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DNA topoisomerase IIα (TOP2A) plays a vital role in replication and cell division by catalytically altering DNA topology. It is a prominent target for anticancer drugs, but clinical efficacy is often compromised due to chemoresistance. In this study, we investigate the role of TOP2A O-GlcNAcylation in breast cancer cells and patient tumor tissues. Our results demonstrate that elevated TOP2A, especially its O-GlcNAcylation, promotes breast cancer malignant progression and resistance to adriamycin (Adm). O-GlcNAcylation at Ser1469 enhances TOP2A chromatin DNA binding and catalytic activity, leading to resistance to Adm in breast cancer cells and xenograft models. Mechanistically, O-GlcNAcylation-modulated interactions between TOP2A and cell cycle regulators influence downstream gene expression and contribute to breast cancer drug resistance. These results reveal a previously unrecognized mechanistic role for TOP2A O-GlcNAcylation in breast cancer chemotherapy resistance and provide support for targeting TOP2A O-GlcNAcylation in cancer therapy.
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Antineoplásicos , Neoplasias de la Mama , Femenino , Humanos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Doxorrubicina/farmacología , Resistencia a AntineoplásicosRESUMEN
The study aims to execute machine learning (ML) method for building an intelligent prediction system for catalytic activities of a relatively big dataset of 1056 transition metal complex precatalysts in ethylene polymerization. Among 14 different algorithms, the CatBoost ensemble model provides the best prediction with the correlation coefficient (R2 ) values of 0.999 for training set and 0.834 for external test set. The interpretation of the obtained model indicates that the catalytic activity is highly correlated with number of atom, conjugated degree in the ligand framework, and charge distributions. Correspondingly, 10 novel complexes are designed and predicted with higher catalytic activities. This work shows the potential application of the ML method as a high-precision tool for designing advanced catalysts for ethylene polymerization.
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Chemodynamic therapy (CDT) is a highly targeted approach to treat cancer since it converts hydrogen peroxide into harmful hydroxyl radicals (OH·) through Fenton or Fenton-like reactions. However, the systemic toxicity of metal-based CDT agents has limited their clinical applications. Herein, a metal-free CDT agent: 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT)/ [closo-B12 H12 ]2- (TPT@ B12 H12 ) is reported. Compared to the traditional metal-based CDT agents, TPT@B12 H12 is free of metal avoiding cumulative toxicity during long-term therapy. Density functional theory (DFT) calculation revealed that TPT@B12 H12 decreased the activation barrier more than 3.5 times being a more effective catalyst than the Fe2+ ion (the Fenton reaction), which decreases the barrier about twice. Mechanismly, the theory calculation indicated that both [B12 H12 ]-· and [TPT-H]2+ have the capacity to decompose hydrogen into 1 O2 , OH·, and O2 -· . With electron paramagnetic resonance and fluorescent probes, it is confirmed that TPT@B12 H12 increases the levels of 1 O2 , OH·, and O2 -· . More importantly, TPT@B12 H12 effectively suppress the melanoma growth both in vitro and in vivo through 1 O2 , OH·, and O2 -· generation. This study specifically highlights the great clinical translational potential of TPT@B12 H12 as a CDT reagent.
