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Spectrochimica Acta. Part A, Molecular... Feb 2021Ficin has dual enzyme activity, i.e., protease and peroxidase-like activity. In some respects, its application is limited by the protease activity of ficin. Herein, we...
Enhancing the peroxidase activity and decreasing the protease activity of ficin with rational modification and its application to one-step colorimetric detection of glucose.
Ficin has dual enzyme activity, i.e., protease and peroxidase-like activity. In some respects, its application is limited by the protease activity of ficin. Herein, we used tris (2-carboxyethyl) phosphine hydrochloride (TCEP) to break the three pairs of disulfide bonds of ficin, and then blocked the free thiol groups with N-ethylmaleimide (NEM) to synthesize ficin-TN. The results showed that ficin-TN had increased peroxidase-like activity and reduced protease activity. According to this phenomenon, we have exploited a colorimetric method with high sensitivity and selectivity for the one-step detection of glucose. Comparing with ficin, ficin-TN has wider detection range (0.1-300 μM) and lower detection limit (88 nM), and our method is simpler and more timesaving than other two-step methods. Furthermore, the actual appliances of ficin-TN for glucose detection in human serum have been illustrated with satisfied result, suggesting that its promising utilization in various fields.
Topics: Colorimetry; Ficain; Glucose; Humans; Hydrogen Peroxide; Oxidation-Reduction; Peroxidase; Peroxidases
PubMed: 33126136
DOI: 10.1016/j.saa.2020.119091 -
Biomaterials Science Sep 2021Heme binds to a parallel-stranded G-quadruplex DNA to form a peroxidase-mimicking heme-DNAzyme. An interpolyelectrolyte complex between the heme-DNAzyme and a cationic...
Heme binds to a parallel-stranded G-quadruplex DNA to form a peroxidase-mimicking heme-DNAzyme. An interpolyelectrolyte complex between the heme-DNAzyme and a cationic copolymer possessing protonated amino groups was characterized and the peroxidase activity of the complex was evaluated to elucidate the effect of the polymer on the catalytic activity of the heme-DNAzyme. We found that the catalytic activity of the heme-DNAzyme is enhanced through the formation of the interpolyelectrolyte complex due to the general acid catalysis of protonated amino groups of the polymer, enhancing the formation of the iron(IV)oxo porphyrin π-cation radical intermediate known as Compound I. This finding indicates that the polymer with protonated amino groups can act as a cocatalyst for the heme-DNAzyme in the oxidation catalysis. We also found that the enhancement of the activity of the heme-DNAzyme by the polymer depends on the local heme environment such as the negative charge density in the proximity of the heme and substrate accessibility to the heme. These findings provide novel insights as to molecular design of the heme-DNAzyme for enhancing its catalytic activity.
Topics: Cations; DNA, Catalytic; Heme; Peroxidase; Peroxidases; Polymers
PubMed: 34346413
DOI: 10.1039/d1bm00949d -
Analytica Chimica Acta Dec 2022This report describes, for the first time, the coupling of UV-visible spectroscopy with multivariate curve resolution-alternative least-squares (MCR-ALS) algorithm to...
A colorimetric assay and MCR-ALS analysis of the peroxidase-like activity of poly (N-phenylglycine) functionalized with polyethylene glycol (PNPG-PEG) nanozyme for the determination of dopamine.
