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1.
Nanomaterials (Basel) ; 14(11)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38869561

RESUMO

With a rising interest in smart windows and optical displays, the utilization of metal oxides (MOs) has garnered significant attention owing to their high active sites, flexibility, and tunable electronic and optical properties. Despite these advantages, achieving precise tuning of optical properties in MOs-based quantum dots and their mass production remains a challenge. In this study, we present an easily scalable approach to generate WO3 quantum dots with diverse sizes through sequential insertion/exfoliation processes in solvents with suitable surface tension. Additionally, we utilized the prepared WO3 quantum dots in the fabrication of luminescent transparent wood via an impregnation process. These quantum dots manifested three distinct emitting colors: red, green, and blue. Through characterizations of the structural and optical properties of the WO3 quantum dots, we verified that quantum dots with sizes around 30 nm, 50 nm, and 70 nm showcase a monoclinic crystal structure with oxygen-related defect sites. Notably, as the size of the WO3 quantum dots decreased, the maximum emitting peak underwent a blue shift, with peaks observed at 407 nm (blue), 493 nm (green), and 676 nm (red) under excitation by a He-Cd laser (310 nm), respectively. Transparent woods infused with various WO3 quantum dots exhibited luminescence in blue/white emitting colors. These results suggest substantial potential in diverse applications, such as building materials and optoelectronics.

2.
Int J Mol Sci ; 25(11)2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38892385

RESUMO

Aging leads to tissue and cellular changes, often driven by oxidative stress and inflammation, which contribute to age-related diseases. Our research focuses on harnessing the potent anti-inflammatory and antioxidant properties of Korean Ulmus macrocarpa Hance, a traditional herbal remedy, to address muscle loss and atrophy. We evaluated the effects of Ulmus extract on various parameters in a muscle atrophy model, including weight, exercise performance, grip strength, body composition, muscle mass, and fiber characteristics. Additionally, we conducted Western blot and RT-PCR analyses to examine muscle protein regulation, apoptosis factors, inflammation, and antioxidants. In a dexamethasone-induced muscle atrophy model, Ulmus extract administration promoted genes related to muscle formation while reducing those associated with muscle atrophy. It also mitigated inflammation and boosted muscle antioxidants, indicating a potential improvement in muscle atrophy. These findings highlight the promise of Ulmus extract for developing pharmaceuticals and supplements to combat muscle loss and atrophy, paving the way for clinical applications.


Assuntos
Extratos Vegetais , Sarcopenia , Ulmus , Ulmus/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Camundongos Endogâmicos C57BL , Masculino , Animais , Camundongos , Sarcopenia/tratamento farmacológico , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos
3.
Gene Ther ; 31(7-8): 358-365, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38918512

RESUMO

The recently developed CRISPR activator (CRISPRa) system uses a CRISPR-Cas effector-based transcriptional activator to effectively control the expression of target genes without causing DNA damage. However, existing CRISPRa systems based on Cas9/Cas12a necessitate improvement in terms of efficacy and accuracy due to limitations associated with the CRISPR-Cas module itself. To overcome these limitations and effectively and accurately regulate gene expression, we developed an efficient CRISPRa system based on the small CRISPR-Cas effector Candidatus Woesearchaeota Cas12f (CWCas12f). By engineering the CRISPR-Cas module, linking activation domains, and using various combinations of linkers and nuclear localization signal sequences, the optimized eCWCas12f-VPR system enabled effective and target-specific regulation of gene expression compared with that using the existing CRISPRa system. The eCWCas12f-VPR system developed in this study has substantial potential for controlling the transcription of endogenous genes in living organisms and serves as a foundation for future gene therapy and biological research.


Assuntos
Sistemas CRISPR-Cas , Humanos , Regulação da Expressão Gênica , Edição de Genes/métodos , Células HEK293 , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
4.
Biochem Biophys Res Commun ; 727: 150310, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38941793

RESUMO

Targeting the hydrophobic Phe43 pocket of HIV's envelope glycoprotein gp120 is a critical strategy for antiviral interventions due to its role in interacting with the host cell's CD4. Previous inhibitors, including small molecules and CD4 mimetic peptides based on scyllatoxin, have demonstrated significant binding and neutralization capabilities but were often chemically synthesized or contained non-canonical amino acids. Microbial expression using natural amino acids offers advantages such as cost-effectiveness, scalability, and efficient production of fusion proteins. In this study, we enhanced the previous scyllatoxin-based synthetic peptide by substituting natural amino acids and successfully expressed it in E. coli. The peptide was optimized by mutating the C-terminal amidated valine to valine and glutamine, and by reducing the disulfide bonds from three to two. Circular dichroism confirmed proper secondary structure formation, and fluorescence polarization analysis revealed specific, concentration-dependent binding to HIV gp120, supported by molecular dynamics simulations. These findings indicate the potential for scalable microbial production of effective antiviral peptides, with significant applications in pharmaceutical development for HIV treatment.


