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1.
J Am Chem Soc ; 146(19): 13247-13257, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38701006

ABSTRACT

Horseradish peroxidase (HRP) is an enzyme that oxidizes pollutants from wastewater. A previous report indicated that peroxidases can have an enhancement in initial enzymatic activity in an aqueous solution of 0.26 M 1-ethyl-3-methylimidazolium ethyl sulfate ([EMIm][EtSO4]) at neutral pH. However, the atomistic details remain elusive. In the enzymatic landscape of HRP, compound II (Cpd II) plays a key role and involves a histidine (H42) residue. Cpd II exists as oxoferryl (2a) or hydroxoferryl (2b(FeIV)) forms, where 2a is the predominantly observed form in experimental studies. Intriguingly, the ferric 2b(FeIII) form seen in synthetic complexes has not been observed in HRP. Here, we have investigated the structure and dynamics of HRP in pure water and aqueous [EMIm][EtSO4] (0.26 M), as well as the reaction mechanism of 2a to 2b conversion using polarizable molecular dynamics (MD) simulations and quantum mechanics/molecular mechanics (QM/MM) calculations. When HRP is solvated in aq [EMIm][EtSO4], the catalytic water displaces, and H42 directly orients over the ferryl moiety, allowing a direct proton transfer (PT) with a significant energy barrier reduction. Conversely, in neat water, the reaction of 2a to 2b follows the previously reported mechanism. We further investigated the deprotonated form of H42. Analysis of the electric fields at the active site indicates that the aq [EMIm][EtSO4] medium facilitates the reaction by providing a more favorable environment compared with the system solvated in neat water. Overall, the atomic level supports the previous experimental observations and underscores the importance of favorable electric fields in the active site to promote catalysis.


Subject(s)
Horseradish Peroxidase , Ionic Liquids , Molecular Dynamics Simulation , Horseradish Peroxidase/chemistry , Horseradish Peroxidase/metabolism , Ionic Liquids/chemistry , Imidazoles/chemistry , Quantum Theory , Solutions , Water/chemistry
2.
Sci Rep ; 14(1): 11442, 2024 05 20.
Article in English | MEDLINE | ID: mdl-38769440

ABSTRACT

The global supply of fluoropolymers and fluorinated solvents is decreasing due to environmental concerns regarding polyfluoroalkyl substances. CYTOP has been used for decades primarily as a component of a femtoliter chamber array for digital bioanalysis; however, its supply has recently become scarce, increasing the urgency of fabricating a femtoliter chamber array using alternative materials. In this study, we investigated the feasibility of fabricating a femtoliter chamber array using four types of fluoropolymers in stable supply as candidate substitutes and verified their applicability for digital bioanalysis. Among these candidates, Fluorine Sealant emerged as a viable option for fabricating femtoliter chamber arrays using a conventional photolithography process. To validate its efficacy, we performed various digital bioanalysis using FP-A-based chamber arrays with model enzymes such as CRISPR-Cas, horseradish peroxidase, and ß-galactosidase. The results demonstrated the similar performance to that of CYTOP, highlighting the broader utility of FP-A in digital bioanalysis. Our findings underscore the potential of FP-A to enhance the versatility of digital bioanalysis and foster the ongoing advancement of innovative diagnostic technologies.


Subject(s)
Polymers , Polymers/chemistry , Horseradish Peroxidase/metabolism , Horseradish Peroxidase/chemistry , beta-Galactosidase/metabolism
3.
ACS Appl Bio Mater ; 7(5): 3506-3514, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38696441

ABSTRACT

Horseradish peroxidase (HRP)-mediated hydrogelation, caused by the cross-linking of phenolic groups in polymers in the presence of hydrogen peroxide (H2O2), is an effective route for bioink solidification in 3D bioprinting. Sugar beet pectin (SBP) naturally has cross-linkable phenols through the enzymatic reaction. Therefore, chemical modifications are not required, unlike the various polymers that have been used in the enzymatic cross-linking system. In this study, we report the application of SBP in extrusion-based bioprinting including HRP-mediated bioink solidification. In this system, H2O2 necessary for the solidification of inks is supplied in the gas phase. Cell-laden liver lobule-like constructs could be fabricated using bioinks consisting of 10 U/mL HRP, 4.0 and 6.0 w/v% SBP, and 6.0 × 106 cells/mL human hepatoblastoma (HepG2) cells exposed to air containing 16 ppm of H2O2 concurrently during printing and 10 min postprinting. The HepG2 cells enclosed in the printed constructs maintained their viability, metabolic activity, and hepatic functions from day 1 to day 7 of the culture, which indicates the cytocompatibility of this system. Taken together, this result demonstrates the potential of SBP and HRP cross-linking systems for 3D bioprinting, which can be applied in tissue engineering applications.