This report describes, for the first time, the coupling of UV-visible spectroscopy with multivariate curve resolution-alternative least-squares (MCR-ALS) algorithm to study peroxidase-like catalytic reaction of polyethylene glycol-functionalized poly (N-phenyl glycine) (PNPG-PEG) as an efficient and intrinsic peroxidase mimic activity (PMA) class of conducting organic polymer for selective detection of dopamine (DA) in the PNPG-PEG + TMB + HO reaction system. PNPG-PEG was produced by means of a chemical route using ammonium persulphate (APS) as an oxidant agent of N-phenyl glycine monomer. The chemical composition, morphology, and thermal behavior of PNPG-PEG were examined by various instrumental techniques. PNPG-PEG exhibited significant peroxidase-mimic activity to catalyze the oxidation 3,3',5,5'- tetramethylbenzidine (TMB) substrate to oxidized TMB (oxTMB). The qualitative and quantitative determination of the oxidized TMB can easily be detected by the naked-eye and the recorded UV-vis absorbance spectra at 652 nm, respectively. Owing to the superior peroxidase-mimic activity of PNPG-PEG, the colorimetric detection of dopamine was successfully achieved at pH 4.0. Under optimal conditions, acceptable linear dependency was recorded in the concentration range of 5.1-125.0 μM, with a limit of detection (LOD) and limit of quantification (LOQ) equal to 4.6 μM and 13.8 μM (S/N = 3), respectively. Furthermore, this colorimetric assay was successfully used for quantitative analysis of dopamine in fetal bovine serum (FBS) and horse serum (HS) samples with recoveries in the range of 97-105% and 100-122%, respectively. After resolving the bilinear data matrix using MCR-ALS, three chemical components were found for different concentrations and pure spectral profiles. Based on the resolved profiles, the presence of free, slightly penetrated, and majorly penetrated TMB molecules entering the polymeric structure can be easily detected using MCR-ALS as an available statical method without any complex separation instruments. This peroxidase mimetic nanozyme as a visual, simple, low-cost, sensitive, and reproducible colorimetric platform can provide great potential applications in the monitoring and diagnosis of dopamine-related diseases.
Topics: Horses; Animals; Colorimetry; Dopamine; Hydrogen Peroxide; Polyethylene Glycols; Peroxidase; Glycine; Peroxidases
PubMed: 36368835
DOI: 10.1016/j.aca.2022.340493 -
Analytica Chimica Acta Oct 2021Total Antioxidant Capacity (TAC) Assay plays an important role in evaluating the quality of antioxidant food and monitoring the oxidative stress level of human body. It...
Total Antioxidant Capacity (TAC) Assay plays an important role in evaluating the quality of antioxidant food and monitoring the oxidative stress level of human body. It is mainly achieved by measuring the contents of antioxidants such as AA, L-Cys and GSH, while TAC can be detected by using peroxidase-like activity of artificial nanoenzyme materials. In this work, the N-Doped, defect-rich N-MoSNFs nano-materials were used to build the nano enzyme, which has strong stability and high peroxidase-like activity. HO was detected because it can be catalyzed to generate the intermediate ·OH and make TMB appears blue. However, when HO, AA, L-Cys and GSH coexist in solution, due to the oxidation resistance of AA, L-Cys and GSH, they can competitively react with ·OH in solution or reduce TMB in oxidation state (oxTMB), which reduces the characteristic absorption of oxTMB, indirectly achieves the purpose of detecting AA, L-Cys and GSH, and finally realizes the determination of TAC, even in actual serum and saliva samples. At the same time, the N-MoS NFs/NH-MIL-53(Al)+OPD system is further constructed. Based on the fluorescence resonance energy transfer (FRET) between NH-MIL-53(Al) and oxidized OPD (oxOPD), the purpose of detecting TAC by fluorescence method was realized.
Topics: Antioxidants; Colorimetry; Humans; Hydrogen Peroxide; Molybdenum; Peroxidase; Peroxidases
PubMed: 34538313
DOI: 10.1016/j.aca.2021.338740 -
The Analyst May 2022Enzyme-based sensing platforms have undergone rapid development in the field of diagnosis and bioanalysis. Here we present a novel fluorescent artificial enzyme-based...
Enzyme-based sensing platforms have undergone rapid development in the field of diagnosis and bioanalysis. Here we present a novel fluorescent artificial enzyme-based detection strategy for L-cysteine (Cys) and HO by fabricating a series of Au-Ag bimetallic nanoparticles with peroxidase-like activity. Taking advantage of the enhanced performance of catalysts by optimizing the surface structure, the sensitive detection of Cys with an ultralow detection limit of 0.035 μM and accurate quantification in the range of 0.075-2 μM were achieved. It was revealed that the mechanism of the catalytic process on the Au-Ag surface follows the electron transfer mechanism rather than active species, that is the peroxidase-like catalysts work as electron transfer intermediates and the electron transfer efficiency will increase with the larger electron cloud density of active sites derived from the electronic synergistic effect between Au and Ag, contributing to the enhanced catalytic activity of peroxidase mimics. This finding could provide guidance for the structural design of high-activity peroxidase mimics.
Topics: Colorimetry; Coloring Agents; Cysteine; Fluorescence; Gold; Hydrogen Peroxide; Metal Nanoparticles; Peroxidase; Peroxidases
PubMed: 35404374
DOI: 10.1039/d1an02310a -
Small (Weinheim An Der Bergstrasse,... May 2023The external-stimulation-induced reactive-oxygen-species (ROS) generation has attracted increasing attention in therapeutics for malignant tumors. However, engineering a...