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Melanoma , Neoplasias , Humanos , Melanoma/tratamiento farmacológico , Boro , Colorantes Fluorescentes , Hidrógeno , Peróxido de Hidrógeno , Metales , Línea Celular TumoralRESUMEN
MAX phase combines both ceramic and metallic properties, which exhibits widespread application prospects. 2D MAX nanosheets have more abundant surface-active sites, being anticipated to improve the performance of surface-related applications. Herein, for the first time, 2D Nb2AlC nanosheets (NSs) as novel supports anchored with Ru catalysts for overall water splitting are developed. The optimized catalyst of Ru@Nb2AlC NSs exhibit Pt-comparable kinetics and superior catalytic activity toward hydrogen evolution reaction (HER) (low overpotentials of 61 and 169 mV at 10 and 100 mA cm-2, respectively) with excellent durability (5000 cycles or 80 h) in alkaline media. In particular, Ru@Nb2AlC NSs achieve a mass activity of ≈4.8 times larger than the commercial Pt/C (20 wt.%) catalyst. The post-oxidation resultant catalyst of RuO2@Nb2AlC NSs also exhibit boosting HER and oxygen evolution reaction activities and ≈100% Faraday efficiency for overall water splitting with a cell voltage of 1.61 V to achieve 10 mA cm-2. Therefore, the novel category of 2D MAX supports anchored with Ru nanocrystals offers a novel strategy for designing a wide range of MAX-supported metal catalysts for the renewable energy field.
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Protein engineering is essential for altering the substrate scope, catalytic activity and selectivity of enzymes for applications in biocatalysis. However, traditional approaches, such as directed evolution and rational design, encounter the challenge in dealing with the experimental screening process of a large protein mutation space. Machine learning methods allow the approximation of protein fitness landscapes and the identification of catalytic patterns using limited experimental data, thus providing a new avenue to guide protein engineering campaigns. In this concept article, we review machine learning models that have been developed to assess enzyme-substrate-catalysis performance relationships aiming to improve enzymes through data-driven protein engineering. Furthermore, we prospect the future development of this field to provide additional strategies and tools for achieving desired activities and selectivities.
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Ingeniería de Proteínas , Proteínas , Biocatálisis , Catálisis , Enzimas/genética , Enzimas/metabolismo , Mutación , Ingeniería de Proteínas/métodos , Proteínas/genética , Proteínas/metabolismoRESUMEN
Platinum (Pt) nanozymes with multiple intrinsic enzyme-mimicking activities have attracted extensive attention in biomedical fields due to their high catalytic activity, ease of modification, and convenient storage. However, the Pt nanozymes synthesized by the traditional method often suffer from uncontrollable morphology and poor stability under physicochemical conditions, resulting in unsatisfactory catalytic behavior in practical applications. To optimize the catalytic ability, biological templates have been introduced recently, which can guide the deposition of platinum ions on their surface to form specific morphologies and then stabilize the resulting Pt nanozymes. Given the promising potential of biotemplated Pt nanozymes in practical applications, it is essential to conduct a systematic and comprehensive review to summarize their recent research progress. In this review, we first categorize the biological templates and discussed the mechanisms as well as characteristics of each type of biotemplate in directing the growth of Pt nanozyme. Factors that impact the growth of biotemplated Pt nanozymes are then analyzed, followed by summarizing their biomedical application. Finally, the challenges and opportunities in this field are outlined. This review article aims to provide theoretical guidance for developing Pt nanozymes with robust functionalities in biomedical applications.
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Amino acids are not only the building blocks of proteins but also lead to the development of novel nanomaterials with unique properties. Herein, we proposed a simple strategy to produce gold nanoparticles (Au NPs) with peroxidase-like (POD-like) activities by using a series of amino acids as reducing agents, named Au NPs@M (M represents different amino acids). The Au NPs@His was identified as the nanozyme with the most potent catalytic performance, which was used in combination with smartphones to achieve rapid detection of hydrogen peroxide with a detection limit of 0.966â µM. It also enables rapid detection of glucose with a detection limit of 2.904â µM, highlighting the significant contribution of Au NPs@His in expediting the detection of critical biomolecules. This work not only provides a convenient and highly efficient method to identify glucose but also shows the potential of histidine as a reducing agent in constructing Au nanomaterials exerting enzyme-like catalysis.