Subject(s)
Beta vulgaris , Biocompatible Materials , Bioprinting , Horseradish Peroxidase , Materials Testing , Pectins , Printing, Three-Dimensional , Horseradish Peroxidase/metabolism , Horseradish Peroxidase/chemistry , Beta vulgaris/chemistry , Humans , Pectins/chemistry , Hep G2 Cells , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Biocompatible Materials/chemical synthesis , Hydrogen Peroxide/chemistry , Particle Size , Cell Survival/drug effects , Cross-Linking Reagents/chemistry , Cross-Linking Reagents/chemical synthesis , Tissue Engineering
4.
Biomacromolecules ; 25(5): 3055-3062, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38693874

ABSTRACT

Polymersomes, nanosized polymeric vesicles, have attracted significant interest in the areas of artificial cells and nanomedicine. Given their size, their visualization via confocal microscopy techniques is often achieved through the physical incorporation of fluorescent dyes, which however present challenges due to potential leaching. A promising alternative is the incorporation of molecules with aggregation-induced emission (AIE) behavior that are capable of fluorescing exclusively in their assembled state. Here, we report on the use of AIE polymersomes as artificial organelles, which are capable of undertaking enzymatic reactions in vitro. The ability of our polymersome-based artificial organelles to provide additional functionality to living cells was evaluated by encapsulating catalytic enzymes such as a combination of glucose oxidase/horseradish peroxidase (GOx/HRP) or ß-galactosidase (ß-gal). Via the additional incorporation of a pyridinium functionality, not only the cellular uptake is improved at low concentrations but also our platform's potential to specifically target mitochondria expands.


Subject(s)
Glucose Oxidase , Horseradish Peroxidase , beta-Galactosidase , Glucose Oxidase/chemistry , Humans , beta-Galactosidase/chemistry , beta-Galactosidase/metabolism , Horseradish Peroxidase/chemistry , Horseradish Peroxidase/metabolism , Organelles/metabolism , Fluorescent Dyes/chemistry , Polymers/chemistry , Fluorescence , HeLa Cells , Mitochondria/metabolism
5.
Anal Chem ; 96(16): 6337-6346, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38613479

ABSTRACT

The arsM gene is a critical biomarker for the potential risk of arsenic exposure in paddy soil. However, on-site screening of arsM is limited by the lack of high-throughput point-of-use (POU) methods. Here, a multiplex CRISPR/Cas12a microfluidic paper-based analytical device (µPAD) was constructed for the high-throughput POU analysis of arsM, with cascade amplification driven by coupling crRNA-enhanced Cas12a and horseradish peroxidase (HRP)-modified probes. First, seven crRNAs were designed to recognize arsM, and their LODs and background signal intensities were evaluated. Next, a step-by-step iterative approach was utilized to develop and optimize coupling systems, which improved the sensitivity 32 times and eliminated background signal interference. Then, ssDNA reporters modified with HRP were introduced to further lower the LOD to 16 fM, and the assay results were visible to the naked eye. A multiplex channel microfluidic paper-based chip was developed for the reaction integration and simultaneous detection of 32 samples and generated a recovery rate between 87.70 and 114.05%, simplifying the pretreatment procedures and achieving high-throughput POU analysis. Finally, arsM in Wanshan paddy soil was screened on site, and the arsM abundance ranged from 1.05 × 106 to 6.49 × 107 copies/g; this result was not affected by the environmental indicators detected in the study. Thus, a coupling crRNA-based cascade amplification method for analyzing arsM was constructed, and a microfluidic device was developed that contains many more channels than previous paper chips, greatly improving the analytical performance in paddy soil samples and providing a promising tool for the on-site screening of arsM at large scales.


