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1.
Sci Rep ; 14(1): 19800, 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39191862

ABSTRACT

Waste oyster shells (WOS) have the potential to serve as a construction material, offering a sustainable alternative to traditional fine aggregates in the production of WOS concrete. This can play a critical role in reducing environmental issues resulting from the overexploitation of river sand and the haphazard disposal of WOS. Although existing research has predominantly focused on understanding the static mechanical characteristics of concrete when WOS is employed, the dynamic mechanical properties have still received less attention. To understand the impact of WOS as a substitute for fine aggregates on the dynamic mechanical properties of concrete, a series of tests employing Split Hopkinson Pressure Bar (SHPB) were carried out. The findings demonstrate that the peak stress and elastic modulus increase as the WOS substitution ratio (Sr) increases from 0 to 20% but exhibit an exponential decline as Sr increases from 20 to 100%. This response can be explained by the joint effects of the pore-filling effect caused by WOS sand and the increasing air content caused by WOS sand. As Sr increases from 0 to 20%, the pore-filling mechanism becomes predominant as the water absorption rate decreases slightly from 4.31 to 3.83%. However, for Sr increasing from 20 to 100%, the negative influence of the air content becomes the primary contributing factor, where the water absorption rate increases from 3.83 to 14.68%. Furthermore, under the same impact pressure, the concrete with Sr = 20% absorbed the most energy, providing the best dynamic mechanical performance. These findings highlight the potential use of WOS in concrete for improving its dynamic characteristics, promoting both sustainable construction and enhancing the material properties in impact-resistant structures.

2.
Food Chem ; 460(Pt 2): 140624, 2024 Dec 01.
Article in English | MEDLINE | ID: mdl-39089040

ABSTRACT

The ß-glucosidases known to improve tea aroma are all mesothermal enzymes, limiting their use under brewing conditions. Based on the properties analysis and molecular docking, the thermostable ß-glucosidase (TPG) from Thermotoga petrophlia showed potential to enhance tea aroma. Treatment by recombinant TPG at 90 °C, the floral, sweet and grassy notes of instant Oolong tea were increased, while the roasted, caramel and woody notes were decreased. The improved floral, sweet and grassy notes were related to increase releasing of benzyl alcohol (floral), geraniol (floral), (Z)-3-hexen-1-ol (grassy), benzaldehyde (sweet) and 1-hexanol (grassy) by TPG hydrolyzing of (Z)-3-hexenyl-ß-D-glucopyranoside, hexanyl-ß-D-glucopyranoside (HGP), benzyl-ß-D-glucopyranoside, prunasin and geranyl-ß-D-glucopyranoside (GGP), respectively. Although the catalytic efficiency of TGP to GGP was about twice that to HGP, HPG was more competitive than GGP when they mixed. Combined with microstructure analysis, the structure-function relationship of TPG-influencing tea aroma were understood. This study provided the method of how to mining new function of characterized ß-glucosidases, as well as a theoretical basis for the development of new tea products.


Subject(s)
Enzyme Stability , Odorants , Tea , beta-Glucosidase , beta-Glucosidase/chemistry , beta-Glucosidase/metabolism , Tea/chemistry , Odorants/analysis , Camellia sinensis/chemistry , Camellia sinensis/enzymology , Molecular Docking Simulation , Flavoring Agents/chemistry , Flavoring Agents/metabolism , Volatile Organic Compounds/chemistry , Volatile Organic Compounds/metabolism , Hot Temperature , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism
3.
Enzyme Microb Technol ; 180: 110484, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39079223

ABSTRACT

There has been ongoing interest in improving the efficiency of glycoside hydrolase for synthesizing glycoside compounds through protein engineering, given the potential applications of glycoside compounds. In this study, a strategy of modifying the substrate access tunnel was proposed to enhance the efficiency of reverse hydrolysis catalyzed by Aspergillus niger α-L-rhamnosidase. Analysis of the tunnel dynamics identified Tyr299 as a key modifiable residue in the substrate access tunnel. The location of Tyr299 was near the enzyme surface and at the outermost end of the substrate access tunnel, suggested its role in substrate recognition and throughput. Based on the properties of side chains, six mutants were designed and expressed by Pichia pastoris. Compared to WT, the reverse hydrolysis efficiencies of mutants Y299P and Y299W were increased by 21.3 % and 11.1 %, respectively. The calculation results of binding free energy showed that the binding free energy was inversely proportional to the reverse hydrolysis efficiency. Further, when binding free energy levels were comparable, the mutants with shorter side chains displayed a higher reverse hydrolysis efficiency. These results proved that substrate access tunnel modification was an effective method to improve the reverse hydrolysis efficacy of α-L-rhamnosidase and also provided new insights for modifying other glycoside hydrolases.