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MAIN CONCLUSION: Protein modeling, carbocation docking, and molecular dynamics along with structure-based mutability landscapes provided insight into taxadiene synthase catalysis (first step of the anticancer Taxol biosynthesis), protein structure-function correlations, and promiscuity. Plant terpenes belong to one of the largest and most diverse classes of natural products. This diversity is driven by the terpene synthase enzyme family which comprises numerous different synthases, several of which are promiscuous. Taxadiene synthase (TXS) is a class I diterpene synthase that catalyzes the first step in the biosynthesis pathway of the diterpene Taxol, an anticancer natural product produced by the Taxus plant. Exploring the molecular basis of TXS catalysis and its promiscuous potential garnered interest as a necessary means for understanding enzyme evolution and engineering possibilities to improve Taxol biosynthesis. A catalytically active closed conformation TXS model was designed using the artificial intelligence system, AlphaFold, accompanied by docking and molecular dynamics simulations. In addition, a mutability landscape of TXS including 14 residues was created to probe for structure-function relations. The mutability landscape revealed no mutants with improved catalytic activity compared to wild-type TXS. However, mutations of residues V584, Q609, V610, and Y688 showed high degree of promiscuity producing cembranoid-type and/or verticillene-type major products instead of taxanes. Mechanistic insights into V610F, V584M, Q609A, and Y688C mutants compared to the wild type revealed the trigger(s) for product profile change. Several mutants spanning residues V584, Q609, Y688, Y762, Q770, and F834 increased production of taxa-4(20),11(12)-diene which is a more favorable substrate for Taxol production compared to taxa-4(5),11(12)-diene. Finally, molecular dynamics simulations of the TXS reaction cascade revealed residues involved in ionization, carbocation stabilization, and cyclization ushering deeper understanding of the enzyme catalysis mechanism.
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Diterpenos , Isomerasas , Simulación de Dinámica Molecular , Inteligencia Artificial , Paclitaxel , Diterpenos/metabolismo , CatálisisRESUMEN
Aminoacyl-tRNA synthetases (AaRSs) are valuable "housekeeping" enzymes that ensure the accurate transmission of genetic information in living cells, where they aminoacylated tRNA molecules with their cognate amino acid and provide substrates for protein biosynthesis. In addition to their translational or canonical function, they contribute to nontranslational/moonlighting functions, which are mediated by the presence of other domains on the proteins. This was supported by several reports which claim that AaRS has a significant role in gene transcription, apoptosis, translation, and RNA splicing regulation. Noncanonical/ nontranslational functions of AaRSs also include their roles in regulating angiogenesis, inflammation, cancer, and other major physio-pathological processes. Multiple AaRSs are also associated with a broad range of physiological and pathological processes; a few even serve as cytokines. Therefore, the multifunctional nature of AaRSs suggests their potential as viable therapeutic targets as well. Here, our discussion will encompass a range of noncanonical functions attributed to Aminoacyl-tRNA Synthetases (AaRSs), highlighting their links with a diverse array of human diseases.
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Aminoacil-ARNt Sintetasas , Humanos , Aminoacil-ARNt Sintetasas/genética , Aminoacil-ARNt Sintetasas/metabolismo , ARN de Transferencia/metabolismo , Empalme del ARNRESUMEN
Pq3-O-UGT2, derived from Panax quinquefolius, functions as a ginsenoside glucosyltransferase, utilizing UDP-glucose (UDPG) as the sugar donor to catalyze the glycosylation of Rh2 and F2. An essential step in comprehending its catalytic mechanism involves structural analysis. In preparation for structural analysis, we expressed Pq3-O-UGT2 in the Escherichia coli (E. coli) strain Rosetta (DE3). The recombinant Pq3-O-UGT2 was purified through Ni-NTA affinity purification, a two-step ion exchange chromatography, and subsequently size-exclusion chromatography (SEC). Notably, the purified Pq3-O-UGT2 showed substantial activity toward Rh2 and F2, catalyzing the formation of Rg3 and Rd, respectively. This activity was discernible within a pH range of 4.0-9.0 and temperature range of 30-55 °C, with optimal conditions observed at pH 7.0-8.0 and 37 °C. The catalytic efficiency of Pq3-O-UGT2 toward Rh2 and F2 was 31.43 s-1 mΜ-1 and 169.31 s-1 mΜ-1, respectively. We further crystalized Pq3-O-UGT2 in both its apo form and co-crystalized forms with UDPG, Rh2 and F2, respectively. High-quality crystals were obtained and X-ray diffraction data was collected for all co-crystalized samples. Analysis of the diffraction data revealed that the crystal of Pq3-O-UGT2 co-crystalized with UDP-Glc belonged to space group P1, while the other two crystals belonged to space group P212121. Together, this study has laid a robust foundation for subsequent structural analysis of Pq3-O-UGT2.