Subject(s)
Soil , Soil/chemistry , Horseradish Peroxidase/metabolism , Horseradish Peroxidase/chemistry , CRISPR-Cas Systems , Oryza/chemistry , Soil Pollutants/analysis , Lab-On-A-Chip Devices , Endodeoxyribonucleases/metabolism , Endodeoxyribonucleases/chemistry , High-Throughput Screening Assays/methods , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , CRISPR-Associated Proteins/metabolism , Limit of Detection , Nucleic Acid Amplification Techniques/methods
6.
Anal Sci ; 40(5): 951-958, 2024 May.
Article in English | MEDLINE | ID: mdl-38598048

ABSTRACT

Daily monitoring of serum uric acid levels is very important to provide appropriate treatment according to the constitution and lifestyle of individual hyperuricemic patients. We have developed a suspension-based assay to measure uric acid by adding a sample solution to the suspension containing micro-sized particles immobilized on uricase and horseradish peroxidase (HRP). In the proposed method, the mediator reaction of uricase, HRP, and uric acid produces resorufin from Amplex red. This resorufin is adsorbed onto enzyme-immobilized micro-sized particles simultaneously with its production, resulting in the red color of the micro-sized particles. The concentration of resorufin on the small surface area of the microscopic particles achieves a colorimetric analysis of uric acid with superior visibility. In addition, ethanol-induced desorption of resorufin allowed quantitative measurement of uric acid using a 96-well fluorescent microplate reader. The limit of detection (3σ) and RSD (n = 3) were estimated to be 2.2 × 10-2 µg/mL and ≤ 12.1%, respectively. This approach could also be applied to a portable fluorometer.


Subject(s)
Colorimetry , Enzymes, Immobilized , Fluorometry , Horseradish Peroxidase , Urate Oxidase , Uric Acid , Uric Acid/blood , Uric Acid/chemistry , Uric Acid/analysis , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Urate Oxidase/chemistry , Urate Oxidase/metabolism , Horseradish Peroxidase/chemistry , Horseradish Peroxidase/metabolism , Particle Size , Humans , Suspensions , Oxazines/chemistry
7.
Chemosphere ; 358: 142145, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38670514

ABSTRACT

This research reported on the immobilization of environmentally friendly enzymes, such as horseradish peroxidase (HRP) and laccase (L), along with the hydrophilic zwitterionic compound l-DOPA on nano-filtration (NF) membranes. This approach introduced biocatalytic membranes, leveraging combined effects between membranes and enzymes. The aim was to systematically assess the efficacy of the enzymatic modified membrane (HRP-NF) in degrading colors in the wastewater, as well as enhancing the membrane resistance toward organic fouling. The enzymatic immobilized membrane demonstrated 96.3 ± 1.8% to 96.6 ± 1.9% removal of colors, and 65.2 ± 1.3% to 67.2 ± 1.3% removal of TOC. This result was underpinned by the insights obtained from the radical scavenger coumarin, which was employed to trap and confirm the formation of PRs through the reaction of enzymes and H2O2. Furthermore, membranes modified with enzymes exhibited significantly improved antifouling properties. The HRP-NF membrane experienced an 8% decline in flux, while the co-immobilized HRP-L-NF membrane demonstrated as low as 6% flux decline, contributed by the synergistic effect of increased hydrophilicity and biocatalytic effects. These findings confirmed that the immobilized enzymatic surface has added function of degrading contaminants in addition to separation function of nanofiltration membrane. These l-DOPA-immobilized enzymatic membranes offered a promising hybrid biocatalytic membrane to eliminate dyes and mitigate membrane fouling, which can be applied in many industrial and domestic water and wastewater treatment.