Subject(s)
Aspergillus niger , Glycoside Hydrolases , Protein Engineering , Aspergillus niger/enzymology , Aspergillus niger/genetics , Hydrolysis , Glycoside Hydrolases/genetics , Glycoside Hydrolases/metabolism , Glycoside Hydrolases/chemistry , Substrate Specificity , Fungal Proteins/genetics , Fungal Proteins/metabolism , Fungal Proteins/chemistry , Mutagenesis, Site-Directed , Kinetics , Recombinant Proteins/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/chemistry , Mutation , Models, Molecular , Saccharomycetales
4.
Int J Biol Macromol ; 277(Pt 2): 134174, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39084418

ABSTRACT

The GH78 α-L-rhamnosidase from Aspergillus tubingensis (AT-Rha) was proved to be a new clade of Aspergillus α-L-rhamnosidases in the previous study. A putative α-L-rhamnosidase from A. kawachii IFO 4308 (AK-Rha) has 92 % identity in amino acid sequence with AT-Rha. In this study, AK-Rha was expressed in P. pastoris and characterized. Similar to AT-rRha, the recombinant AK-Rha (AK-rRha) showed a narrow substrate specificity to naringin. Interestingly, the enzyme activity of AK-rRha was 0.816 U/mg toward naringin, significantly lower than 125.142 U/mg of AT-rRha. Their large differences in catalytic efficiency was mainly due to their differences in kcat values between AK-rRha (0.67 s-1) and AT-rRha (4.89 × 104 s-1). The molecular dynamics simulation exhibited that the overall conformation of AK-Rha was rigid and that of AT-Rha was flexible; the Loop Y-L located above the catalytic domain formed different steric hindrances to naringin, and interacted with the flavonoid matrices at different strengths. The polar solvation energy analysis implied that the glycosidic bond was more easily hydrolysed in AT-Rha. The comparative study verified that the main feature of AK-Rha and AT-Rha represented Aspergillus α-L-rhamnosidase was the narrow substrate specificity toward naringin, and provided an insight of the relationships between their catalytic abilities and structures.


Subject(s)
Aspergillus , Glycoside Hydrolases , Glycoside Hydrolases/chemistry , Glycoside Hydrolases/genetics , Glycoside Hydrolases/metabolism , Substrate Specificity , Aspergillus/enzymology , Aspergillus/genetics , Amino Acid Sequence , Molecular Dynamics Simulation , Flavanones/chemistry , Kinetics , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid
5.
Int J Biol Macromol ; 274(Pt 2): 133500, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38944071

ABSTRACT

In traditional Chinese medicine, Lycium barbarum is of rich medicinal value, and its polysaccharides are particularly interesting due to their significant pharmacological effects and potential health benefits. This study investigated the immunomodulatory effects of Lycium barbarum polysaccharides (LBPs) by examining their interaction with the TLR4/MD-2 complex and the impacts of gastrointestinal digestion on these interactions. We discovered that the affinity binding of LBPs for TLR4/MD-2 and their cytokine induction capability are influenced by molecular weight, with medium-sized LBPs (100-300 kDa) exhibiting stronger binding affinity and induction capability. Conversely, LBPs smaller than 10 kDa showed reduced activity. Additionally, the content of arabinose and galactose within the LBPs fractions was found to correlate positively with both receptor affinity and cytokine secretion. Simulated gastrointestinal digestion resulted in the degradation of LBPs into smaller fragments that are rich in glucose. Although these fragments exhibited decreased binding affinity to the TLR4/MD-2 complex, they maintained their activity to promote cytokine production. Our findings highlight the significance of molecular weight and specific monosaccharide composition in the immunomodulatory function of LBPs and emphasize the influence of gastrointestinal digestion on the effects of LBPs. This research contributes to a better understanding of the mechanisms underlying the immunomodulatory effects of traditional Chinese medicine polysaccharides and their practical application.