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Ginsenósidos , Panax , Ginsenósidos/metabolismo , Glicosiltransferasas , Uridina Difosfato Glucosa , Panax/genética , Panax/química , Panax/metabolismo , Cristalización , Escherichia coli/genética , Escherichia coli/metabolismoRESUMEN
Recently, gold nanomaterials have been rapidly developed owing to their high stability, good biocompatibility, and multifunctionality. The unique catalytic activity of gold nanomaterials has driven the emergence of the concept for a "gold nanozyme." Understanding the characteristics of gold nanozymes is crucial for improving their catalytic performance as well as expanding their applications. In this review, we provide an overview of the intrinsic enzyme-like activities of gold nanozymes, including peroxidase-, catalase-, superoxide dismutase-, and glucose oxidase-like activities, and the catalytic mechanisms involved. In addition, strategies for modulating the catalytic activity of gold nanozymes and their applications in biosensing were discussed in detail. Moreover, we highlight the current challenges of gold nanozymes and look forward to attracting more attention for propelling the developments in this field.
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Hydration, a secondary activity mediated by nitrilase, is a promising new pathway for amide production. However, low hydration activity of nitrilase or trade-off between hydration and catalytic activity hinders its application in the production of amides. Here, natural C-terminal-truncated wild-type nitrilase, mined from a public database, obtained a high-hydration activity nitrilase as a novel evolutionary starting point for further protein engineering. The nitrilase Nit-74 from Spirosoma linguale DSM 74 was successfully obtained and exhibited the highest hydration activity level, performing 50.7 % nicotinamide formation and 87.6 % conversion to 2 mM substrate 3-cyanopyridine. Steric hindrance of the catalytic activity center and the N-terminus of the catalytic cysteine residue helped us identify three key residues: I166, W168, and T191. Saturation mutations resulted in three single mutants that further improved the hydration activity of N-heterocyclic nitriles. Among them, the mutant T191S performed 72.7 % nicotinamide formation, which was much higher than the previously reported highest level of 18.7 %. Additionally, mutants I166N and W168Y exhibited a 97.5 % 2-picolinamide ratio and 97.7 % isonicotinamide ratio without any loss of catalytic activity, which did not indicate a trade-off effect. Our results expand the screening and evolution library of promiscuous nitrilases with high hydration activity for amide formation.
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Aminohidrolasas , Cytophagaceae , Nitrilos , Pirimidinas , Triazoles , Nitrilos/química , Aminohidrolasas/genética , Aminohidrolasas/química , Aminohidrolasas/metabolismo , Amidas , Niacinamida , Especificidad por SustratoRESUMEN
Traditional microbial electrochemical sensors encounter challenges due to their inherent complexity. In response to these challenges, the microbial potentiometric sensor (MPS) technology was introduced, featuring a straightforward high-impedance measurement circuit tailored for environmental monitoring. Nonetheless, the practical implementation of conventional MPS is constrained by issues such as the exposure of the reference electrode to the monitored water and the absence of methodologies to stimulate microbial metabolism. In this study, our objective was to enhance MPS performance by imbuing it with unique cathodic catalytic properties, specifically tailored for distinct application scenarios. Notably, the anodic region served as the sensing element, with both the cathodic region and reference electrode physically isolated from the analyzed water sample. In the realm of organic monitoring, the sensor without Pt/C coated in the cathodic region exhibited a faster response time (1 h) and lower detection limits (1 mg L-1 BOD, 1 mM acetic acid). Conversely, when monitoring toxic substances, the sensor with Pt/C showcased a lower detection limit (0.004% formaldehyde), while the Pt/C-free sensor demonstrated superior reusability. The sensor with Pt/C displayed a heightened anode biofilm thickness and coverage, predominantly composed of Rhodococcus. In conclusion, this study introduces simple, cost-effective, and tailorable biosensors holding substantial promise for water quality monitoring.