Subject(s)
Biocatalysis , Enzymes, Immobilized , Horseradish Peroxidase , Laccase , Membranes, Artificial , Wastewater , Water Pollutants, Chemical , Laccase/metabolism , Laccase/chemistry , Horseradish Peroxidase/metabolism , Horseradish Peroxidase/chemistry , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Wastewater/chemistry , Water Pollutants, Chemical/chemistry , Biofouling/prevention & control , Hydrophobic and Hydrophilic Interactions , Filtration/methods , Levodopa/chemistry , Water Purification/methods , Hydrogen Peroxide/chemistry , Waste Disposal, Fluid/methods
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 315: 124236, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38615415

ABSTRACT

In this work, a colorimetric aptasensor based on magnetic beads (MBs), gold nanoparticles (AuNPs) and Horseradish Peroxidase (HRP) was prepared for the detection of mucin 1 (MUC1). Complementary DNA of the MUC1 aptamer (Apt) immobilized on the MBs was combined with the prepared AuNPs-Apt-HRP complex (AuNPs@Apt-HRP). In the presence of MUC1, it specifically bound to Apt, resulting in the detachment of gold nanoparticles from the MBs. After magnetic separation, AuNPs@Apt-HRP was separated into the supernatant and reacted with 3,3',5,5'-Tetramethylbenzidine (TMB) to produce color reaction from colorless to blue. The linear range of MUC1 was from 75 to 500 µg/mL (R2 = 0.9878), and the detection limit was 41.95 µg/mL. The recovery rate of MUC1 in human serum was 99.18 %∼101.15 %. This method is simple and convenient. Moreover, it does not require complex and expensive equipment for detection of MUC1. It provides value for the development of MUC1 colorimetric sensors and a promising strategy for the determination of MUC1 in clinical diagnosis.


Subject(s)
Aptamers, Nucleotide , Benzidines , Biosensing Techniques , Colorimetry , Gold , Limit of Detection , Metal Nanoparticles , Mucin-1 , Mucin-1/analysis , Mucin-1/blood , Colorimetry/methods , Gold/chemistry , Aptamers, Nucleotide/chemistry , Metal Nanoparticles/chemistry , Humans , Biosensing Techniques/methods , Horseradish Peroxidase/chemistry , Horseradish Peroxidase/metabolism
9.
Anal Chem ; 96(18): 7281-7288, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38663032

ABSTRACT

Single-cell spatial proteomic analysis holds great promise to advance our understanding of the composition, organization, interaction, and function of the various cell types in complex biological systems. However, the current multiplexed protein imaging technologies suffer from low detection sensitivity, limited multiplexing capacity, or are technically demanding. To tackle these issues, here, we report the development of a highly sensitive and multiplexed in situ protein profiling method using off-the-shelf antibodies. In this approach, the protein targets are stained with horseradish peroxidase (HRP) conjugated antibodies and cleavable fluorophores via click chemistry. Through repeated cycles of target staining, fluorescence imaging, and fluorophore cleavage, many proteins can be profiled in single cells in situ. Applying this approach, we successfully quantified 28 different proteins in human formalin-fixed paraffin-embedded (FFPE) tonsil tissue, which represents the highest multiplexing capacity among the tyramide signal amplification (TSA) methods. Based on their unique protein expression patterns and their microenvironment, ∼820,000 cells in the tissue are classified into distinct cell clusters. We also explored the cell-cell interactions between these varied cell clusters and observed that different subregions of the tissue are composed of cells from specific clusters.


Subject(s)
Click Chemistry , Fluorescent Dyes , Palatine Tonsil , Humans , Fluorescent Dyes/chemistry , Palatine Tonsil/cytology , Palatine Tonsil/chemistry , Palatine Tonsil/metabolism , Single-Cell Analysis , Proteins/analysis , Proteins/chemistry , Proteins/metabolism , Proteomics/methods , Horseradish Peroxidase/chemistry , Horseradish Peroxidase/metabolism , Optical Imaging , Paraffin Embedding
10.
J Mater Chem B ; 12(16): 3996-4003, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38563677

