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Chemistry (Weinheim An Der Bergstrasse,... Feb 2024Developing enzyme alternatives is pivotal to improving and enabling new processes in biotechnology and industry. Artificial metalloenzymes (ArMs) are combinations of...
Developing enzyme alternatives is pivotal to improving and enabling new processes in biotechnology and industry. Artificial metalloenzymes (ArMs) are combinations of protein scaffolds with metal elements, such as metal nanoclusters or metal-containing molecules with specific catalytic properties, which can be customized. Here, we engineered an ArM based on the consensus tetratricopeptide repeat (CTPR) scaffold by introducing a unique histidine residue to coordinate the hemin cofactor. Our results show that this engineered system exhibits robust peroxidase-like catalytic activity driven by the hemin. The expression of the scaffold and subsequent coordination of hemin was achieved by recombinant expression in bulk and through in vitro transcription and translation systems in water-in-oil drops. The ability to synthesize this system in emulsio paves the way to improve its properties by means of droplet microfluidic screenings, facilitating the exploration of the protein combinatorial space to discover improved or novel catalytic activities.
Topics: Hemin; Metalloproteins; Peroxidase; Metals
PubMed: 38145337
DOI: 10.1002/chem.202303254 -
Nanoscale Dec 2023Peroxidase (POD)-like nanozymes are an upcoming class of new-generation antibiotics that are efficient for broad-spectrum antibacterial action. The POD-like activity...
Peroxidase (POD)-like nanozymes are an upcoming class of new-generation antibiotics that are efficient for broad-spectrum antibacterial action. The POD-like activity employs the generation of reactive oxygen species (ROS), which have been utilized for bactericidal action. However, their intrinsic low catalytic activity and stability limit their bactericidal properties. In this study, we prepared a MoS-based nanocomposite with copper peroxide nanodots (MoS@CP) to achieve pH-dependent light-induced nanozyme-based antibacterial action. It has shown superior peroxidase and antibacterial activity at low pH. The mechanism behind the enhanced POD-like activity and high antibacterial activity was established. The mechanistic pathway involves estimating ROS generation, membrane depolarization, inner membrane permeabilization, metal ion release, and the effect of NIR on photothermal and photodynamic activities. Overall, our work highlighted the combinatorial approach for eradicating bacterial infections using enzyme-based antibacterial agents.
Topics: Copper; Peroxides; Reactive Oxygen Species; Molybdenum; Peroxidase; Peroxidases; Anti-Bacterial Agents; Coloring Agents; Hydrogen Peroxide
PubMed: 38051093
DOI: 10.1039/d3nr05458f -
BMC Plant Biology Oct 2023Salinity adversely affects okra [Abelmoschus esculentus (L.) Moench] plants by inducing osmotic and oxidative stresses. This study was designed to enhance...
AIMS
Salinity adversely affects okra [Abelmoschus esculentus (L.) Moench] plants by inducing osmotic and oxidative stresses. This study was designed to enhance salinity-induced osmotic and oxidative stress tolerance in okra plants by applying organic amendments.
METHODS
The effects of different organic amendments (municipal solid waste compost, farmyard manure (FYM) and press mud) on osmotic potential, water use efficiency, activities of antioxidant enzymes, total soluble sugar, total soluble proline, total soluble protein and malondialdehyde (MDA) contents of okra plants grown under saline conditions (50 mM sodium chloride) were evaluated in a pot experiment. The organic amendments were applied each at the rate of 5% and 10% per pot or in various combinations (compost + FYM, FYM + press mud and compost + press mud each at the rate of 2.5% and 5% per pot).
RESULTS
As compared to control, high total soluble sugar (60.41), total soluble proline (33.88%) and MDA (51%) contents and increased activities of antioxidant enzymes [superoxide dismutase (83.54%), catalase (78.61%), peroxidase (53.57%] in salinity-stressed okra plants, were indicative of oxidative stress. Salinity significantly reduced the osmotic potential (41.78%) and water use efficiency (4.75%) of okra plants compared to control. Under saline conditions, 5% (farmyard manure + press mud) was the most effective treatment, which significantly improved osmotic potential (27.05%), total soluble sugar (4.20%), total soluble protein (73.62%) and total soluble proline (23.20%) contents and superoxide dismutase activity (32.41%), compared to saline soil. Application of 2.5% (FYM + press mud), 5% press mud, and 10% compost significantly reduced MDA content (27%) and improved activities of catalase (38.64%) and peroxidase (48.29%), respectively, compared to saline soil, thus facilitated to alleviate oxidative stress in okra plants.