Assuntos
Escherichia coli , Proteína gp120 do Envelope de HIV , Peptídeos , Ligação Proteica , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Escherichia coli/metabolismo , Escherichia coli/genética , Peptídeos/química , Peptídeos/metabolismo , Peptídeos/farmacologia , Simulação de Dinâmica Molecular , Humanos , Sequência de Aminoácidos , Desenho de Fármacos
5.
ACS Appl Mater Interfaces ; 16(23): 30137-30146, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38814156

RESUMO

The use of powered activated carbon is often limited by inconsistent particle sizes and porosities, leading to reduced adsorption efficiencies. In this study, we demonstrated a practical and environmentally friendly method for creating a 3D graphene nanostructure with highly uniform ultramicropores from wood-based biomass through a series of delignification, carbonization, and activation processes. In addition, we evaluated the capture characteristics of this structure for CO2, CH4, and N2 gases as well as its selectivity for binary-mixture gases. Based on textural and chemical analyses, the delignified monolith had a lamellar structure interconnected by cellulose-based fibers. Interestingly, applying the KOH vapor activation technique solely to the delignified samples led to the formation of a monolithic 3D network composed of interconnected graphene sheets with a high degree of crystallinity. Especially, the Act. 1000 sample exhibited a specific surface area of 1480 m2/g and a considerable pore volume of 0.581 cm3/g, featuring consistently uniform ultramicropores over 90% in the range of 3.5-11 Å. The monolithic graphene-based samples, predominantly composed of ultramicropores, demonstrated a notably heightened capture capacity of 6.934 mol/kg at 110 kPa for CO2, along with favorable selectivity within binary gas mixtures (CO2/N2, CO2/CH4, and CO2/CH4). Our findings suggest that this biomass-derived 3D structure has the potential to serve as a monolithic adsorbent in gas separation applications.

6.
Plast Reconstr Surg ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38652871

RESUMO

BACKGROUND: Traditional skin grafts for syndactyly often cause color mismatches and unsightly donor sites, whereas no-skin-graft methods leave noticeable dorsal hand scars. This study presents plantar full-thickness skin graft (FTSG) from the weight-bearing midline area for syndactyly repair, a novel approach not previously reported in the literature. METHODS: The study included three groups of patients with congenital syndactyly of the hand who underwent primary operations with plantar FTSG (n=70), groin FTSG (n=20), and no-skin-graft techniques (n=22). Postoperative outcomes were evaluated by an assessment panel, and guardians' satisfaction scores were measured. Color similarity between the graft and surrounding skin was assessed using a three-dimensional color space. RESULTS: The plantar FTSG group demonstrated a significantly higher likelihood of receiving an 'excellent' rating compared to the groin FTSG group, with an odds ratio of 6.30 (p<0.001). Color difference analysis showed that plantar FTSG more closely matched surrounding skin color than groin FTSG (6.33 vs. 22.57, p<0.001). Guardians reported greater satisfaction with outcomes on the hand in the plantar FTSG group compared to the groin FTSG and no-skin-graft groups (7.16 vs. 5.05 and 4.36, p<0.001). Satisfaction with donor sites was also significantly higher in the plantar FTSG group than in the groin FTSG group (8.23 vs. 6.30, p<0.001). CONCLUSION: Correction of congenital hand syndactyly using midline plantar FTSG from the weight-bearing area can reduce scarring on the hand dorsum, ensure superior color similarity with surrounding skin, and offer inconspicuous donor sites compared to no-skin-graft or groin FTSG techniques.