ABSTRACT

Encapsulation of enzymes within porous materials has shown great promise for protecting enzymes from denaturation, increasing their tolerance to harsh environments and promoting their industrialization. However, controlling the conformational freedom of the encapsulated enzymes to enhance their catalytic performance remains a great challenge. To address this issue, herein, following immobilization of GOx and HRP on a thermo-responsive porous poly(styrene-maleic-anhydride-N-isopropylacrylamide) (PSMN) membrane, a GOx-HRP@PSMN@HZIF-8 composite was fabricated by encapsulating GOx-HRP@PSMN in hollow ZIF-8 (HZIF-8) with liposome (L) as the sacrificial template. The improved conformational freedom for enzymes arising from the hollow cavity formed in ZIF-8 through the removal of L enhanced the mass transfer and dramatically promoted the catalytic activity of the composite. Interestingly, at high temperature, the coiled PN moiety in PSMN provided the confinement effect for GOx-HRP, which also significantly boosted the catalytic performance of the composites. Compared to the maximum catalytic reaction rates (Vmax) of GOx-HRP@PSMN@LZIF-8, the free enzyme and GOx-HRP@ZIF-8, the Vmax of the GOx-HRP@PSMN@HZIF-8 composite exhibited an impressive 17.8-fold, 10.8-fold and 6.0-fold enhancement at 37 °C, respectively. The proposed composites successfully demonstrated their potential as catalytic platforms for the colorimetric detection of glucose in a cascade reaction. This study paves a new way for overcoming the current limitations of immobilizing enzymes in porous materials and the use of smart polymers for the potential fabrication of enzyme@polymer@MOF composites with tunable conformational freedom and confinement effect.


Subject(s)
Enzymes, Immobilized , Glucose Oxidase , Metal-Organic Frameworks , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Metal-Organic Frameworks/chemistry , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Horseradish Peroxidase/chemistry , Horseradish Peroxidase/metabolism , Polymers/chemistry , Surface Properties , Porosity , Particle Size , Catalysis , Biocatalysis , Polystyrenes/chemistry
11.
Mikrochim Acta ; 191(4): 209, 2024 03 19.
Article in English | MEDLINE | ID: mdl-38499840

ABSTRACT

A novel colorimetric platform was designed for the determination of S. aureus by utilizing a dual-recognition strategy, where wheat germ agglutinin (WGA)-functionalized magnetic beads were served as separation elements to capture and enrich S. aureus efficiently from the matrix. Horseradish peroxidase (HRP) labeled chicken anti-protein A IgY (HRP-IgY) was used to label the captured S. aureus. A chicken IgY was introduced as a signal tracer to bind with staphylococcal protein A (SPA) on the surface of S. aureus, which can circumvent the interference from protein G-producing Streptococcus. Subsequently, the colorimetric signal was achieved by an HRP-catalyzed reaction, which was amplified by HRP-IgY bound by approximately 80,000 SPA molecules on one S. aureus. The entire detection process could be accomplished within 90 min. Under optimal conditions, the linear response of different S. aureus concentrations ranged from 7.8 × 102 to 2.0 × 105 CFU/mL and the limit of detection reached down to 3.9 × 102 CFU/mL. Some common non-target bacteria yielded negative results, indicating the excellent specificity of the method. The developed strategy was successfully applied to the determination of S. aureus in various types of samples with satisfactory recoveries. Therefore, the novel dual-recognition strategy possessed the advantages of high sensitivity, specificity, and low cost and exhibited considerable potential as a promising tool to defend public health.


Subject(s)
Staphylococcal Infections , Staphylococcus aureus , Humans , Wheat Germ Agglutinins , Colorimetry/methods , Immunoglobulins , Staphylococcal Infections/diagnosis , Staphylococcal Infections/microbiology , Horseradish Peroxidase/metabolism
12.
J Am Chem Soc ; 146(12): 8228-8241, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38471004

ABSTRACT

It remains a tremendous challenge to explore effective therapeutic modalities against neuroblastoma, a lethal cancer of the sympathetic nervous system with poor prognosis and disappointing treatment outcomes. Considering the limitations of conventional treatment modalities and the intrinsic vulnerability of neuroblastoma, we herein develop a pioneering sequential catalytic therapeutic system that utilizes lactate oxidase (LOx)/horseradish peroxidase (HRP)-loaded amorphous zinc metal-organic framework, named LOx/HRP-aZIF, in combination with a 3-indole-acetic acid (IAA) prodrug. On the basis of abnormal lactate accumulation that occurs in the tumor microenvironment, the cascade reaction of LOx and HRP consumes endogenous glutathione and a reduced form of nicotinamide adenine dinucleotide to achieve the first stage of killing cancer cells via antioxidative incapacitation and electron transport chain interference. Furthermore, the generation of reactive oxygen species induced by HRP and IAA through bioorthogonal catalysis promotes ferritin degradation and lipid peroxidation, ultimately provoking self-enhanced ferroptosis with positive feedback by initiating an endogenous Fenton reaction. This work highlights the superiority of the natural enzyme-dependent cascade and bioorthogonal catalytic reaction, offering a paradigm for synergistically enzyme-based metabolism-ferroptosis anticancer therapy.