CONCLUSIONS
Using organic amendments (municipal solid waste compost, farmyard manure and press mud) was a cost-effective approach to improve salinity-induced osmotic and oxidative stress tolerance in okra plants.
Topics: Catalase; Antioxidants; Abelmoschus; Salinity; Manure; Solid Waste; Oxidative Stress; Soil; Peroxidases; Peroxidase; Superoxide Dismutase; Proline; Water; Sugars
PubMed: 37891469
DOI: 10.1186/s12870-023-04527-x -
Analytical and Bioanalytical Chemistry Oct 2023The use of peroxidase mimics has great potential for various real applications due to their strong catalytic activity. Herein, a facile strategy was proposed to directly...
The use of peroxidase mimics has great potential for various real applications due to their strong catalytic activity. Herein, a facile strategy was proposed to directly prepare CuO@g-CN by Cu-MOF derivatization and demonstrated its efficacy in constructing a multiple enzymatic cascade system by loading protein enzymes onto it. The resulting CuO@g-CN possessed high peroxidase-like activity, with a Michaelis constant (K) of 0.25 and 0.16 mM for HO and 3,3',5,5'-tetramethylbenzidine (TMB), respectively. Additionally, the high surface area of CuO@g-CN facilitated the loading of protein enzymes and maintained their activity over an extended period, expanding the potential applications of CuO@g-CN. To test its feasibility, CuO@g-CN/protein oxidase complex was prepared and used to sense the ripeness and freshness of fruits and meat, respectively. The mechanism relied on the fact that the ripeness of fruits increased and freshness of food decreased with the release of marked targets, such as glucose and xanthine, which could produce HO when digested by the corresponding oxidase. The peroxidase mimics of CuO@g-CN could then sensitively colorimetric detect HO in present of TMB. The obtained CuO@g-CN/oxidase complex exhibited an excellent linear response to glucose or xanthine in the range of 1.0-120 μmol/L or 8.0-350 μmol/L, respectively. Furthermore, accurate quantification of glucose and xanthine in real samples is achieved with spiked recoveries ranging from 80.2% to 120.0% and from 94.2% to 112.0%, respectively. Overall, this work demonstrates the potential of CuO@g-CN in various practical applications, such as food freshness detection.
Topics: Colorimetry; Hydrogen Peroxide; Glucose; Peroxidase; Peroxidases; Antioxidants; Xanthines
PubMed: 37468755
DOI: 10.1007/s00216-023-04844-y -
Analytical Chemistry Aug 2023Rational regulation of nanozyme activity can promote biochemical sensing by expanding sensing strategies and improving sensing performance, but the design of effective...
Rational regulation of nanozyme activity can promote biochemical sensing by expanding sensing strategies and improving sensing performance, but the design of effective regulatory strategies remains a challenge. Herein, a rapid DNA-encoded strategy was developed for the efficient regulation of Pt nanozyme activity. Interestingly, we found that the catalytic activity of Pt nanozymes was sequence-dependent, and its peroxidase activity was significantly enhanced only in the presence of T-rich sequences. Thus, different DNA sequences realized bidirectional regulation of Pt nanozyme peroxidase activity. Furthermore, the DNA-encoded strategy can effectively enhance the stability of Pt nanozymes at high temperatures, freezing, and long-term storage. Meanwhile, a series of studies demonstrated that the presence of DNA influenced the reduction degree of HPtCl precursors, which in turn affected the peroxidase activity of Pt nanozymes. As a proof of application, the sensor array based on the Pt nanozyme system showed superior performance in the accurate discrimination of antioxidants. This study obtained the regulation rules of DNA on Pt nanozymes, which provided theoretical guidance for the development of new sensing platforms and new ideas for the regulation of other nanozyme activities.
Topics: Antioxidants; DNA; Peroxidases; Peroxidase; Hydrogen Peroxide
PubMed: 37459119
DOI: 10.1021/acs.analchem.3c01564 -
Minerva Pediatrics Dec 2023There is a crucial balance between oxidant and antioxidant defense mechanisms. We aimed to evaluate the role of the balance of these systems in children with bloodstream...