7.
Int J Biol Macromol ; 268(Pt 2): 131908, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38679269

RESUMO

Curcuma longa and Sargassum coreanum are commonly used in traditional pharmaceutical medicine to improve immune function in chronic diseases. The present study was designed to systematically elucidate the in vitro and in vivo immuno-enhancing effects of a combination of C. longa and S. coreanum extracts (CS) that contain polyphenols and saccharides as functional molecules in a cyclophosphamide (Cy)-induced model of immunosuppression. In primary splenocytes, we observed the ameliorative effects of CS on a Cy-induced immunosuppression model with low cytotoxicity and an optimal mixture procedure. CS treatment enhanced T- and B-cell proliferation, increased splenic natural killer-cell activity, and restored cytokine release. Wistar rats were orally administered low (30 mg/kg), intermediate (100 mg/kg), or high (300 mg/kg) doses of CS for four weeks, followed by oral administration of Cy (5 mg/kg) for four weeks. Compared with the vehicle group, low-, intermediate-, and high-dose CS treatment accelerated dose-dependent recovery of the serum level of tumor necrosis factor-α, interferon-γ, interleukin-2, and interleukin-12. These results suggest that CS treatment accelerates the amelioration of immune deficiency in Cy-treated primary splenocytes and rats, which supports considering it for immunity maintenance. Our findings provide experimental evidence for further research and clinical application in immunosuppressed patients.


Assuntos
Células Matadoras Naturais , Polifenóis , Ratos Wistar , Baço , Animais , Polifenóis/farmacologia , Polifenóis/química , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Ratos , Baço/efeitos dos fármacos , Baço/imunologia , Baço/citologia , Citocinas/metabolismo , Masculino , Ciclofosfamida/farmacologia , Proliferação de Células/efeitos dos fármacos , Extratos Vegetais/farmacologia , Extratos Vegetais/química
8.
Hand Clin ; 40(2): 301-313, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38553101

RESUMO

In hand and upper extremity replantation surgery, simultaneous free flap reconstruction restores the physiologic circulation to the amputated part, ensuring its survival, and promotes wound healing through anatomic restoration. Especially in digit replantation, an arterialized venous flap serves to reconstruct both vessel and soft tissue defects simultaneously. Delayed free flap reconstruction aims to enhance both functional improvement and cosmetic acceptance in a successfully replanted part using flaps that include functioning muscle, bone, joint, nerve, and soft tissue.


Assuntos
Procedimentos de Cirurgia Plástica , Reimplante , Humanos , Retalhos Cirúrgicos , Cicatrização , Extremidade Superior
9.
Plast Reconstr Surg Glob Open ; 12(1): e5551, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38268717

RESUMO

Reconstruction of traumatic nail bed defects in the digits is a frequently encountered procedure, yet often presents many challenges. In such scenarios, staged procedures may be required with significant limitations in shape and increased donor site morbidity, particularly when multiple defects are present. In this study, we introduce a simple method for the reconstruction of nail bed defects using an acellular dermal matrix (ADM). The study involved 19 digits with nail defects, which underwent reconstruction using an ADM graft. The surgical procedure was performed on all patients on the day of injury, after which they were promptly discharged. The dimensions of the defect ranged from 0.5 × 0.5 cm to a maximum of 2 × 3 cm (average, 0.9 × 1.4 cm). Final examinations were performed at postoperative 5-11 months (average, 6.6 months). All ADM grafts were successfully taken. Nail growth was observed at an average of 4 months after surgery in the treated finger. The surgical results were retrospectively evaluated using the Zook criteria. Outcomes were "excellent" in 11 patients (57.9%), "very good" in five patients (26.3%), "good" in two patients (10.5%), and "fair" in one patient (5.2%). The expanded application of ADM explored in this study illustrates a straightforward method for the reconstruction of traumatic nail bed defects, providing effective results in a single stage without incurring donor site morbidity.

10.
Nat Commun ; 14(1): 8033, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38052830

RESUMO

Endonucleases have recently widely used in molecular diagnostics. Here, we report a strategy to exploit the properties of Argonaute (Ago) proteins for molecular diagnostics by introducing an artificial nucleic acid circuit with Ago protein (ANCA) method. The ANCA is designed to perform a continuous autocatalytic reaction through cross-catalytic cleavage of the Ago protein, enabling one-step, amplification-free, and isothermal DNA detection. Using the ANCA method, carbapenemase-producing Klebsiella pneumoniae (CPKP) are successfully detected without DNA extraction and amplification steps. In addition, we demonstrate the detection of carbapenem-resistant bacteria in human urine and blood samples using the method. We also demonstrate the direct identification of CPKP swabbed from surfaces using the ANCA method in conjunction with a three-dimensional nanopillar structure. Finally, the ANCA method is applied to detect CPKP in rectal swab specimens from infected patients, achieving sensitivity and specificity of 100% and 100%, respectively. The developed method can contribute to simple, rapid and accurate diagnosis of CPKP, which can help prevent nosocomial infections.