Subject(s)
Digestion , Drugs, Chinese Herbal , Molecular Weight , Toll-Like Receptor 4 , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/chemistry , Toll-Like Receptor 4/metabolism , Digestion/drug effects , Immunologic Factors/pharmacology , Immunologic Factors/chemistry , Humans , Cytokines/metabolism , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/drug effects , Animals , Lycium/chemistry , Mice , Monosaccharides/analysis , Monosaccharides/chemistry , Polysaccharides/pharmacology , Polysaccharides/chemistry
6.
FEBS J ; 291(18): 4076-4095, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38872483

ABSTRACT

Discoidin, CUB, LCCL domain-containing 2 (DCBLD2) is a type I transmembrane protein with a similar structure to neuropilin, which acts as a co-receptor for certain receptor tyrosine kinases (RTKs). The insulin receptor is an RTK and plays a critical role in endothelial cell function and glycolysis. However, how and whether DCBLD2 regulates insulin receptor activity in endothelial cells is poorly understood. Diabetes was induced through treatment of Dcbld2 global-genome knockout mice and endothelium-specific knockout mice with streptozotocin. Vascular ultrasound, vascular tension test, and hematoxylin and eosin staining were performed to assess endothelial function and aortic remodeling. Glycolytic rate assays, real-time PCR and western blotting were used to investigate the effects of DCBLD2 on glycolytic activity and insulin receptor (InsR)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in endothelial cells. Co-immunoprecipitation was used to assess the effects of DCBLD2 on insulin receptor endocytosis and recycling. Membrane and cytoplasmic proteins were isolated to determine whether DCBLD2 could affect the localization of the insulin receptor. We found that Dcbld2 deletion exacerbated endothelial dysfunction and vascular remodeling in diabetic mice. Both Dcbld2 knockdown and Dcbld2 deletion inhibited glycolysis and the InsR/PI3K/Akt signaling pathway in endothelial cells. Furthermore, Dcbld2 deletion inhibited insulin receptor recycling. Taken together, Dcbld2 deficiency exacerbated diabetic endothelial dysfunction and vascular remodeling by inhibiting the InsR/PI3K/Akt pathway in endothelial cells through the inhibition of Rab11-dependent insulin receptor recycling. Our data suggest that DCBLD2 is a potential therapeutic target for diabetes and cardiovascular diseases.


Subject(s)
Diabetes Mellitus, Experimental , Hyperglycemia , Mice, Knockout , Receptor, Insulin , Vascular Remodeling , Animals , Receptor, Insulin/metabolism , Receptor, Insulin/genetics , Mice , Hyperglycemia/metabolism , Hyperglycemia/genetics , Hyperglycemia/pathology , Vascular Remodeling/genetics , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/pathology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Humans , Signal Transduction , Male , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-akt/genetics , Glycolysis/genetics , Endocytosis/genetics , Gene Deletion , Mice, Inbred C57BL
7.
Pestic Biochem Physiol ; 201: 105848, 2024 May.
Article in English | MEDLINE | ID: mdl-38685210

ABSTRACT

Fusarium asiaticum is a destructive phytopathogenic fungus that causes Fusarium head blight of wheat (FHB), leading to serious yield and economic losses to cereal crops worldwide. Our previous studies indicated that target-site mutations (K216R/E, S217P/L, or E420K/G/D) of Type I myosin FaMyo5 conferred high resistance to phenamacril. Here, we first constructed one sensitive strain H1S and three point mutation resistant strains HA, HC and H1R. Then we conducted comparative transcriptome analysis of these F. asiaticum strains after 1 and 10 µg·mL-1 phenamacril treatment. Results indicated that 2135 genes were differentially expressed (DEGs) among the sensitive and resistant strains. The DEGs encoding ammonium transporter MEP1/MEP2, nitrate reductase, copper amine oxidase 1, 4-aminobutyrate aminotransferase, amino-acid permease inda1, succinate-semialdehyde dehydrogenase, 2, 3-dihydroxybenzoic acid decarboxylase, etc., were significantly up-regulated in all the phenamacril-resistant strains. Compared to the control group, a total of 1778 and 2097 DEGs were identified in these strains after 1 and 10 µg·mL-1 phenamacril treatment, respectively. These DEGs involved in 4-aminobutyrate aminotransferase, chitin synthase 1, multiprotein-bridging factor 1, transcriptional regulatory protein pro-1, amino-acid permease inda1, ATP-dependent RNA helicase DED1, acetyl-coenzyme A synthetase, sarcoplasmic/endoplasmic reticulum calcium ATPase 2, etc., showed significantly down-regulated expression in phenamacril-sensitive strain but not in resistant strains after phenamacril treatment. In addition, cyanide hydratase, mating-type protein MAT-1, putative purine nucleoside permease, plasma membrane protein yro2, etc., showed significantly co-down-regulated expression in all the strains after phenamacril treatment. Taken together, This study provides deep insights into the resistance regulation mechanism and the inhibitory effect of fungicide phenamacril and these new annotated proteins or enzymes are worth for the discovery of new fungicide targets.