Subject(s)
Ferroptosis , Neoplasms , Neuroblastoma , Humans , Antioxidants/pharmacology , Horseradish Peroxidase/metabolism , Catalysis , Cell Line, Tumor , Tumor Microenvironment
13.
Sci Rep ; 14(1): 1362, 2024 01 16.
Article in English | MEDLINE | ID: mdl-38228654

ABSTRACT

Chia gum's molecular structure with distinctive properties as well as the alginate-based hydrogel's three-dimensionally cross-linked structure can provide a potent matrix for immobilization of enzyme. Herein, chia gum (CG)/alginate (A)-polymeric complex was synthesized and employed as a support material for the immobilization of horseradish peroxidase (HRP). HRP was successfully immobilized on the developed ACG-polymeric support, and the highest immobilization recovery (75%) was observed at 1.0% CG and 2% A, pH 7.0, and 50 units of the enzyme. The structure, morphology, and thermal properties of the prepared ACG-HRP were demonstrated using Fourier Transform Infrared (FTIR), Scanning Electron Microscope, and Thermogravimetric (TGA) analyses. ACG-HRP showed a good reusability (60%) over ten reuses. The immobilized ACG-HRP displayed an acidic pH optimum (6.0), a higher temperature optimum (50 °C), and improved thermal stability (30-50 °C) compared to the soluble HRP at pH 7.0, 40 °C and (30-40 °C), respectively. ACG-HRP has a lower affinity for hydrogen peroxide (H2O2) and guaiacol and a higher oxidizing affinity for a number of phenolic substrates. The ACG-HRP demonstrated greater resistance to heavy metals, isopropanol, urea, Triton X-100, and urea, as well as improved efficiency for eliminating phenol and p-chlorophenol. The developed ACG-polymeric support provided improved enzyme properties, allowed the reuse of the immobilized HRP in 10 cycles, and made it promising for several biotechnological applications.


Subject(s)
Enzymes, Immobilized , Polymers , Enzymes, Immobilized/chemistry , Enzyme Stability , Temperature , Horseradish Peroxidase/metabolism , Hydrogen Peroxide , Phenol , Urea , Hydrogen-Ion Concentration
14.
Cold Spring Harb Protoc ; 2024(2): pdb.prot107805, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-36922000

ABSTRACT

Precisely where and when a given gene is expressed is crucial for our understanding of developmental and cell biology but determining this is often constrained by detection limits. Here, we describe a technique for visualization of low-copy mRNA in Nothobranchius furzeri embryos using tyramide signal amplification (TSA). In this protocol, an anti-sense digoxigenin-labeled RNA probe is hybridized to mRNA in situ. Anti-digoxigenin antibodies conjugated to horseradish peroxidase (POD) are then bound to the probe and reacted with fluorescently labeled tyramide. Combining this method with a counterstain, such as DAPI, allows for the detection of mRNA at a single-cell resolution.


Subject(s)
Killifishes , RNA, Antisense , In Situ Hybridization, Fluorescence/methods , RNA, Messenger/metabolism , Horseradish Peroxidase/metabolism
15.
Chemosphere ; 349: 140803, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38040249

