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Biosensors Jun 2023Chemiluminescence is widely used for hydrogen peroxide detection, mainly exploiting the highly sensitive peroxidase-luminol-HO system. Hydrogen peroxide plays an...
Chemiluminescence is widely used for hydrogen peroxide detection, mainly exploiting the highly sensitive peroxidase-luminol-HO system. Hydrogen peroxide plays an important role in several physiological and pathological processes and is produced by oxidases, thus providing a straightforward way to quantify these enzymes and their substrates. Recently, biomolecular self-assembled materials obtained by guanosine and its derivatives and displaying peroxidase enzyme-like catalytic activity have received great interest for hydrogen peroxide biosensing. These soft materials are highly biocompatible and can incorporate foreign substances while preserving a benign environment for biosensing events. In this work, a self-assembled guanosine-derived hydrogel containing a chemiluminescent reagent (luminol) and a catalytic cofactor (hemin) was used as a HO-responsive material displaying peroxidase-like activity. Once loaded with glucose oxidase, the hydrogel provided increased enzyme stability and catalytic activity even in alkaline and oxidizing conditions. By exploiting 3D printing technology, a smartphone-based portable chemiluminescence biosensor for glucose was developed. The biosensor allowed the accurate measurement of glucose in serum, including both hypo- and hyperglycemic samples, with a limit of detection of 120 µmol L. This approach could be applied for other oxidases, thus enabling the development of bioassays to quantify biomarkers of clinical interest at the point of care.
Topics: Glucose; Peroxidase; Hydrogen Peroxide; Luminol; Luminescence; Hydrogels; Smartphone; Peroxidases; Oxidoreductases; Glucose Oxidase; Biosensing Techniques; Luminescent Measurements; Limit of Detection
PubMed: 37367015
DOI: 10.3390/bios13060650 -
Biomolecules Jun 2021In the present study, soybean peroxidase (SBP) was covalently immobilized onto two functionalized photocatalytic supports (TiO and ZnO) to create novel hybrid...
In the present study, soybean peroxidase (SBP) was covalently immobilized onto two functionalized photocatalytic supports (TiO and ZnO) to create novel hybrid biocatalysts (TiO-SBP and ZnO-SBP). Immobilization caused a slight shift in the pH optima of SBP activity (pH 5.0 to 4.0), whereas the free and TiO-immobilized SBP showed similar thermal stability profiles. The newly developed hybrid biocatalysts were used for the degradation of 21 emerging pollutants in the presence and absence of 1-hydroxy benzotriazole (HOBT) as a redox mediator. Notably, all the tested pollutants were not equally degraded by the SBP treatment and some of the tested pollutants were either partially degraded or appeared to be recalcitrant to enzymatic degradation. The presence of HOBT enhanced the degradation of the pollutants, while it also inhibited the degradation of some contaminants. Interestingly, TiO and ZnO-immobilized SBP displayed better degradation efficiency of a few emerging pollutants than the free enzyme. Furthermore, a combined enzyme-chemical oxidation remediation strategy was employed to degrade two recalcitrant pollutants, which suggest a novel application of these novel hybrid peroxidase-photocatalysts. Lastly, the reusability profile indicated that the TiO-SBP hybrid biocatalyst retained up to 95% degradation efficiency of a model pollutant (2-mercaptobenzothiazole) after four consecutive degradation cycles.
Topics: Biocatalysis; Environmental Pollutants; Enzymes, Immobilized; Peroxidase; Plant Proteins; Glycine max; Titanium; Zinc Oxide
PubMed: 34204500
DOI: 10.3390/biom11060904 -
Methods in Cell Biology 2021Neutralization of pathogens by phagocytic immune cells requires the biogenesis of a compartmentalized hotspot of reactive species called the phagosome. One of these...