Subject(s)
Drug Resistance, Fungal , Fungicides, Industrial , Fusarium , Fusarium/drug effects , Fusarium/genetics , Fungicides, Industrial/pharmacology , Drug Resistance, Fungal/genetics , Gene Expression Profiling , Transcriptome/drug effects , Gene Expression Regulation, Fungal/drug effects , Plant Diseases/microbiology , Fungal Proteins/genetics , Fungal Proteins/metabolism
8.
Adv Mater ; 36(25): e2400366, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38469896

ABSTRACT

Given the challenge of multidrug resistance in antibiotics, non-antibiotic-dependent antibacterial strategies show promise for anti-infective therapy. V2C MXene-based nanomaterials have demonstrated strong biocompatibility and photothermal conversion efficiency (PCE) for photothermal therapy (PTT). However, the limitation of V2C MXene's laser irradiation to the near-infrared region I (NIR-I) restricts tissue penetration, making it difficult to achieve complete bacterial eradication with single-effect therapeutic strategies. To address this, Pt nanoparticles (Pt NPs) are attached to V2C, forming artificial nanoplatforms (Pt@V2C). Pt@V2C exhibits enhanced PCE (59.6%) and a longer irradiation laser (NIR-II) due to the surface plasmon resonance effect of Pt NPs and V2C. Notably, Pt@V2C displays dual enzyme-like activity with chemodynamic therapy (CDT) and NIR-II enhanced dual enzyme-like activity. The biocatalytic mechanism of Pt@V2C is elucidated using density functional theory. In an in vivo animal model, Pt@V2C effectively eliminates methicillin-resistant Staphylococcus aureus from deep-seated tissues in subcutaneous abscesses and bacterial keratitis environments, accelerating abscess resolution and promoting wound and cornea healing through the synergistic effects of PTT/CDT. Transcriptomic analysis reveals that Pt@V2C targets inflammatory pathways, providing insight into its therapeutic mechanism. This study presents a promising therapeutic approach involving hyperthermia-amplified biocatalysis with Pt NPs and MXene nanocomposites.


Subject(s)
Anti-Bacterial Agents , Metal Nanoparticles , Methicillin-Resistant Staphylococcus aureus , Photothermal Therapy , Platinum , Platinum/chemistry , Metal Nanoparticles/chemistry , Metal Nanoparticles/therapeutic use , Animals , Methicillin-Resistant Staphylococcus aureus/drug effects , Mice , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Infrared Rays , Staphylococcal Infections/drug therapy
9.
Prep Biochem Biotechnol ; 54(9): 1116-1120, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38477625

ABSTRACT

α-L-rhamnosidase (Rha) is ubiquitous in nature and has high feasibility in the food and biotechnology industries. A green and environmentally friendly method was used to improve the activity of Rha. Here, we show that the effects of ultrasound treatment on the Rha. Ultrasonic treatment at 80 W for 10 min yielded the highest enzyme activity. Treatment increased enzyme activity by 26.3% and half-life by 124 min. Further, treatment increased the catalytic efficiency of Rha and increased the substrate conversion rate by 33.88%. These results demonstrate that ultrasound increases the catalytic activity and stability of Rha. Thus, ultrasonic treatment of Rha is cost-effective on the industrial scale.


Subject(s)
Glycoside Hydrolases , Glycoside Hydrolases/metabolism , Glycoside Hydrolases/chemistry , Enzyme Stability , Ultrasonic Waves , Sonication , Biocatalysis , Kinetics
10.
J Exp Clin Cancer Res ; 43(1): 46, 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38342894

