-
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 -
Inflammation Dec 2023Inflammation and oxidative stress play a significant role in the pathogenesis of acute myeloid leukemia. While myeloperoxidase carries pro-oxidant effects,...
Inflammation and oxidative stress play a significant role in the pathogenesis of acute myeloid leukemia. While myeloperoxidase carries pro-oxidant effects, HDL-cholesterol and paraoxonase have antioxidant properties. Therefore, we evaluated serum paraoxonase, myeloperoxidase, and HDL-cholesterol levels in cases with acute myeloid leukemia. Myeloperoxidase, paraoxonase, and HDL-cholesterol levels in 40 acute myeloid leukemia patients and 18 healthy individuals were determined. The relationship between these parameters and other prognostic factors, as well as their association with response to chemotherapy, was investigated. Myeloperoxidase levels were higher, while paraoxonase and HDL-cholesterol levels were lower in acute myeloid leukemia cases compared to the control group (p < 0.001, p < 0.001, p = 0.006, respectively). The myeloperoxidase level was significantly negatively correlated with paraoxonase and HDL-c levels (r = - 0.64, p < 0.001; r = - 0.27, p = 0.02, respectively). Paraoxonase level was positively correlated with HDL level (r = 0.34, p = 0.04). Lactate dehydrogenase level was negatively correlated with HDL-c and paraoxonase levels and positively correlated with myeloperoxidase level (r = - 0.37, p = 0.019; r = - 0.35, p = 0.04; r = 0.45, p = 0.03, respectively). Following complete remission induction treatment, cases with complete remission had lower myeloperoxidase levels and higher HDL-cholesterol and paraoxonase levels compared to other cases (p = 0.03, p = 0.01, p = 0.04, respectively). Myeloperoxidase levels are higher, while paraoxonase and HDL-cholesterol levels are lower in acute myeloid leukemia cases. The obtained findings emphasize the potential importance of inflammation and oxidative stress in the pathogenesis of acute myeloid leukemia. These parameters can be used as biomarkers for prognosis prediction and prediction of response to chemotherapy.
Topics: Humans; Aryldialkylphosphatase; Peroxidase; Oxidative Stress; Cholesterol, HDL; Inflammation
PubMed: 37917329
DOI: 10.1007/s10753-023-01924-0 -
Mikrochimica Acta Dec 2023Carbon-coated copper nanocrystals (CuNCs) with peroxidase-like activity were hydrothermally prepared by using copper acetate, citric acid (CA) and histidine (His) as the...
Carbon-coated copper nanocrystals (CuNCs) with peroxidase-like activity were hydrothermally prepared by using copper acetate, citric acid (CA) and histidine (His) as the precursors. Various shaped CuNCs, including urchin-like, slab-like and spherical appearance were facilely prepared by addition of different amount of NaNO in the precursor solutions. When 3,3',5,5'-tetramethylbenzidine (TMB) was used as the substrate, the CuNCs with urchin-like appearance have greatest peroxidase-like activity and their Michaelis-Menten constant (K) and the maximum rate constant (ν) are respectively 8.8 and 1.2 times higher than that obtained from horseradish peroxidase (HRP). The production of reactive oxygen species (ROS) was confirmed by radical quenching and electron spin resonance (ESR) tests. Subsequent studies have found that the CuNCs catalyzed color reaction of TMB can be selectively quenched by the environmental pollutant 2,4-dinitrophenylhydrazine (2,4-DNPH). Thus a new colorimetric method for the determination of 2,4-DNPH with a linear range of 0.60-20 µM was developed and a limit of detection (LOD) as low as 0.166 µM was achieved. The results obtained not only reveal the tunability of the peroxidase-like activity of Cu-based nanomaterials, but also provide a new method for the sensitive determination of environmental contaminate.