Neutralization of pathogens by phagocytic immune cells requires the biogenesis of a compartmentalized hotspot of reactive species called the phagosome. One of these reactive species is hypochlorous acid (HOCl), produced by the enzyme myeloperoxidase (MPO) after the phagosome fuses with the lysosome. Mapping HOCl during phagosome maturation can report on pathogen killing and offer insights into regulation of MPO activity, mechanisms of resistance and host-pathogen interactions. However, this has been difficult because of a lack of a suitable method to chemically map a transient organelle with pH fluctuations like the phagosome. Here, we detail a protocol for quantifying HOCl dynamics in phagosomes using a fluorescent DNA-based reporter. Compared to traditional methods of visualizing HOCl or measuring MPO activity, this method offers sub-cellular spatial resolution and the capacity to assay HOCl production with single cell resolution.
Topics: Hypochlorous Acid; Neutrophils; Peroxidase; Phagocytes; Phagosomes
PubMed: 34225911
DOI: 10.1016/bs.mcb.2020.10.006 -
Scientific Reports Jun 2022MPO-derived oxidants including HOCl contribute to tissue damage and the initiation and propagation of inflammatory diseases. The search for small molecule inhibitors of...
MPO-derived oxidants including HOCl contribute to tissue damage and the initiation and propagation of inflammatory diseases. The search for small molecule inhibitors of myeloperoxidase, as molecular tools and potential drugs, requires the application of high throughput screening assays based on monitoring the activity of myeloperoxidase. In this study, we have compared three classes of fluorescent probes for monitoring myeloperoxidase-derived hypochlorous acid, including boronate-, aminophenyl- and thiol-based fluorogenic probes and we show that all three classes of probes are suitable for this purpose. However, probes based on the coumarin fluorophore turned out to be not reliable indicators of the inhibitors' potency. We have also determined the rate constants of the reaction between HOCl and the probes and they are equal to 1.8 × 10 Ms for coumarin boronic acid (CBA), 1.1 × 10 Ms for fluorescein based boronic acid (FLBA), 3.1 × 10 Ms for 7-(p-aminophenyl)-coumarin (APC), 1.6 × 10 Ms for 3'-(p-aminophenyl)-fluorescein (APF), and 1 × 10 Ms for 4-thiomorpholino-7-nitrobenz-2-oxa-1,3-diazole (NBD-TM). The high reaction rate constant of NBD-TM with HOCl makes this probe the most reliable tool to monitor HOCl formation in the presence of compounds showing HOCl-scavenging activity.
Topics: Boronic Acids; Coumarins; Fluoresceins; Fluorescent Dyes; Hypochlorous Acid; Peroxidase
PubMed: 35660769
DOI: 10.1038/s41598-022-13317-8 -
PeerJ 2023Hydrogen sulfide (HS), as an endogenous gas signaling molecule, plays an important role in plant growth regulation and resistance to abiotic stress. This study aims to...
Hydrogen sulfide (HS), as an endogenous gas signaling molecule, plays an important role in plant growth regulation and resistance to abiotic stress. This study aims to investigate the mechanism of exogenous HS on the growth and development of seedlings under salt stress and to determine the optimal concentration for foliar application. To investigate the regulatory effects of exogenous HS (donor sodium hydrosulfide, NaHS) at concentrations ranging from 0 to 1 mM on reactive oxygen species (ROS), antioxidant system, and osmoregulation in seedlings under 300 mM NaCl stress. The growth of seedlings was inhibited by salt stress, which resulted in a decrease in the leaf relative water content (LRWC), specific leaf area (SLA), and soluble sugar content in leaves, elevated activity levels of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); and accumulated superoxide anion (O), proline, malondialdehyde (MDA), and soluble protein content in leaves; and increased L-cysteine desulfhydrase (LCD) activity and endogenous HS content. This indicated that a high level of ROS was produced in the leaves of seedlings and seriously affected the growth and development of seedlings. The exogenous application of different concentrations of NaHS reduced the content of O , proline and MDA, increased the activity of antioxidant enzymes and the content of osmoregulators (soluble sugars and soluble proteins), while the LCD enzyme activity and the content of endogenous HS were further increased with the continuous application of exogenous HS. The inhibitory effects of salt stress on the growth rate of plant height and ground diameter, the LRWC, biomass, and SLA were effectively alleviated. A comprehensive analysis showed that the LRWC, POD, and proline could be used as the main indicators to evaluate the alleviating effect of exogenous HS on seedlings under salt stress. The optimal concentration of exogenous HS for seedlings under salt stress was 0.025 mM. This study provides an important theoretical foundation for understanding the salt tolerance mechanism of and for cultivating high-quality germplasm resources.