ABSTRACT

BACKGROUND: Nasopharyngeal carcinoma (NPC) poses a significant health burden in specific regions of Asia, and some of NPC patients have bone metastases at the time of initial diagnosis. Bone metastasis can cause pathologic fractures and pain, reducing patients' quality of life, and is associated with worse survival. This study aims to unravel the complex role of insulin-like growth factor 1 receptor (IGF-1R) in NPC bone metastasis, offering insights into potential therapeutic targets. METHODS: We assessed IGF-1R expression in NPC cells and explored its correlation with bone metastasis. Experiments investigated the impact of osteoclast-secreted IGF-1 on the IGF-1R/AKT/S6 pathway in promoting NPC cell proliferation within the bone marrow. Additionally, the reciprocal influence of tumor-secreted Granulocyte-macrophage colony-stimulating factor (GM-CSF) on osteoclast differentiation and bone resorption was examined. The effects of IGF-1 neutralizing antibody, IGF-1R specific inhibitor (NVP-AEW541) and mTORC inhibitor (rapamycin) on nasopharyngeal carcinoma bone metastasis were also explored in animal experiments. RESULTS: Elevated IGF-1R expression in NPC cells correlated with an increased tendency for bone metastasis. IGF-1, secreted by osteoclasts, activated the IGF-1R/AKT/S6 pathway, promoting NPC cell proliferation in the bone marrow. Tumor-secreted GM-CSF further stimulated osteoclast differentiation, exacerbating bone resorption. The IGF-1 neutralizing antibody, NVP-AEW541 and rapamycin were respectively effective in slowing down the rate of bone metastasis and reducing bone destruction. CONCLUSION: The intricate interplay among IGF-1R, IGF-1, and GM-CSF highlights potential therapeutic targets for precise control of NPC bone metastasis, providing valuable insights for developing targeted interventions.


Subject(s)
Bone Neoplasms , Bone Resorption , Nasopharyngeal Neoplasms , Animals , Humans , Nasopharyngeal Carcinoma/pathology , Insulin-Like Growth Factor I/metabolism , Insulin-Like Growth Factor I/pharmacology , Insulin-Like Growth Factor I/therapeutic use , Osteoclasts/metabolism , Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology , Granulocyte-Macrophage Colony-Stimulating Factor/therapeutic use , Proto-Oncogene Proteins c-akt/metabolism , Quality of Life , Cell Line, Tumor , Nasopharyngeal Neoplasms/pathology , Sirolimus/pharmacology , Antibodies, Neutralizing
11.
Br J Cancer ; 130(5): 755-768, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38228715

ABSTRACT

BACKGROUND: Radiotherapy is a critical treatment modality for nasopharyngeal carcinoma (NPC). However, the mechanisms underlying radiation resistance and tumour recurrence in NPC remain incompletely understood. METHODS: Oxidised lipids were assessed through targeted metabolomics. Ferroptosis levels were evaluated using cell viability, clonogenic survival, lipid peroxidation, and transmission electron microscopy. We investigated the biological functions of glutathione S-transferase mu 3 (GSTM3) in cell lines and xenograft tumours. Co-immunoprecipitation, mass spectrometry, and immunofluorescence were conducted to explore the molecular mechanisms involving GSTM3. Immunohistochemistry was performed to investigate the clinical characteristics of GSTM3. RESULTS: Ionising radiation (IR) promoted lipid peroxidation and induced ferroptosis in NPC cells. GSTM3 was upregulated following IR exposure and correlated with IR-induced ferroptosis, enhancing NPC radiosensitivity in vitro and in vivo. Mechanistically, GSTM3 stabilised ubiquitin-specific peptidase 14 (USP14), thereby inhibiting the ubiquitination and subsequent degradation of fatty acid synthase (FASN). Additionally, GSTM3 interacted with glutathione peroxidase 4 (GPX4) and suppressed GPX4 expression. Combining IR treatment with ferroptosis inducers synergistically improved NPC radiosensitivity and suppressed tumour growth. Notably, a decrease in GSTM3 abundance predicted tumour relapse and poor prognosis. CONCLUSIONS: Our findings elucidate the pivotal role of GSTM3 in IR-induced ferroptosis, offering strategies for the treatment of radiation-resistant or recurrent NPC.