BACKGROUND
There is a crucial balance between oxidant and antioxidant defense mechanisms. We aimed to evaluate the role of the balance of these systems in children with bloodstream infection.
METHODS
We analyzed prospectively oxidant and antioxidant stress parameters from serum samples of children with BSI besides demographic and clinical data of children. Serum levels of the total antioxidant status (TAS), total oxidant status (TOS), albumin, plasma thiol, disulphide, catalase (CAT), myeloperoxidase (MPO), ischemia-modified albumin (IMA) levels, ferroxidase and arylesterase (ARES) activity were evaluated in both patients and healthy controls.
RESULTS
A total of 113 children were evaluated, 50 of them had bacteremia and the remaining 63 were healthy subjects. The median TOS values were 18.5 µmol H
2 O2 /L and 13.1 µmol H2 O2 /L in patient and control groups, respectively with a statistically significant difference between groups. The mean serum IMA levels were 0.8±0.1 absorbance unit (ABSU) in patients and 0.5±0.09 ABSU in control, the difference between groups was statistically significant. The native thiol, total thiol levels and the disulphide levels were significantly lower in the patient group as compared with the control group. The myeloperoxidase level was 136 U/L in patients and 107 in controls with a statistically significant difference between groups.CONCLUSIONS
TOS, IMA, MPO, and particularly plasma thiols seem good candidates for accurate diagnosis of bacteremia in children.
Topics: Humans; Child; Antioxidants; Oxidants; Peroxidase; Biomarkers; Oxidative Stress; Serum Albumin; Disulfides; Sulfhydryl Compounds; Bacteremia
PubMed: 32881474
DOI: 10.23736/S2724-5276.20.05748-5 -
ACS Nano Oct 2023The abrogation of the self-adaptive redox evolution of tumors is promising for improving therapeutic outcomes. In this study, we designed a trimetallic alloy nanozyme...
The abrogation of the self-adaptive redox evolution of tumors is promising for improving therapeutic outcomes. In this study, we designed a trimetallic alloy nanozyme AuCuPt-PpIX (ACPP), which mimics up to five naturally occurring enzymes: glucose oxidase (GOD), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione peroxidase (GPx). Facilitated by these enzyme-mimicking traits, the constructed ACPP nanozymes can not only disrupt the established redox homeostasis in tumors through a series of enzymatic cascade reactions but also achieve cyclic regeneration of the relevant enzyme substrates. Density functional theory (DFT) calculations have theoretically explained the synergistic effect of multimetallic doping and the possible mechanism of enzymatic catalysis. The doped Cu and Pt sites are conducive to the adsorption, activation, and dissociation of reactant molecules, whereas the Au sites are conducive to desorption, which significantly improves catalytic efficiency via a synergistic effect. Additionally, ACPP nanozymes can improve the effect of protoporphyrin (PpIX)-enabled sonodynamic therapy (SDT) by alleviating hypoxia and initiating ferroptosis by inducing lipid peroxidation (LPO) and inhibiting GPX4 activity, thus achieving multimodal synergistic therapy. This study presents a typical paradigm to enable the use of multimetallic alloy nanozymes for the treatment of tumor cells with self-adaptive properties.
Topics: Humans; Neoplasms; Peroxidase; Peroxidases; Oxidation-Reduction; Glucose Oxidase; Catalysis
PubMed: 37811650
DOI: 10.1021/acsnano.3c06833 -
Rheumatology (Oxford, England) Jul 2023Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of life-threatening autoimmune diseases. Inhibitors of apoptosis proteins (IAPs) are a...
OBJECTIVES
Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of life-threatening autoimmune diseases. Inhibitors of apoptosis proteins (IAPs) are a class of molecules engaged in cell death and inflammation, interventions of which are proven effective in a number of inflammatory diseases. Here we tested whether targeting IAPs could ameliorate AAV and explored the potential mechanism.
METHODS
We collected 19 kidney specimens from patients with myeloperoxidase (MPO)-AAV to investigate the expression of IAPs. The IAP pan-inhibitor SM164 was used to treat the experimental autoimmune vasculitis (EAV) rat model of AAV. RNA sequencing of renal cortex and enrichment analysis were developed to interpret gene expression. Functional experiments were performed to investigate the role of SM164 on neutrophils and endothelial cells.