Assuntos
Antibacterianos , Ácidos Nucleicos , Humanos , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , beta-Lactamases/genética , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Anticorpos Anticitoplasma de Neutrófilos/metabolismo , Ácidos Nucleicos/metabolismo , Bactérias/genética , DNA/metabolismo , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/metabolismo , Testes de Sensibilidade Microbiana
11.
Commun Chem ; 6(1): 265, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38057441

RESUMO

The diterpene glycosyltransferase UGT76G1, derived from Stevia rebaudiana, plays a pivotal role in the biosynthesis of rebaudioside A, a natural sugar substitute. Nevertheless, its potential for industrial application is limited by certain enzymatic characteristics, notably thermostability. To enhance the thermostability and enzymatic activity, we employed a computational design strategy, merging stabilizing mutation scanning with a Rosetta-based protein design protocol. Compared to UGT76G1, the designed variant 76_4 exhibited a 9 °C increase in apparent Tm, a 2.55-fold increase rebaudioside A production capacity, and a substantial 11% reduction in the undesirable byproduct rebaudioside I. Variant 76_7 also showed a 1.91-fold enhancement rebaudioside A production capacity, which was maintained up to 55 °C, while the wild-type lost most of its activity. These results underscore the efficacy of structure-based design in introducing multiple mutations simultaneously, which significantly improves the enzymatic properties of UGT76G1. This strategy provides a method for the development of efficient, thermostable enzymes for industrial applications.

12.
Int J Mol Sci ; 24(24)2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38139186

RESUMO

Fisetin is a flavonoid found in plants and has been reported to be effective in various human diseases. However, the effective mechanisms of ultraviolet-A (UVA)-mediated skin damage are not yet clear. In this study, we investigated the protective mechanisms of fisetin regarding UVA-induced human dermal fibroblasts (HDFs) and human epidermal keratinocytes (HEKs) damages. Fisetin showed a cytoprotective effect against UVA irradiation and suppressed matrix metalloproteinases (MMPs), MMP-1, and MMP-3 expression. In addition, fisetin was rescued, which decreased mRNA levels of pro-inflammatory cytokines, reactive oxygen species production, and the downregulation of MAPK/AP-1 related protein and NADPH oxidase (NOX) mRNA levels. Furthermore, UVA-induced MMP-1 and MMP-3 were effectively inhibited by siRNAs to NOX 1 to 5 in HDFs and HEKs. These results indicate that fisetin suppresses UVA-induced damage through the NOX/ROS/MAPK pathway in HDFs and HEKs.


Assuntos
Metaloproteinase 1 da Matriz , Metaloproteinase 3 da Matriz , Humanos , Espécies Reativas de Oxigênio/metabolismo , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/genética , Metaloproteinase 3 da Matriz/metabolismo , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Células Cultivadas , Pele/metabolismo , Queratinócitos/metabolismo , Fibroblastos/metabolismo , RNA Mensageiro/metabolismo , Raios Ultravioleta/efeitos adversos
13.
ACS Macro Lett ; 12(11): 1569-1575, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37931088

RESUMO

A clear understanding of the structure-property relationship of intrinsically stretchable polymer semiconductors (ISPSs) is essential for developing high-performance polymer-based electronics. Herein, we investigate the effect of the fluorination position on the crystalline structure, charge-carrier mobility, and stretchability of polymer semiconductors based on a benzodithiophene-co-benzotriazole configuration. Although four different polymer semiconductors showed similar field-effect mobilities for holes (µ ≈ 0.1 cm2 V-1 s-1), polymer semiconductors with nonfluorinated backbones exhibited improved thin-film stretchability confirmed with crack onset strain (εc ≈ 20%-50%) over those of fluorinated counterparts (εc ≤ 10%). The enhanced stretchability of polymer semiconductors with a nonfluorinated backbone is presumably due to the higher face-on crystallite ratio and π-π stacking distance in the out-of-plane direction than those of the other polymer semiconductors. These results provide new insights into how the thin-film stretchability of polymer semiconductors can be improved by using precise molecular tailoring without deteriorating electrical properties.