Subject(s)
Ferroptosis , Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Carcinoma/radiotherapy , Neoplasm Recurrence, Local , Radiation Tolerance , Fatty Acid Synthases , Nasopharyngeal Neoplasms/pathology , Glutathione Transferase , Ubiquitin Thiolesterase , Fatty Acid Synthase, Type I
12.
Protein Cell ; 15(2): 121-134, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-37470320

ABSTRACT

Continual evolution of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) virus has allowed for its gradual evasion of neutralizing antibodies (nAbs) produced in response to natural infection or vaccination. The rapid nature of these changes has incited a need for the development of superior broad nAbs (bnAbs) and/or the rational design of an antibody cocktail that can protect against the mutated virus strain. Here, we report two angiotensin-converting enzyme 2 competing nAbs-8H12 and 3E2-with synergistic neutralization but evaded by some Omicron subvariants. Cryo-electron microscopy reveals the two nAbs synergistic neutralizing virus through a rigorous pairing permitted by rearrangement of the 472-489 loop in the receptor-binding domain to avoid steric clashing. Bispecific antibodies based on these two nAbs tremendously extend the neutralizing breadth and restore neutralization against recent variants including currently dominant XBB.1.5. Together, these findings expand our understanding of the potential strategies for the neutralization of SARS-CoV-2 variants toward the design of broad-acting antibody therapeutics and vaccines.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Cryoelectron Microscopy , Antibodies, Neutralizing , Antibodies, Viral
13.
Sheng Wu Gong Cheng Xue Bao ; 39(11): 4593-4607, 2023 Nov 25.
Article in Chinese | MEDLINE | ID: mdl-38013186

ABSTRACT

The hydrolysis of xylo-oligosaccharides catalyzed by ß-xylosidase plays an important role in the degradation of lignocellulose. However, the enzyme is easily inhibited by its catalytic product xylose, which severely limits its application. Based on molecular docking, this paper studied the xylose affinity of Aspergillus niger ß-xylosidase An-xyl, which was significantly differentially expressed in the fermentation medium of tea stalks, through cloning, expression and characterization. The synergistic degradation effect of this enzyme and cellulase on lignocellulose in tea stems was investigated. Molecular docking showed that the affinity of An-xyl to xylose was lower than that of Aspergillus oryzae ß-xylosidase with poor xylose tolerance. The Ki value of xylose inhibition constant of recombinant-expressed An-xyl was 433.2 mmol/L, higher than that of most ß-xylosidases of the GH3 family. The Km and Vmax towards pNPX were 3.6 mmol/L and 10 000 µmol/(min·mL), respectively. The optimum temperature of An-xyl was 65 ℃, the optimum pH was 4.0, 61% of the An-xyl activity could be retained upon treatment at 65 ℃ for 300 min, and 80% of the An-xyl activity could be retained upon treatment at pH 2.0-8.0 for 24 h. The hydrolysis of tea stem by An-xyl and cellulase produced 19.3% and 38.6% higher reducing sugar content at 2 h and 4 h, respectively, than that of using cellulase alone. This study showed that the An-xyl mined from differential expression exhibited high xylose tolerance and higher catalytic activity and stability, and could hydrolyze tea stem lignocellulose synergistically, which enriched the resource of ß-xylosidase with high xylose tolerance, thus may facilitate the advanced experimental research and its application.


Subject(s)
Cellulases , Xylosidases , Aspergillus niger/genetics , Xylose/metabolism , Molecular Docking Simulation , Xylosidases/genetics , Tea , Hydrogen-Ion Concentration , Substrate Specificity
14.
Biomater Sci ; 11(21): 7132-7145, 2023 Oct 24.
Article in English | MEDLINE | ID: mdl-37706659

ABSTRACT

Synergistic chemo-phototherapy has offered tremendous potential in cancer treatment. Nevertheless, nanosystems usually suffer from the complexity of multicomponents (polymeric or inorganic materials), which results in carrier-related toxicity issues. Moreover, the GSH over-expression of tumor cells seriously compromises ROS therapeutic efficiency. Herein, we designed a self-delivered nanodrug via Cu(II) coordination-driven co-self-assembly of celastrol (CST, a chemo-drug with anti-angiogenesis activity) and indocyanine green (ICG, a photosensitizer) for synergistic chemo-phototherapy with GSH depletion. The nanodrug was further cloaked by an erythrocyte membrane (RBC) to prolong the circulation time. Within the tumor microenvironment, the nanodrug would be disassembled upon intracellular GSH triggering. Moreover, the released Cu(II) could efficiently deplete the GSH, thus damaging the ROS-scavenging system and amplifying the phototherapeutic efficiency upon laser irradiation. The in vivo experiments validated the highly effective accumulation at tumor sites, potent tumor growth inhibition, and inappreciable systemic toxicity. The tumor microenvironment-responsive coordination-driven self-assembled biomimetic nanodrug may hold potential applications in tumor theranostics.