Topics: Peroxidase; Copper; Carbon; Colorimetry; Hydrogen Peroxide; Biomimetic Materials; Nanoparticles
PubMed: 38110783
DOI: 10.1007/s00604-023-06127-w -
Scientific Reports Aug 2023In recent years, the peroxidase enzymes have generated wide interest in several industrial processes, such as wastewater treatments, food processing, pharmaceuticals,...
In recent years, the peroxidase enzymes have generated wide interest in several industrial processes, such as wastewater treatments, food processing, pharmaceuticals, and the production of fine chemicals. However, the low stability of the peroxidases in the presence of hydrogen peroxide (HO) has limited its commercial use. In the present work, the effect of HO on the inactivation of horseradish peroxidase (HRP) was evaluated. Three states of HRP (E, E, and E) were identified. While in the absence of HO, the resting state E was observed, in the presence of low and high concentrations of HO, E and E were found, respectively. The results showed that HRP catalyzed the HO decomposition, forming the species E, which was catalytically inactive. Results suggest that this loss of enzymatic activity is an intrinsic characteristic of the studied HRP. A model from a modified version of the Dunford mechanism of peroxidases was developed, which was validated against experimental data and findings reported by the literature.
Topics: Horseradish Peroxidase; Hydrogen Peroxide; Kinetics; Peroxidases; Peroxidase
PubMed: 37591893
DOI: 10.1038/s41598-023-39687-1 -
ACS Applied Bio Materials Sep 2023Nanozymes are nanoparticles with intrinsic enzyme-mimicking properties that have become more prevalent because of their ability to outperform conventional enzymes by... (Review)
Review
Nanozymes are nanoparticles with intrinsic enzyme-mimicking properties that have become more prevalent because of their ability to outperform conventional enzymes by overcoming their drawbacks related to stability, cost, and storage. Nanozymes have the potential to manipulate active sites of natural enzymes, which is why they are considered promising candidates to function as enzyme mimetics. Several microscopy- and spectroscopy-based techniques have been used for the characterization of nanozymes. To date, a wide range of nanozymes, including catalase, oxidase, peroxidase, and superoxide dismutase, have been designed to effectively mimic natural enzymes. The activity of nanozymes can be controlled by regulating the structural and morphological aspects of the nanozymes. Nanozymes have multifaceted benefits, which is why they are exploited on a large scale for their application in the biomedical sector. The versatility of nanozymes aids in monitoring and treating cancer, other neurodegenerative diseases, and metabolic disorders. Due to the compelling advantages of nanozymes, significant research advancements have been made in this area. Although a wide range of nanozymes act as potent mimetics of natural enzymes, their activity and specificities are suboptimal, and there is still room for their diversification for analytical purposes. Designing diverse nanozyme systems that are sensitive to one or more substrates through specialized techniques has been the subject of an in-depth study. Hence, we believe that stimuli-responsive nanozymes may open avenues for diagnosis and treatment by fusing the catalytic activity and intrinsic nanomaterial properties of nanozyme systems.
Topics: Nanostructures; Nanoparticles; Peroxidase; Peroxidases; Microscopy
PubMed: 37590090
DOI: 10.1021/acsabm.3c00253 -
Journal of Inorganic Biochemistry Oct 2023The dehaloperoxidase-hemoglobin (DHP), first isolated from the coelom of a marine terebellid polychaete, Amphitrite ornata, is an example of a multi-functional heme... (Comparative Study)
Comparative Study
The dehaloperoxidase-hemoglobin (DHP), first isolated from the coelom of a marine terebellid polychaete, Amphitrite ornata, is an example of a multi-functional heme enzyme. Long known for its reversible oxygen (O) binding, further studies have established DHP activity as a peroxidase, oxidase, oxygenase, and peroxygenase. The specific reactivity depends on substrate binding at various internal and external binding sites. This study focuses on comparison of the binding and reactivity of the substrate 2,4-dichlorophenol (DCP) in the isoforms DHPA and B. There is strong interest in the degradation of DCP because of its wide use in the chemical industry, presence in waste streams, and particular reactivity to form dioxins, some of the most toxic compounds known. The catalytic efficiency is 3.5 times higher for DCP oxidation in DHPB than DHPA by a peroxidase mechanism. However, DHPA and B both show self-inhibition even at modest concentrations of DCP. This phenomenon is analogous to the self-inhibition of 2,4,6-trichlorophenol (TCP) at higher concentration. The activation energies of the electron transfer steps in DCP in DHPA and DHPB are 19.3 ± 2.5 and 24.3 ± 3.2 kJ/mol, respectively, compared to 37.2 ± 6.5 kJ/mol in horseradish peroxidase (HRP), which may be a result of the more facile electron transfer of an internally bound substrate in DHPA. The x-ray crystal structure of DHPA bound with DCP determined at 1.48 Å resolution, shows tight substrate binding inside the heme pocket of DHPA (PDB 8EJN). This research contributes to the studies of DHP as a naturally occurring bioremediation enzyme capable of oxidizing a wide range of environmental pollutants.