Topics: Salt Tolerance; Hydrogen Sulfide; Reactive Oxygen Species; Seedlings; Antioxidants; Salt Stress; Peroxidase; Peroxidases; Coloring Agents; Deuterium
PubMed: 37641597
DOI: 10.7717/peerj.15881 -
Redox Report : Communications in Free... Mar 2017Atherosclerosis is the main pathophysiological process underlying coronary artery disease (CAD). Acute complications of atherosclerosis, such as myocardial infarction,... (Review)
Review
Atherosclerosis is the main pathophysiological process underlying coronary artery disease (CAD). Acute complications of atherosclerosis, such as myocardial infarction, are caused by the rupture of vulnerable atherosclerotic plaques, which are characterized by thin, highly inflamed, and collagen-poor fibrous caps. Several lines of evidence mechanistically link the heme peroxidase myeloperoxidase (MPO), inflammation as well as acute and chronic manifestations of atherosclerosis. MPO and MPO-derived oxidants have been shown to contribute to the formation of foam cells, endothelial dysfunction and apoptosis, the activation of latent matrix metalloproteinases, and the expression of tissue factor that can promote the development of vulnerable plaque. As such, detection, quantification and imaging of MPO mass and activity have become useful in cardiac risk stratification, both for disease assessment and in the identification of patients at risk of plaque rupture. This review summarizes the current knowledge about the role of MPO in CAD with a focus on its possible roles in plaque rupture and recent advances to quantify and image MPO in plasma and atherosclerotic plaques.
Topics: Apoptosis; Biomarkers; Coronary Artery Disease; Endothelium, Vascular; Humans; Lipoproteins, HDL; Lipoproteins, LDL; Luminescent Measurements; Luminol; Molecular Imaging; Peroxidase; Plaque, Atherosclerotic; Thrombosis
PubMed: 27884085
DOI: 10.1080/13510002.2016.1256119 -
Genes Aug 2023Although thaumatin-like proteins () are involved in resistance to a variety of fungal diseases, whether the 5 and 6 genes in tomato plants () confer resistance to the...
Although thaumatin-like proteins () are involved in resistance to a variety of fungal diseases, whether the 5 and 6 genes in tomato plants () confer resistance to the pathogenesis of soil-borne diseases has not been demonstrated. In this study, five soil-borne diseases (fungal pathogens: , , and ; bacterial pathogens: subsp. and ) were used to infect susceptible "No. 5" and disease-resistant "S-55" tomato cultivars. We found that and transcript levels were higher in susceptible cultivars treated with the three fungal pathogens than in those treated with the two bacterial pathogens and that transcript levels varied depending on the pathogen. Moreover, the and transcript levels were much higher in disease-resistant cultivars than in disease-susceptible cultivars, and the and transcript levels were higher in cultivars treated with the same fungal pathogen than in those treated with bacterial pathogens. transcript levels were higher than . and overexpression and gene-edited transgenic mutants were generated in both susceptible and resistant cultivars. Overexpression and knockout increased and decreased resistance to the five diseases, respectively. Transgenic plants overexpressing and inhibited the activities of peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) after inoculation with fungal pathogens, and the activities of POD, SOD, and APX were similar to those of fungi after infection with bacterial pathogens. The activities of CAT were increased, and the activity of β-1,3-glucanase was increased in both the fungal and bacterial treatments. Overexpressed plants were more resistant than the control plants. After and knockout plants were inoculated, POD, SOD, and APX had no significant changes, but CAT activity increased and decreased significantly after the fungal and bacterial treatments, contrary to overexpression. The activity of β-1,3-glucanase decreased in the treatment of the five pathogens, and the knocked-out plants were more susceptible to disease than the control. In summary, this study contributes to the further understanding of disease resistance mechanisms in tomato plants.
Topics: Solanum lycopersicum; Peroxidase; Superoxide Dismutase; Peroxidases; Ascorbate Peroxidases
PubMed: 37628673
DOI: 10.3390/genes14081622 -
Brazilian Journal of Microbiology :... Dec 2022Glutathione (GSH) and peroxidase (POD) are biomolecules of interest in the global market; thus, it is desirable to seek ways to increase their production. Magnetic field...