ABSTRACT

The deteriorating environmental conditions due to increasing emerging recalcitrant pollutants raised a severe concern for its remediation. In this study, we have reported antibiotic degradation using free and immobilized HRP. The functionalized cellulose support was utilized for efficient immobilization of HRP. Approximately 13.32 ± 0.52 mg/g enzyme loading was achieved with >99% immobilization efficiency. The higher percentage of immobilization is attributed to the higher surface area and carboxylic groups on the support. The kinetic parameter of immobilized enzymes was Km = 2.99 mM/L for CNF-CA@HRP, which is 3.5-fold more than the Michaelis constant (Km = 0.84794 mM/L) for free HRP. The Vmax of CNF-CA@HRP bioconjugate was 2.36072 mM/min and 0.558254 mM/min for free HRP. The highest degradation of 50, 54.3, and 97% were achieved with enzymatic, sonolysis, and sono-enzymatic with CNF-CA@HRP bioconjugate, respectively. The reaction kinetics analysis revealed that applying ultrasound with an enzymatic process could enhance the reaction rate by 2.7-8.4 times compared to the conventional enzymatic process. Also, ultrasound changes the reaction from diffusion mode to the kinetic regime with a more oriented and fruitful collision between the molecules. The thermodynamic analysis suggested that the system was endothermic and spontaneous. While LC-MS analysis and OTC's degradation mechanism suggest, it mainly involves hydroxylation, secondary alcohol oxidation, dehydration, and decarbonylation. Additionally, the toxicity test confirmed that the sono-enzymatic process helps toward achieving complete mineralization. Further, the reusability of bioconjugate shows that immobilized enzymes are more efficient than the free enzyme.


Subject(s)
Cellulose , Enzymes, Immobilized , Enzymes, Immobilized/metabolism , Enzyme Stability , Biodegradation, Environmental , Anti-Bacterial Agents , Horseradish Peroxidase/metabolism , Temperature , Thermodynamics , Kinetics , Hydrogen-Ion Concentration
16.
J Inorg Biochem ; 250: 112394, 2024 01.
Article in English | MEDLINE | ID: mdl-37864880

ABSTRACT

Bio-enzymes have the advantages of strong substrate specificity, high catalytic efficiency, and minimal toxic side effects, making them promising drugs in cancer therapy. However, the poor stability and cellular penetrability of uncoated protein in the physiological environment severely restricts the direct application of Bio-enzyme. To address it, we report a metal-organic framework (MOF), Hf-DBA (H2DBA, biphenyl carboxylic acid ligands). The morphology of the Hf-DBA was revealed by TEM and the diameter was in the range of 200 to 350 nm. Hf-DBA acted a carrier for intracellular delivery and protection of horseradish peroxidase (HRP). The prepared HRP@Hf-DBA can catalyze the excess H2O2 in the tumor cells to generation of •OH for chemodynamic therapy (CDT). Compared with free HRP, the catalytic activity of HRP@Hf-DBA is significantly improved, and the optimal catalytic conditions are explored. The catalytic stability of HRP@Hf-DBA remained above 70% after 12 cycles of catalysis. After treatment with HRP@Hf-DBA, the apoptosis rates of A549 and Hela cells was 71.64%, and 76.86%. The results in vitro show that HRP@Hf-DBA can effectively inhibit the growth of tumor cells through enhanced CDT.


Subject(s)
Enzymes, Immobilized , Metal-Organic Frameworks , Humans , Horseradish Peroxidase/metabolism , Enzyme Stability , Metal-Organic Frameworks/pharmacology , Hydrogen Peroxide , HeLa Cells
17.
Nanoscale ; 15(48): 19486-19492, 2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38051112

ABSTRACT

Through the innovative use of surface-displayed horseradish peroxidase, this work explores the enzymatic catalysis of both bioRAFT polymerization and bioATRP to prompt polymer synthesis on the surface of Saccharomyces cerevisiae cells, with bioATRP outperforming bioRAFT polymerization. The resulting surface modification of living yeast cells with synthetic polymers allows for a significant change in yeast phenotype, including growth profile, aggregation characteristics, and conjugation of non-native enzymes to the clickable polymers on the cell surface, opening new avenues in bioorthogonal cell-surface engineering.