Topics: Chlorophenols; Coloring Agents; Heme; Peroxidase; Peroxidases; Phenols
PubMed: 37480762
DOI: 10.1016/j.jinorgbio.2023.112332 -
Analytical Methods : Advancing Methods... Aug 2023The myeloperoxidase (MPO)/HO-Cl enzymatic reaction system and its product hypochlorous acid (HOCl) are closely related to many disease processes, and new methods to...
The myeloperoxidase (MPO)/HO-Cl enzymatic reaction system and its product hypochlorous acid (HOCl) are closely related to many disease processes, and new methods to detect the levels of HOCl and MPO are being focused on. MPO is the only known enzyme for the catalytic production of HOCl in biological systems; therefore, monitoring the HOCl levels is a selective and direct readout of MPO activity. This study reported a simple and efficient fluorescence assay of HOCl and MPO activity and inhibition. Highly fluorescent CdS quantum dots (CdS QDs) were prepared in one pot where NaOH-pretreated egg white served as a stabilizer. These CdS QDs exhibit strong green emission centered at 550 nm and enable rapid and selective fluorescence response to HOCl with a linear detection range of 8.0-250 μM and a limit of detection (LOD) of 2.5 μM. Moreover, the CdS QDs were further applied for sensing MPO based on the fluorescence quenching exerted by its reaction product HOCl. Detection of MPO is accomplished with a linear range from 0.1 to 40 mU mL (1 U is the MPO concentration for catalysis of 1 micromolar substrate per minute) and a LOD of 0.06 mU mL. The developed synthesis method can be applied to large-scale synthesis of CdS QDs, and the strategy to sense HOCl and MPO activity and inhibition has potential biomedical applications such as clinical diagnosis and drug screening.
Topics: Peroxidase; Egg White; Hydrogen Peroxide; Hypochlorous Acid; Quantum Dots; Coloring Agents
PubMed: 37591805
DOI: 10.1039/d3ay01148h -
Anais Da Academia Brasileira de Ciencias 2023The present study aimed to investigate the response of soybean cultivars with different susceptibility levels to the root-knot nematode Meloidogyne javanica at varied...
The present study aimed to investigate the response of soybean cultivars with different susceptibility levels to the root-knot nematode Meloidogyne javanica at varied time intervals by analyzing the initial plant-nematode interaction using antioxidant enzymes as oxidative stress markers. A 4 × 4 × 2 factorial method with 5 repetitions was used to analyze 4 soybean cultivars at 4 different collection times-6, 12, 24, and 48 h-with and without M. javanica inoculation. The parameters evaluated were the activities of antioxidant enzymes phenol peroxidase (POX) and ascorbate peroxidase (APX); the concentrations of hydrogen peroxide (H2O2) and malondialdehyde (MDA); and the number of M. javanica juveniles penetrated into each plant. H2O2 concentration varied among the cultivars with and without inoculation and at different collection times as indicated by MDA concentration and POX and APX activities, demonstrating a rapid response of the host to an infection by M. javanica. Oxidative stress caused by M. javanica did not vary among the soybean cultivars regardless of their susceptibility level; however, the antioxidant enzymes POX and APX responded according to the susceptibility level of the cultivars.
