wastewater sources.
Topics: Phenol; Peroxidase; Wastewater; RNA, Ribosomal, 16S; Phenols; Peroxidases; Hydrogen-Ion Concentration
PubMed: 37120512
DOI: 10.1186/s12866-023-02850-9 -
Nanoscale May 2023Peroxidase-based assays are the most extensively used in bioanalytical sensors because of their simple colorimetric readout and high sensitivity owing to enzymatic... (Comparative Study)
Comparative Study
Peroxidase-based assays are the most extensively used in bioanalytical sensors because of their simple colorimetric readout and high sensitivity owing to enzymatic signal amplification. To improve the stability, modification, and cost of protein-based enzymes, such as horseradish peroxidase (HRP), various enzyme mimics, such as DNAzymes and nanozymes, have emerged over the last few decades. In this study, we compared the peroxidase activities of HRP, a G-quadruplex (G4)-hemin DNAzyme, and FeO nanozymes in terms of activity and stability under different conditions. The reactions were much slower at pH 7 than at pH 4. At pH 4, the turnover rate of HRP (375 s) was faster than that of G4 DNAzyme (0.14 s) and FeO (6.1 × 10 s, calculated by surface Fe concentration). When normalized to mass concentrations, the trend was the same. Through observation of the reaction for a long time of 2 h, the changes in the color and UV-vis spectra were also different for these catalysts, indicating different reaction mechanisms among these catalysts. Moreover, different buffers and nanozyme sizes were found to influence the activity of the catalysts. FeO showed the highest stability compared to HRP and G4 DNAzyme after a catalytic reaction or incubation with HO for a few hours. This study helps to understand the properties of catalysts and the development of novel catalysts with enzyme-mimicking activities for application in various fields.
Topics: DNA, Catalytic; G-Quadruplexes; Hemin; Horseradish Peroxidase; Hydrogen Peroxide; Peroxidase; Peroxidases
PubMed: 37093157
DOI: 10.1039/d3nr01098h -
Microbiology Spectrum Feb 2022Heme-containing peroxidases are widely distributed in the animal and plant kingdoms and play an important role in host defense by generating potent oxidants....
Heme-containing peroxidases are widely distributed in the animal and plant kingdoms and play an important role in host defense by generating potent oxidants. Myeloperoxidase (MPO), the prototype of heme-containing peroxidases, exists in neutrophils and monocytes. MPO has a broad spectrum of microbial killing. The difficulty of producing MPO at a large scale hinders its study and utilization. This study aimed to overexpress recombinant human MPO and characterize its microbicidal activities and . A human HEK293 cell line stably expressing recombinant MPO (rMPO) was established as a component of this study. rMPO was overexpressed and purified for studies on its biochemical and enzymatic properties, as well as its microbicidal activities. In this study, rMPO was secreted into culture medium as a monomer. rMPO revealed enzymatic activity similar to that of native MPO. rMPO, like native MPO, was capable of killing a broad spectrum of microorganisms, including Gram-negative and -positive bacteria and fungi, at low nM levels. Interestingly, rMPO could kill antibiotic-resistant bacteria, making it very useful for treatment of nosocomial infections and mixed infections. The administration of rMPO significantly reduced the morbidity and mortality of murine lung infections induced by Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus. In animal safety tests, the administration of 100 nM rMPO via tail vein did not result in any sign of toxic effects. Taken together, the data suggest that rMPO purified from a stably expressing human cell line is a new class of antimicrobial agents with the ability to kill a broad spectrum of pathogens, including bacteria and fungi with or without drug resistance. Over the past 2 decades, more than 20 new infectious diseases have emerged. Unfortunately, novel antimicrobial therapeutics are discovered at much lower rates. Infections caused by resistant microorganisms often fail to respond to conventional treatment, resulting in prolonged illness, greater risk of death, and high health care costs. Currently, this is best seen with the lack of a cure for coronavirus disease 2019 (COVID-19). To combat such untreatable microorganisms, there is an urgent need to discover new classes of antimicrobial agents. Myeloperoxidase (MPO) plays an important role in host defense. The difficulty of producing MPO on a large scale hinders its study and utilization. We have produced recombinant MPO at a large scale and have characterized its antimicrobial activities. Most importantly, recombinant MPO significantly reduced the morbidity and mortality of murine pneumonia induced by Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus. Our data suggest that recombinant MPO from human cells is a new class of antimicrobials with a broad spectrum of activity.
Topics: Acute Disease; Animals; Anti-Infective Agents; Candida albicans; Drug Resistance, Bacterial; Escherichia coli; Female; HEK293 Cells; Humans; Hydrogen Peroxide; Male; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred C57BL; Peroxidase; Pneumonia, Bacterial; Pseudomonas Infections; Pseudomonas aeruginosa; Recombinant Proteins; Staphylococcal Infections; Staphylococcus aureus
PubMed: 35019674
DOI: 10.1128/spectrum.00522-21