RESULTS
The expression of three IAPs (cIAP1, cIAP2 and XIAP) was upregulated in kidneys of AAV patients compared with normal controls. SM164 dramatically reduced renal injury in EAV rats. Transcriptomic analysis revealed prominent alterations in fatty acid oxidation and respiratory burst following SM164 treatment. Functional studies demonstrated that SM164 inhibited neutrophil activation induced by MPO-ANCA positive IgG or serum from MPO-AAV patients, and such inhibitory effect was abolished by gene silencing or pharmacological inhibition of fatty acid oxidation. SM164 also inhibited the adhesion of neutrophils to endothelial cells with little effect on the endothelial injury induced by serum from MPO-AAV patients.
CONCLUSION
Inhibition of IAPs with SM164 played a protective role in AAV through enhancing intracellular fatty acid oxidation in neutrophils.
Topics: Rats; Animals; Antibodies, Antineutrophil Cytoplasmic; Peroxidase; Endothelial Cells; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Neutrophils; Inhibitor of Apoptosis Proteins; Fatty Acids
PubMed: 36308438
DOI: 10.1093/rheumatology/keac621 -
Advanced Healthcare Materials Sep 2023Nanoenzymes have been widely explored for chemodynamic therapy (CDT) in cancer treatment. However, poor catalytic efficiency of nanoenzymes, especially in the tumor...
Nanoenzymes have been widely explored for chemodynamic therapy (CDT) in cancer treatment. However, poor catalytic efficiency of nanoenzymes, especially in the tumor microenvironment with insufficient H O and mild acidity, limits the effect of CDT. Herein, a new ultrathin RuCu nanosheet (NS) based nanoenzyme which has a large specific surface area and abundant channels and defects is developed. The RuCu NSs show superb catalytic efficiency for the oxidation of peroxidase substrate H O at a wide range of pH and their catalytic efficiency (k /K = 177.2 m s ) is about 14.9 times higher than that of the single-atom catalyst FeN P. Besides being an efficient nanozyme as peroxidase, the RuCu NSs possess other two enzyme activities, not only disproportionating superoxide anion to produce H O but also consuming glutathione to keep a high concentration of H O in the tumor microenvironment for Fenton reaction. With these advantages, the RuCu NSs exhibit good performance to kill cancer cells and inhibit tumor growth in mice, demonstrating a promising potential as new CDT reagent.
Topics: Animals; Mice; Peroxidase; Peroxidases; Catalysis; Glutathione; Superoxides; Tumor Microenvironment; Hydrogen Peroxide; Cell Line, Tumor; Neoplasms
PubMed: 37053081
DOI: 10.1002/adhm.202300490 -
New Biotechnology Nov 2023Lignin is the second most abundant natural polymer next to cellulose and by far the largest renewable source of aromatic compounds on the planet. Dye-decolourising... (Review)
Review
Lignin is the second most abundant natural polymer next to cellulose and by far the largest renewable source of aromatic compounds on the planet. Dye-decolourising peroxidases (DyPs) are biocatalysts with immense potential in lignocellulose biorefineries to valorize emerging lignin building blocks for environmentally friendly chemicals and materials. This work investigates the catalytic potential of the engineered PpDyP variant 6E10 for the oxidation of 24 syringyl, guaiacyl and hydroxybenzene lignin-phenolic derivatives. Variant 6E10 exhibited up to 100-fold higher oxidation rates at pH 8 for all the tested phenolic substrates compared to the wild-type enzyme and other acidic DyPs described in the literature. The main products of reactions were dimeric isomers with molecular weights of (2 × MW - 2 H). Their structure depends on the substitution pattern of the aromatic ring of substrates, i.e., of the coupling possibilities of the primarily formed radicals upon enzymatic oxidation. Among the dimers identified were syringaresinol, divanillin and diapocynin, important sources of structural scaffolds exploitable in medicinal chemistry, food additives and polymers.
Topics: Peroxidase; Lignin; Oxidoreductases; Peroxidases; Oxidation-Reduction; Phenols
PubMed: 36563877
DOI: 10.1016/j.nbt.2022.12.003