14.
Nanomaterials (Basel) ; 13(22)2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37999315

RESUMO

Activated carbon (AC) compounds derived from biomass precursors have garnered significant attention as electrode materials in electric double-layer capacitors (EDLCs) due to their ready availability, cost-effectiveness, and potential for mass production. However, the accessibility of their active sites in electrochemistry has not been investigated in detail. In this study, we synthesized two novel macro/micro-porous carbon structures prepared from a chitosan precursor using an acid/potassium hydroxide activation process and then examined the relationship between their textural characteristics and capacitance as EDLCs. The material characterizations showed that the ACs, prepared through different activation processes, differed in porosity, with distinctive variations in particle shape. The sample activated at 800 °C (Act-chitosan) was characterized by plate-shaped particles, a specific surface area of 4128 m2/g, and a pore volume of 1.87 cm3/g. Assessment of the electrochemical characteristics of Act-chitosan showed its remarkable capacitance of 183.5 F/g at a scan rate of 5 mV/s, and it maintained exceptional cyclic stability even after 10,000 cycles. The improved electrochemical performance of both chitosan-derived carbon structures could thus be attributed to their large, well-developed active sites within pores < 2 nm, despite the fact that interconnected macro-porous particles can enhance ion accessibility on electrodes. Our findings provide a basis for the fabrication of biomass-based materials with promising applications in electrochemical energy storage systems.

15.
Sci Rep ; 13(1): 16763, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798384

RESUMO

The CRISPR-Cas9 system is a widely used gene-editing tool, offering unprecedented opportunities for treating various diseases. Controlling Cas9/dCas9 activity at specific location and time to avoid undesirable effects is very important. Here, we report a conditionally active CRISPR-Cas9 system that regulates target gene expression upon sensing cellular environmental change. We conjugated the oxygen-sensing transcription activation domain (TAD) of hypoxia-inducing factor (HIF-1α) with the Cas9/dCas9 protein. The Cas9-TAD conjugate significantly increased endogenous target gene cleavage under hypoxic conditions compared with that under normoxic conditions, whereas the dCas9-TAD conjugate upregulated endogenous gene transcription. Furthermore, the conjugate system effectively downregulated the expression of SNAIL, an essential gene in cancer metastasis, and upregulated the expression of the tumour-related genes HNF4 and NEUROD1 under hypoxic conditions. Since hypoxia is closely associated with cancer, the hypoxia-dependent Cas9/dCas9 system is a novel addition to the molecular tool kit that functions in response to cellular signals and has potential application for gene therapeutics.


Assuntos
Sistemas CRISPR-Cas , Neoplasias , Humanos , Sistemas CRISPR-Cas/genética , Regulação da Expressão Gênica , Proteína 9 Associada à CRISPR/genética , Edição de Genes , Hipóxia/genética , Neoplasias/genética
16.
Nanomaterials (Basel) ; 13(14)2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37513086

RESUMO

Metallic-phase transition metal dichalcogenide quantum dots (TMDs-mQDs) have been reported in recent years. However, a dominant mechanism for modulating their intrinsic exciton behaviors has not been determined yet as their size is close to the Bohr radius. Herein, we demonstrate that the oxidation effect prevails over quantum confinement on metallic-phase tungsten dichalcogenide QDs (WX2-mQDs; X = S, Se) when the QD size becomes larger than the exciton Bohr radius. WX2-mQDs with a diameter of ~12 nm show an obvious change in their photophysical properties when the pH of the solution changes from 2 to 11 compared to changing the size from ~3 nm. Meanwhile, we found that quantum confinement is the dominant function for the optical spectroscopic results in the WX2-mQDs with a size of ~3 nm. This is because the oxidation of the larger WX2-mQDs induces sub-energy states, thus enabling excitons to migrate into the lower defect energy states, whereas in WX2-mQDs with a size comparable to the exciton Bohr radius, protonation enhances the quantum confinement.