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Técnicas Biosensibles , Monitoreo del Ambiente , Electrodos , Monitoreo del Ambiente/métodos , Técnicas Biosensibles/métodos , Calidad del AguaRESUMEN
Geranylgeranyl diphosphate synthase (GGPPS) as the short-chain prenyltransferases for catalyzing the formation of the acyclic precursor (E)-GGPP has been extensively investigated in mammals, plants, and microbes, but its functional plasticity is poorly understood in insect species. Here, a single GGPPS in leaf beetle Monolepta hieroglyphica, MhieGGPPS, was functionally investigated. Phylogenetic analysis showed that MhieGGPPS was clustered in one clade with homologs and had six conserved motifs. Molecular docking results indicated that binding sites of dimethylallyl diphosphate (DMAPP), (E)-geranyl pyrophosphate (GPP), and (E)-farnesyl pyrophosphate (FPP) were in the chain-length determination region of MhieGGPPS, respectively. In vitro, recombiant MhieGGPPS could catalyze the formation of (E)-geranylgeraniol against different combinations of substrates including isopentenyl pyrophosphate (IPP)/DMAPP, IPP/(E)-GPP, and IPP/(E)-FPP, suggesting that MhieGGPPS could not only use (E)-FPP but also (E)-GPP and DMAPP as the allylic cosubstrates. In kinetic analysis, the (E)-FPP was most tightly bound to MhieGGPPS than that of others. It was proposed that MhieGGPPS as a multifunctional enzyme is differentiated from the other GGPPSs in the animals and plants, which only accepted (E)-FPP as the allylic cosubstrate. These findings provide valuable insights into understanding the functional plasticity of GGPPS in M. hieroglyphica and the novel biosynthesis mechanism in the isoprenoid pathway.
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Escarabajos , Hemiterpenos , Compuestos Organofosforados , Fosfatos de Poliisoprenilo , Sesquiterpenos , Animales , Farnesiltransferasa , Cinética , Simulación del Acoplamiento Molecular , Filogenia , MamíferosRESUMEN
Pentacyclic triterpenoids exhibit a wide range of biological activities which have wide applications in the food, cosmetics, and pharmaceutical industries. High-performance chassis strains have been developed for the production of various pentacyclic triterpenoids, e.g., lupane-type and oleanane-type triterpenoids. The production of common pentacyclic triterpenes and their derivatives is limited by the poor activity of typical pentacyclic triterpene synthases (PTSs). However, a general strategy applicable to typical PTSs is still lacking. As typical pentacyclic triterpenes are derived from the baccharenyl cation, engineering the non-active-site residues in the MXXXXR motif might be beneficial for the catalytic efficiencies of typical PTSs by the stabilization of the baccharenyl cation. Here, we develop a general strategy for improving the activity of typical PTSs. As a proof of concept, the activity of three PTSs such as lupeol synthase, ß-amyrin synthase, and α-amyrin synthases was significantly increased up to 7.3-fold by site-directed saturation mutagenesis. This strategy could be applied to improve the activity of various typical PTSs. KEY POINTS: ⢠The strategy could be applied to typical PTSs for improving the activity. ⢠The catalytic activity of typical PTSs was significantly increased.