15.
Brief Bioinform ; 24(5)2023 09 20.
Article in English | MEDLINE | ID: mdl-37595963

ABSTRACT

Alignment-based RNA-seq quantification methods typically involve a time-consuming alignment process prior to estimating transcript abundances. In contrast, alignment-free RNA-seq quantification methods bypass this step, resulting in significant speed improvements. Existing alignment-free methods rely on the Expectation-Maximization (EM) algorithm for estimating transcript abundances. However, EM algorithms only guarantee locally optimal solutions, leaving room for further accuracy improvement by finding a globally optimal solution. In this study, we present TQSLE, the first alignment-free RNA-seq quantification method that provides a globally optimal solution for transcript abundances estimation. TQSLE adopts a two-step approach: first, it constructs a k-mer frequency matrix A for the reference transcriptome and a k-mer frequency vector b for the RNA-seq reads; then, it directly estimates transcript abundances by solving the linear equation ATAx = ATb. We evaluated the performance of TQSLE using simulated and real RNA-seq data sets and observed that, despite comparable speed to other alignment-free methods, TQSLE outperforms them in terms of accuracy. TQSLE is freely available at https://github.com/yhg926/TQSLE.


Subject(s)
Algorithms , Transcriptome , RNA-Seq , Sequence Analysis, RNA/methods , Software , Gene Expression Profiling/methods
16.
Prospects (Paris) ; : 1-19, 2023 Mar 12.
Article in English | MEDLINE | ID: mdl-37360046

ABSTRACT

This research is based on an approach that looks at cross-cultural research design as a "lens" for a deeper understanding of what goes on in the classroom. The research question is how a cross-cultural study like this one can lead to identifying the cultural script of teaching and help educators reflect on their practice. In this context, Chinese lessons could be described as a case-based study of pedagogical reasoning that drives a shift from focusing on "content" to "competence". This article draws on qualitative data collected by the researchers and a cross-cultural analysis of a science lesson in an elementary school in Beijing, China. Using the Japanese educators' critiques and Chinese reviews, the article determines the cultural script of teaching science (the first research question) and the way Chinese teachers reflect on their practice through the Japanese lens (the second research question). This study exposes the importance of teachers' understanding and reflecting on their practice, technically, practically, and critically. The analysis results show how teachers learn to change their lenses, to reflect on their teaching and reconstruct their understanding about teacher professionalism through at least four basic elements: didactics, praxis, pedagogy, and theory.

17.
Reprod Biol Endocrinol ; 21(1): 59, 2023 Jun 27.
Article in English | MEDLINE | ID: mdl-37370122

ABSTRACT

OBJECTIVE: This study aimed to explore the optimal time of laparoscopic cystectomy for unilateral ovarian endometrioma patients and evaluate the influence on ovarian reserve. MATERIALS AND METHODS: This prospective randomized controlled study included 88 women with unilateral ovarian endometrioma at a tertiary teaching hospital. All patients received their first identified diagnosis of ovarian endometrioma by ultrasound (> 4 cm and ≤ 10 cm) and were administered an oral contraceptive pill (OC) for one cycle before laparoscopy. They were randomly divided into two groups: laparoscopy at the late luteal phase (group LLP) (n = 44) (termination of OC for two days) and laparoscopy at the early follicular phase (group EFP) (n = 44) (day 3 after menstruation). Basic clinical characteristics were recorded. Serum Anti-Müllerian hormone (AMH) levels were measured at various times to predict ovarian reserve. Serum levels of Anti-Müllerian hormone (AMH) were measured at several time sites to predict the ovarian reserve; AMH and leukocyte esterase (LE) levels of the endometrioma wall were measured. RESULTS: Before surgery, serum AMH levels decreased in both groups from preoperative to one week and six months postoperatively. In contrast, the difference values of group EFP were larger than those of group LLP at postoperative one week and postoperative six months (1.87 ± 0.97 vs. 1.31 ± 0.93, P = 0.07; 1.91 ± 1.06 vs. 1.54 ± 0.93, P = 0.001). The mean rates of postoperative serum AMH decline were 37.92% and 46.34% in group EFP, significantly higher than those in group LLP (25.83% vs. 31.43%, P < 0.001). Ovarian endometrioma wall AMH of group LLP was significantly lower than that of group EFP ([22.86 ± 3.74] vs. [31.02 ± 5.23], P < 0.001). Meanwhile, ovarian endometrioma LE concentration of group LLP was significantly higher than that of group EFP ([482.83 ± 115.88] vs. [371.68 ± 84.49], P<0.001). There was also a significant inverse correlation between leukocyte esterase and AMH concentration in an ovarian endometrioma cyst wall (r=-0.564, P<0.001). CONCLUSION(S): The optimal time for laparoscopic cystectomy for patients with first identified unilateral ovarian endometrioma is the late luteal phase, which reduces ovarian tissue loss and preserves ovarian reserve effectively and safely.