Glutathione (GSH) and peroxidase (POD) are biomolecules of interest in the global market; thus, it is desirable to seek ways to increase their production. Magnetic field (MF) application is one of the technologies used in cultivation that has shown promising results to increase bioproducts. Therefore, this study aimed at evaluating the influence of MFs on GSH and POD production by Saccharomyces cerevisiae ATCC 7754. Different periods of MF application (35 mT) were evaluated over 72 h. The highest GSH production was reached in 48 h of cultivation in assays MF 0-24 (155.32 ± 9.12 mg L) and MF 0-72 (149.27 ± 3.62 mg L), which showed an increase of 121.9 % and 113 %, respectively, by comparison with the control without any MF application. The highest POD activity was achieved when MFs were applied throughout the culture (36.31 U mg) and POD productivity of 0.72 U mg h. MF application throughout cultivation proved to be a promising strategy since all responses increased, i.e., GSH concentration, GSH productivity, POD activity, and POD productivity increased 113.7 %, 113 %, 20.4 %, and 28.6 %, respectively. This study is one of the first to consider MFs as a viable and low-cost alternative to produce GSH and POD in bioprocesses.
Topics: Saccharomyces cerevisiae; Peroxidase; Glutathione; Peroxidases; Oxidoreductases; Magnetic Fields; Antioxidants
PubMed: 36199005
DOI: 10.1007/s42770-022-00836-9 -
Ultrasonics Sonochemistry Mar 2021The activation mechanism of peroxidase by ultrasound was investigated. The catalysis performance of peroxidase with ultrasound treatment was prior to the controls...
The activation mechanism of peroxidase by ultrasound was investigated. The catalysis performance of peroxidase with ultrasound treatment was prior to the controls determined by UV-visible spectra and Fourier transform infrared spectra. The transformation of tryptophan residues in peroxidase led to the increase of a-helix and anti-parallel content in the secondary structure, and the content of p-sheet, p-turn and random coil in the secondary structure. In addition, under the atomic force microscope, under ultrasonic treatment, the large molecular clusters of tyrosinase are broken down into small molecular clusters. The current results showed that the activity of peroxidase is activated under ultrasonic treatment, which is mainly caused by ultrasound without conformational change, the catalytic center is exposed, and the affinity with the substrate is stronger.
Topics: Enzyme Activation; Peroxidase; Spectrum Analysis; Ultrasonic Waves
PubMed: 33096324
DOI: 10.1016/j.ultsonch.2020.105362 -
Molecules (Basel, Switzerland) Jul 2022The peroxidase-like activity of vitamin B6 (VB6) was firstly demonstrated by catalyzing the peroxidase chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) at the...
The peroxidase-like activity of vitamin B6 (VB6) was firstly demonstrated by catalyzing the peroxidase chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) at the existence of HO. The influence of different factors on the catalytic property of VB6, including pH, temperature, VB6 concentration, and incubation time, were investigated. The steady-state kinetic study results indicate that VB6 possesses higher affinity to HO than natural horseradish peroxidase and some other peroxidase mimics. Besides, the radical quenching experiment results confirm that hydroxyl radical (•OH) accounts for the catalytic process. Based on the excellent peroxidase-like catalytic activity of VB6, the colorimetric methods for HO and gallic acid (GA) detection were developed by measuring the absorbance variance of the catalytic system. Under the optimal conditions, the linear ranges of the methods for HO and GA determination with good selectivity are 50.0-600.0 μM and 10.0-50.0 μM, respectively. In addition, the developed method was applied in the detection of HO in milk samples and evaluation of total antioxidant capacity of different tea infusions. This study may broaden the application prospect of VB6 in environmental and biomedical analysis fields, contribute to profound insight of the physiological functions of VB6, as well as lay foundation for further excavation of small-molecule peroxidase mimics.
Topics: Antioxidants; Biomimetic Materials; Colorimetry; Hydrogen Peroxide; Peroxidase; Peroxidases; Vitamin B 6
PubMed: 35807507
DOI: 10.3390/molecules27134262