The external-stimulation-induced reactive-oxygen-species (ROS) generation has attracted increasing attention in therapeutics for malignant tumors. However, engineering a nanoplatform that integrates with efficient biocatalytic ROS generation, ultrasound-amplified ROS production, and simultaneous relief of tumor hypoxia is still a great challenge. Here, we create new semiconducting titanate-supported Ru clusterzymes (RuNC/BTO) for ultrasound-amplified biocatalytic tumor nanotherapies. The morphology and chemical/electronic structure analysis prove that the biocatalyst consists of Ru nanoclusters that are tightly stabilized by Ru-O coordination on BaTiO . The peroxidase (POD)- and halogenperoxidase-like biocatalysis reveals that the RuNC/BTO can produce abundant •O radicals. Notably, the RuNC/BTO exhibits the highest turnover number (63.29 × 10 s ) among the state-of-the-art POD-mimics. Moreover, the catalase-like activity of the RuNC/BTO facilitates the decomposition of H O to produce O for relieving the hypoxia of the tumor and amplifying the ROS level via ultrasound irradiation. Finally, the systematic cellular and animal experiments have validated that the multi-modal strategy presents superior tumor cell-killing effects and suppression abilities. We believe that this work will offer an effective clusterzyme that can adapt to the tumor microenvironment-specific catalytic therapy and also provide a new pathway for engineering high-performance ROS production materials across broad therapeutics and biomedical fields.
Topics: Animals; Biocatalysis; Reactive Oxygen Species; Ruthenium; Neoplasms; Ultrasonography; Peroxidase; Peroxidases; Coloring Agents; Oxygen; Tumor Microenvironment; Cell Line, Tumor
PubMed: 36765452
DOI: 10.1002/smll.202206911 -
The Science of the Total Environment Jan 2023A large amount of terrigenous organic matter (TOM) is constantly transported to the deep sea. However, relatively little is known about the microbial mineralization of...
A large amount of terrigenous organic matter (TOM) is constantly transported to the deep sea. However, relatively little is known about the microbial mineralization of TOM therein. Our recent in situ enrichment experiments revealed that Vibrio is especially enriched as one of the predominant taxa in the cultures amended with natural plant materials in the deep sea. Yet their role in the mineralization of plant-derived TOM in the deep sea remains largely unknown. Here we isolated Vibrio strains representing dominant members of the enrichments and verified their potential to degrade lignin and xylan. The isolated strains were closely related to Vibrio harveyi, V. alginolyticus, V. diabolicus, and V. parahaemolyticus. Extracellular enzyme assays, and genome and transcriptome analyses revealed diverse peroxidases, including lignin peroxidase (LiP), catalase-peroxidase (KatG), and decolorizing peroxidase (DyP), which played an important role in the depolymerization and oxidation of lignin. Superoxide dismutase was found to likely promote lignin oxidation by supplying HO to LiP, DyP, and KatG. Interestingly, these deep-sea Vibrio strains could oxidize lignin and hydrolyze xylan not only through aerobic pathway, but also through anaerobic pathway. Genome analysis revealed multiple anaerobic respiratory mechanisms, including the reductions of nitrate, arsenate, tetrathionate, and dimethyl sulfoxide. The strains showed the potential to anaerobically reduce sulfite and metal oxides of iron and manganese, in contrast the non-deep-sea Vibrio strains were not retrieved of genes involved in reduction of metal oxides. This is the first report about the lignin oxidation mechanisms in Vibrio and their role in TOM mineralization in anoxic and oxic environments of the marginal sea.
Topics: Peroxidase; Lignin; Xylans; Hydrogen Peroxide; Vibrio; Oxidation-Reduction; Oxides
PubMed: 36113801
DOI: 10.1016/j.scitotenv.2022.158714 -
Analytical Chemistry Jul 2023Nanozymes are functional nanomaterials with enzyme-like activities, which have good stability and specific nanoscale properties. Among them, peroxidase-like (POD-like)...