17.
Plant Physiol ; 193(1): 661-676, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37348867

RESUMO

Plant cells can reprogram their fate. The combinatorial actions of auxin and cytokinin dedifferentiate somatic cells to regenerate organs, which can develop into individual plants. As transgenic plants can be generated from genetically modified somatic cells through these processes, cell fate transition is an unavoidable step in crop genetic engineering. However, regeneration capacity closely depends on the genotype, and the molecular events underlying these variances remain elusive. In the present study, we demonstrated that WUSCHEL (WUS)-a homeodomain transcription factor-determines regeneration capacity in different potato (Solanum tuberosum) genotypes. Comparative analysis of shoot regeneration efficiency and expression of genes related to cell fate transition revealed that WUS expression coincided with regeneration rate in different potato genotypes. Moreover, in a high-efficiency genotype, WUS silencing suppressed shoot regeneration. Meanwhile, in a low-efficiency genotype, regeneration could be enhanced through the supplementation of a different type of cytokinin that promoted WUS expression. Computational modeling of cytokinin receptor-ligand interactions suggested that the docking pose of cytokinins mediated by hydrogen bonding with the core residues may be pivotal for WUS expression and shoot regeneration in potatoes. Furthermore, our whole-genome sequencing analysis revealed core sequence variations in the WUS promoters that differentiate low- and high-efficiency genotypes. The present study revealed that cytokinin responses, particularly WUS expression, determine shoot regeneration efficiency in different potato genotypes.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Solanum tuberosum , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Proteínas de Homeodomínio/genética , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brotos de Planta/metabolismo , Citocininas/metabolismo , Genótipo , Regeneração/genética , Regulação da Expressão Gênica de Plantas , Meristema/genética
18.
Molecules ; 28(10)2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37241718

RESUMO

Periplasmic α-amylase MalS (EC. 3.2.1.1), which belongs to glycoside hydrolase (GH) family 13 subfamily 19, is an integral component of the maltose utilization pathway in Escherichia coli K12 and used among Ecnterobacteriaceae for the effective utilization of maltodextrin. We present the crystal structure of MalS from E. coli and reveal that it has unique structural features of circularly permutated domains and a possible CBM69. The conventional C-domain of amylase consists of amino acids 120-180 (N-terminal) and 646-676 (C-terminal) in MalS, and the whole domain architecture shows the complete circular permutation of C-A-B-A-C in domain order. Regarding substrate interaction, the enzyme has a 6-glucosyl unit pocket binding it to the non-reducing end of the cleavage site. Our study found that residues D385 and F367 play important roles in the preference of MalS for maltohexaose as an initial product. At the active site of MalS, ß-CD binds more weakly than the linear substrate, possibly due to the positioning of A402. MalS has two Ca2+ binding sites that contribute significantly to the thermostability of the enzyme. Intriguingly, the study found that MalS exhibits a high binding affinity for polysaccharides such as glycogen and amylopectin. The N domain, of which the electron density map was not observed, was predicted to be CBM69 by AlphaFold2 and might have a binding site for the polysaccharides. Structural analysis of MalS provides new insight into the structure-evolution relationship in GH13 subfamily 19 enzymes and a molecular basis for understanding the details of catalytic function and substrate binding of MalS.


Assuntos
Glicosídeo Hidrolases , alfa-Amilases , alfa-Amilases/metabolismo , Glicosídeo Hidrolases/metabolismo , Escherichia coli/metabolismo , Sequência de Aminoácidos , Amilases/metabolismo , Especificidade por Substrato , Cristalografia por Raios X
19.
Molecules ; 28(8)2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37110788

RESUMO

In this study, we aimed to develop natural and/or functional materials with antioxidant and anti-inflammatory effects. We obtained extracts from natural plants through an oil and hot-water extraction process and prepared an extract composite of an effective unsaturated fatty acid complex (EUFOC). Furthermore, the antioxidant effect of the extract complex was evaluated, and the anti-inflammatory effect was explored by assessing its inhibitory effect on nitric oxide production through its HA-promoting effect. We conducted a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay to evaluate the cell viability of the EUFOC, and the results showed that EUFOC was not cytotoxic at the test concentrations. In addition, it showed no endogenous cytotoxicity in HaCaT (human keratinocyte) cells. The EUFOC showed excellent 1,1-diphenyl-2-picrylhydrazyl- and superoxide-scavenging abilities. Moreover, it exerted an inhibitory effect on NO production at concentrations that did not inhibit cell viability. The secretion of all the cytokines was increased by lipopolysaccharide (LPS) treatment; however, this was inhibited by the EUFOC in a concentration-dependent manner. In addition, hyaluronic acid content was markedly increased by the EUFOC in a dose-dependent manner. These results suggest that the EUFOC has excellent anti-inflammatory and antioxidant properties, and hence, it can be used as a functional material in various fields.


Assuntos
Antioxidantes , Ácido Hialurônico , Humanos , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Óxido Nítrico/metabolismo , Anti-Inflamatórios/farmacologia , Citocinas
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