Topics: Animals; Antioxidants; Glycine max; Tylenchoidea; Hydrogen Peroxide; Oxidative Stress; Peroxidases; Peroxidase; Ascorbate Peroxidases
PubMed: 37436197
DOI: 10.1590/0001-3765202320201328 -
Mikrochimica Acta Mar 2024Transition metal carbides modified by Au nanoparticles (Au/TiC) were synthesized and developed as a colorimetric sensor for the determination of HO and ampicillin. The...
Transition metal carbides modified by Au nanoparticles (Au/TiC) were synthesized and developed as a colorimetric sensor for the determination of HO and ampicillin. The surface electrical properties of TiC were changed, and Au nanoparticles (AuNPs) and gold growth solution were synthesized simultaneously. Au/TiC was obtained by seed growth method with AuNPs modified on the surface of transition metal carbides, nitrides or carbon-nitrides (TiC MXenes). The synthesized AuNPs and TiC had no peroxidase-like activity, but Au/TiC had. The peroxidase catalytic mechanism was due to electron transfer. The peroxidase activity of Au/TiC can be utilized for the determination of HO. The linear range of Au/TiC for HO was 1-60 µM, and the detection limit was 0.12 µM (S/N = 3). A colometric sensor for ampicillin detection based on Au/TiC was further constructed since S in ampicillin formed an Au-S bond with Au/TiC, leading to the weakening of its peroxidase-like property. The change of peroxidase-like property attenuated oxidation of TMB, and the ampicillin content was inversely proportional to the concentration of oxidized TMB, and the blue color of solution faded, which enabled the determination of ampicillin. The linear range for ampicillin was 0.005-0.5 µg mL, and the detection limit was 1.1 ng mL (S/N = 3). The sensor was applied to the detection of ampicillin in milk and human serum.
Topics: Humans; Gold; Colorimetry; Hydrogen Peroxide; Metal Nanoparticles; Titanium; Peroxidase; Peroxidases
PubMed: 38478128
DOI: 10.1007/s00604-024-06263-x -
Biochemistry. Biokhimiia Jan 2024Reactive halogen species (RHS) are highly reactive compounds that are normally required for regulation of immune response, inflammatory reactions, enzyme function, etc.... (Review)
Review
Reactive halogen species (RHS) are highly reactive compounds that are normally required for regulation of immune response, inflammatory reactions, enzyme function, etc. At the same time, hyperproduction of highly reactive compounds leads to the development of various socially significant diseases - asthma, pulmonary hypertension, oncological and neurodegenerative diseases, retinopathy, and many others. The main sources of (pseudo)hypohalous acids are enzymes from the family of heme peroxidases - myeloperoxidase, lactoperoxidase, eosinophil peroxidase, and thyroid peroxidase. Main targets of these compounds are proteins and peptides, primarily methionine and cysteine residues. Due to the short lifetime, detection of RHS can be difficult. The most common approach is detection of myeloperoxidase, which is thought to reflect the amount of RHS produced, but these methods are indirect, and the results are often contradictory. The most promising approaches seem to be those that provide direct registration of highly reactive compounds themselves or products of their interaction with components of living cells, such as fluorescent dyes. However, even such methods have a number of limitations and can often be applied mainly for in vitro studies with cell culture. Detection of reactive halogen species in living organisms in real time is a particularly acute issue. The present review is devoted to RHS, their characteristics, chemical properties, peculiarities of interaction with components of living cells, and methods of their detection in living systems. Special attention is paid to the genetically encoded tools, which have been introduced recently and allow avoiding a number of difficulties when working with living systems.
Topics: Peroxidases; Halogens; Peroxidase; Eosinophil Peroxidase; Antioxidants
PubMed: 38621746
DOI: 10.1134/S0006297924140062