Nanozymes are functional nanomaterials with enzyme-like activities, which have good stability and specific nanoscale properties. Among them, peroxidase-like (POD-like) nanozymes with two substrates are the biggest chunk and have been widely applied in biomedical and environmental fields. Maximum velocity () is an essential kinetic parameter, accurate measurements of which can help in activity comparisons, mechanism studies, and nanozyme improvements. At present, the standardized assay determines the catalytic kinetics of POD-like nanozymes by a single fitting based on the Michaelis-Menten equation. However, the true cannot be confirmed by this method due to the test condition that the concentration of a fixed substrate is finite. Here, a double fitting method to determine the intrinsic of POD-like nanozymes is presented, which breaks through the limited concentration of the fixed substrate by an additional Michaelis-Menten fitting. Furthermore, a comparison of the among five typical POD-like nanozymes validates the accuracy and feasibility of our method. This work provides a credible method to determine the true of POD-like nanozymes, helping in activity comparisons and facilitating studies on the mechanism and development of POD-like nanozymes.
Topics: Peroxidase; Peroxidases; Nanostructures; Catalysis; Kinetics; Coloring Agents
PubMed: 37341651
DOI: 10.1021/acs.analchem.3c01830 -
Journal of Applied Microbiology Dec 2020The aim of the study is to investigate the efficiency of Geotrichum candidum in the decolourization and mineralization of synthetic azo dyes.
AIM
The aim of the study is to investigate the efficiency of Geotrichum candidum in the decolourization and mineralization of synthetic azo dyes.
METHODS AND RESULTS
It includes screening of enzymes from G. candidum and its optimization, followed by decolourization and mineralization studies. Decolourization was observed to be maximum in methyl orange (94·6%) followed by Congo red (85%), trypan blue (70·4%) and Eriochrome Black T (55·6%) in 48 h, suggesting the plausible degradation of the azo dyes by G. candidum. The enzyme activity study showed that DyP-type peroxidase has highest activity of 900 mU ml compared to that of laccase (405 mU ml ) and lignin peroxidase (LiP) (324 mU ml ) at optimized pH (6) and temperature (35°C). Moreover, the rate of decolourization was found to be directly proportional to the production of laccase and LiP, unlike DyP-type peroxidase. Furthermore, mineralization study demonstrated reduction in aromatic amines, showing 20% mineralization of methyl orange.
CONCLUSION
Geotrichum candidum with its enzyme system is able to efficiently decolourize and mineralize the experimental azo dyes.
SIGNIFICANCE AND IMPACT OF THE STUDY
The efficient decolourization and mineralization of azo dyes makes G. candidum a promising alternative in the treatment of textile effluent contaminated with azo dyes.
Topics: Azo Compounds; Biodegradation, Environmental; Coloring Agents; Fungal Proteins; Geotrichum; Laccase; Peroxidase; Peroxidases; Textiles; Water Decolorization
PubMed: 32491245
DOI: 10.1111/jam.14731 -
The Analyst Nov 2022Developing carbon-based materials with high catalytic performance and sensitivity has significance in low-cost and highly efficient nanozymes. Herein, for the first...
Developing carbon-based materials with high catalytic performance and sensitivity has significance in low-cost and highly efficient nanozymes. Herein, for the first time, Cu,N-codoped hollow carbon nanospheres (CuNHCNs) with highly active Cu-Nx sites were successfully assembled through a template-free strategy, in which Cu-poly(-phenylenediamine) (Cu-PmPD) nanospheres were utilized as the source of Cu, N and C. Benefiting from the synergistic effect of the hollow spherical structure and optimized composition, the CuNHCN exhibits high affinity for 3,3',5,5'-tetramethylbenzidine and HO with 0.0655 mM and 0.918 mM, respectively, which are superior to those of HRP and most metal-based nanozymes. Moreover, by employing glucose and ascorbic acid (AA) as biomolecule models, a CuNHCN-based colorimetric detection platform is developed. The CuNHCN exhibits superior peroxidase mimicking activity and sensitivity in detecting glucose and AA with a detection limit of 0.187 μM and 68.9 nM (S/N = 3), respectively. Also, the colorimetric detection based on the CuNHCN towards glucose and AA in human serum presents superior practicability and accuracy. The assay provides a new avenue for designing and fabricating low-cost peroxidase nanozymes with high performance in bioassays.
Topics: Humans; Carbon; Colorimetry; Glucose; Hydrogen Peroxide; Nanospheres; Peroxidase; Peroxidases; Copper; Nitrogen
PubMed: 36314762
DOI: 10.1039/d2an01488b