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Triterpenos , Aminoácidos , Triterpenos Pentacíclicos , Catálisis , CationesRESUMEN
Cerium oxide (CeO2) nanospheres have limited enzymatic activity that hinders further application in catalytic therapy, but they have an "oxidation switch" to enhance their catalytic activity by increasing oxygen vacancies. In this study, according to the defect-engineering strategy, we developed PtCuOX/CeO2-X nanozymes as highly efficient SOD/CAT mimics by introducing bimetallic copper (Cu) and platinum (Pt) into CeO2 nanospheres to enhance the oxygen vacancies, in an attempt to combine near-infrared (NIR) irradiation to regulate microenvironment for osteoarthritis (OA) therapy. As expected, the Cu and Pt increased the Ce3+/Ce4+ ratio of CeO2 to significantly enhance the oxygen vacancies, and simultaneously CeO2 (111) facilitated the uniform dispersion of Cu and Pt. The strong metal-carrier interaction synergy endowed the PtCuOX/CeO2-X nanozymes with highly efficient SOD/CAT-like activity by the decreased formation energy of oxygen vacancy, promoted electron transfer, the increased adsorption energy of intermediates, and the decreased reaction activation energy. Besides, the nanozymes have excellent photothermal conversion efficiency (55.41%). Further, the PtCuOX/CeO2-X antioxidant system effectively scavenged intracellular ROS and RNS, protected mitochondrial function, and inhibited the inflammatory factors, thus reducing chondrocyte apoptosis. In vivo, experiments demonstrated the biosafety of PtCuOX/CeO2-X and its potent effect on OA suppression. In particular, NIR radiation further enhanced the effects. Mechanistically, PtCuOX/CeO2-X nanozymes reduced ras-related C3 botulinum toxin substrate 1 (Rac-1) and p-p65 protein expression, as well as ROS levels to remodel the inflammatory microenvironment by inhibiting the ROS/Rac-1/nuclear factor kappa-B (NF-κB) signaling pathway. This study introduces new clinical concepts and perspectives that can be applied to inflammatory diseases.
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Cerio , Cobre , Osteoartritis , Platino (Metal) , Superóxido Dismutasa , Cerio/química , Cerio/farmacología , Cobre/química , Cobre/farmacología , Animales , Superóxido Dismutasa/metabolismo , Osteoartritis/tratamiento farmacológico , Osteoartritis/metabolismo , Platino (Metal)/química , Platino (Metal)/farmacología , Ratones , Oxígeno/metabolismo , Oxígeno/química , Especies Reactivas de Oxígeno/metabolismo , Catalasa/metabolismo , Catalasa/química , Humanos , Condrocitos/metabolismo , Condrocitos/efectos de los fármacos , Antioxidantes/farmacología , Antioxidantes/química , Microambiente Celular/efectos de los fármacos , MasculinoRESUMEN
Colorimetric qualitative and sensitive quantitative detection of Salmonella Typhimurium (S. Typhimurium) holds significant importance for ensuring food safety and preventing foodborne illnesses. In the study, an ultra-high catalytic activity and biocompatible nickel-platinum nanoparticle (NiPt NP) nanozyme is successful synthesized to prepare a NLISA strategy for the detection of S. Typhimurium. The synthesized NiPt NPs exhibit high oxidase-like catalytic efficiency, with a Michaelis constant (Km) of 0.493 mM, similar to that of natural horseradish peroxidase (HRP). The maximal reaction velocity (Vmax) was determined to be 1.97 × 10-7 M·s-1 exhibiting a 1.97-fold higher than that of the HRP (1.0 × 10-7 M·s-1). Meanwhile, the antibody employed in this NiPt NPs-based NLISA exhibits exceptional capture efficacy, generating a stable immune complex with S. Typhimurium. The NiPt NPs-based NLISA demonstrates sensitivity, specificity, convenience, and cost-efficiency for the detection of S. Typhimurium. Under optimal conditions, this NiPt NPs-based NLISA demonstrates a quantitative range of 103â¼106 cfu/mL with a detection limit as low as 103 cfu/mL. A single-blind experimental testing detects different concentrations of S. Typhimurium spiked skim milk, indicating the application potential of the proposed NLISA in real samples. In all, this research provides novel insights into the synthesis of nanozymes with excellent catalytic activity and their applications in S. Typhimurium biosensing.