Subject(s)
Polymers , Saccharomyces cerevisiae , Polymerization , Saccharomyces cerevisiae/metabolism , Catalysis , Horseradish Peroxidase/metabolism
18.
Anal Chem ; 95(48): 17798-17807, 2023 12 05.
Article in English | MEDLINE | ID: mdl-37976298

ABSTRACT

The difficulty in elucidating the microenvironment of extracellular H2O2 efflux has led to the lack of a critical extracellular link in studies of the mechanisms of redox signaling pathways. Herein, we mounted horseradish peroxidase (HRP) to glycans expressed globally on the living cell surface and constructed an interception proximity labeling (IPL) platform for H2O2 efflux. The release of endogenous H2O2 is used as a "physiological switch" for HRP to enable proximity labeling. Using this platform, we visualize the oxidative stress state of tumor cells under the condition of nutrient withdrawal, as well as that of macrophages exposed to nonparticulate stimuli. Furthermore, in combination with a proteomics technique, we identify candidate proteins at the invasion interface between fungal mimics (zymosan) and macrophages by interception labeling of locally accumulated H2O2 and confirm that Toll-like receptor 2 binds zymosan in a glycan-dependent manner. The IPL platform has great potential to elucidate the mechanisms underlying biological processes involving redox pathways.


Subject(s)
Hydrogen Peroxide , Signal Transduction , Hydrogen Peroxide/metabolism , Zymosan , Horseradish Peroxidase/metabolism , Oxidation-Reduction
19.
Int J Biol Macromol ; 253(Pt 7): 127239, 2023 Dec 31.
Article in English | MEDLINE | ID: mdl-37838127

ABSTRACT

A novel immobilized enzyme driven by visible light was prepared and used for complete mineralization of antibiotics in water bodies. The immobilized enzyme was composed of carbon nitride modified by biochar (C/CN) and horseradish peroxidase (HRP), establishing the photo-enzyme coupling system with synergistic effect. Among them, the introduction of biochar not only improves the stability and loading capacity of the enzyme, but also improves the light absorption capacity and carrier separation efficiency of the photocatalyst. After the optimization of immobilization process, the solid load of HRP could reach 251.03 mg/g, and 85.03 % enzyme activity was retained after 18 days of storage at 4 °C. In the sulfadiazine (SDZ) degradation experiment, the degradation rate of HRP/C3/CN reached 71.21 % within 60 min, which was much higher than that of HRP (2.33 %), CN (49.78 %) and C3/CN (58.85 %). In addition, under the degradation of HRP/C/CN, the total organic carbon (TOC) removal rate of SDZ reached 53.14 %, which was 6.47 and 1.74 times that of CN and C3/CN, respectively. This study shows that the introduction of biochar is of great significance to the photo-enzyme cascade coupling system and provides a new strategy for the application of HRP&g-C3N4 system in wastewater treatment.


Subject(s)
Enzymes, Immobilized , Water , Enzymes, Immobilized/metabolism , Sulfadiazine , Horseradish Peroxidase/metabolism , Light
20.
Bioconjug Chem ; 34(10): 1719-1726, 2023 10 18.
Article in English | MEDLINE | ID: mdl-37767911

ABSTRACT

Lipid raft-specific glycosylation has been implicated in many biological processes, including intracellular trafficking, cell adhesion, signal transduction, and host-pathogen interactions. The major predicament in lipid raft-specific glycosylation research is the unavailability of tools for tracking and manipulating glycans on lipid rafts at the microstructural level. To overcome this challenge, we developed a multifunctional proximity labeling (MPL) platform that relies on cholera toxin B subunit to localize horseradish peroxidase on lipid rafts. In addition to the prevailing electron-rich amino acids, modified sialic acid was included in the horseradish peroxidase-mediated proximity labeling substrate via purposefully designed chemical transformation reactions. In combination with sialic acid editing, the self-renewal of lipid raft-specific sialic acid was visualized. The MPL method enabled tracking of lipid raft dynamics under methyl-ß-cyclodextrin and mevinolin treatments; in particular, the alteration of lipid rafts markedly affected cell migration. Furthermore, we embedded functional molecules into the method and implemented raft-specific sialic acid gradient engineering. Our novel strategy presents opportunities for tailoring lipid raft-specific sialic acids, thereby regulating interactions associated with lipid raft regions (such as cell-virus and cell-microenvironment interactions), and can aid in the development of lipid raft-based therapeutic regimens for tumors.


Subject(s)
N-Acetylneuraminic Acid , Sialic Acids , Cell Movement , Sialic Acids/metabolism , Membrane Microdomains/metabolism , Horseradish Peroxidase/metabolism
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