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ASH1L potentially contributes to Tourette syndrome (TS) and other neuropsychiatric disorders, as our previous studies have shown. It regulates essential developmental genes by counteracting polycomb-mediated transcriptional repression, which restricts chromatin accessibility at target genes. ASH1L is highly expressed in the adult brain, playing a crucial role in the early stage. However, it remains unclear how ASH1L mutations carried by patients with TS participate in regulating neuronal growth processes leading to TS traits. Five TS families recruited in our study underwent comprehensive physical examinations and questionnaires to record clinical phenotypes and environmental impact factors. We validated the variants via Sanger sequencing and constructed two mutants near the catalytic domain of ASH1L. We conducted molecular modeling, in vitro assays, and primary neuron cultures to find the role of ASH1L in neuronal development and its correlation with TS. In this study, we validated five pathogenic ASH1L rare variants and observed symptoms in patients with simple tics and behavioral comorbidities. Mutations near the catalytic domain of TS patients cause mental state abnormalities and disrupt ASH1L function by destabilizing its spatial conformation, leading to decreased activity of catalytic H3K4, thereby affecting the neurite growth. We need to conduct larger-scale studies on TS patients and perform additional neurological evaluations on mature neurons. We first reported the effects of ASH1L mutations in TS patients, including phenotypic heterogeneity, protein function, and neurological growth. This information contributes to understanding the neurodevelopmental pathogenesis of TS in patients with ASH1L mutations.
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An ultrasensitive sandwich-type electrochemical immunosensor for pro-gastrin-releasing peptide (ProGRP) detection was constructed based on PtCu nanodendrites functionalized Au/polyaniline nanospheres (Au/PANI@PtCu). The prepared Au/PANI@PtCu nanocomposites not only possessed excellent electro-catalytic activity of H2O2 reduction due to the synergistic effect between the Au/PANI and PtCu NDs but also provided large specific surface area for detection of antibodies (Ab2) immobilization. In addition, Au nanoparticles encapsulated multi-wall carbon nanotubes (AuNPs@MWCNTs) were also applied to modify the glassy carbon electrode interface for loading numerous capture antibodies (Ab1). In the presence of target ProGRP, a sandwich-type electrochemical immunosensor showed a strong current response from the electro-catalysis of Au/PANI@PtCu toward H2O2 reduction. Benefiting from the exceptional electro-catalytic performance of Au/PANI@PtCu and the high conductivity of AuNPs@MWCNTs, the sandwich-type immunoassay exhibited remarkable sensitivity in detection. The linear range extended from 100 fg/mL to 10 ng/mL, while achieving an impressively low limit of detection of 77.62 fg/mL.
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Técnicas Biosensibles , Nanopartículas del Metal , Nanotubos de Carbono , Péptido Liberador de Gastrina , Oro , Peróxido de Hidrógeno , Anticuerpos Inmovilizados , Inmunoensayo , AnticuerposRESUMEN
The ethylenediaminetetradiacetic acid (EDTA) is one of the most commonly used irrigation solutions. Although EDTA has a very low antimicrobial property, it is used to remove inorganic part of smear layer in areas of root canal system. Herein, we developed EDTA-incorporated nanoflowers (EDTA NFs), for the first time, as novel and effective irrigation solution with quite high antimicrobial property to provide complete disinfection in root canal system. We both systematically elucidated the formation of the EDTA NFs with various techniques, and their catalytic and antimicrobial activities in the presence of hydrogen peroxide (H2O2) were documented through intrinsic EDTA property and peroxidase-like activities.