Subject(s)
Endometriosis , Laparoscopy , Ovarian Cysts , Ovarian Reserve , Humans , Female , Endometriosis/surgery , Prospective Studies , Anti-Mullerian Hormone , Ultrasonography , Ovarian Cysts/surgery , Ovarian Cysts/diagnosis
18.
Food Funct ; 14(10): 4921-4930, 2023 May 22.
Article in English | MEDLINE | ID: mdl-37158134

ABSTRACT

Despite their important bioactivities, the unpleasant bitter taste of citrus derived flavonoids limits their applications in the food industry, and the structure-bitterness relationship of flavonoids is still far from clear. In this study, 26 flavonoids were characterized by their bitterness threshold and their common skeleton using sensory evaluation and molecular superposition, respectively. The quantitative conformational relationship of the structure-bitterness of flavonoids was explored using 3D-QSAR based on comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA). The results showed that increases of a hydrogen bond donor at A-5 or B-3', a bulky group at A-8, or an electron-withdrawing group at B-4' would enhance the bitterness of flavonoids. The bitterness of some flavonoids was predicted and evaluated, and the results were similar to the bitter intensity of the counterparts from the 3D-QSAR and contour plots, confirming the validation of 3D-QSAR. This study explains the theory of the structure-bitterness relationship of flavonoids, by showing potential information for understanding the bitterness in citrus flavonoids and developing a debittering process.


Subject(s)
Flavonoids , Quantitative Structure-Activity Relationship , Flavonoids/chemistry , Taste , Models, Molecular , Molecular Conformation
19.
Biomolecules ; 13(4)2023 04 09.
Article in English | MEDLINE | ID: mdl-37189408

ABSTRACT

Skin cutaneous melanoma (SKCM) is a highly malignant and aggressive cancer. Previous studies have shown that cellular senescence is a promising therapeutic strategy to limit melanoma cell progression. However, models to predict the prognosis of melanoma based on senescence-related lncRNAs and the efficacy of immune checkpoint therapy remain undefined. In this study, we developed a predictive signature consisting of four senescence-related lncRNAs (AC009495.2, U62317.1, AATBC, MIR205HG), and we then classified patients into high- and low-risk groups. GSEA (Gene set enrichment analysis) showed different activation of immune-related pathways in two groups. In addition, there were significant differences between the scores of tumor immune microenvironment, tumor burden mutation, immune checkpoint expression, and chemotherapeutic drug sensitivity between the two groups of patients. It provides new insights to guide more personalized treatment for patients with SKCM.


Subject(s)
Melanoma , RNA, Long Noncoding , Skin Neoplasms , Humans , Melanoma/drug therapy , Melanoma/genetics , Skin Neoplasms/drug therapy , Skin Neoplasms/genetics , RNA, Long Noncoding/genetics , Immunotherapy , Tumor Microenvironment/genetics , Melanoma, Cutaneous Malignant
20.
Mikrochim Acta ; 190(6): 216, 2023 05 13.
Article in English | MEDLINE | ID: mdl-37173548

ABSTRACT

Magnetic nanomaterials are widely used, but co-adsorption of impurities will lead to saturation. In this study, the aim was to prepare a magnetic nano-immunosorbent material based on orienting immobilization that can purify and separate 25-hydroxyvitamin D (25OHD) from serum and provides a new concept of sample pretreatment technology. Streptococcus protein G (SPG) was modified on the surface of the chitosan magnetic material, and the antibody was oriented immobilized using the ability of SPG to specifically bind to the Fc region of the monoclonal antibody. The antigen-binding domain was fully exposed and made up for the deficiency of the antibody random immobilization. Compared with the antibody in the random binding format, this oriented immobilization strategy can increase the effective activity of the antibody, and the amount of antibody consumed is saved to a quarter of the former. The new method is simple, rapid, and sensitive, without consuming a lot of organic reagents, and can enrich 25OHD after simple protein precipitation. Combining with liquid chromatography-tandem mass spectrometry (LC-MS/MS), the analysis can be completed in less than 30 min. For 25OHD2 and 25OHD3, the LOD was 0.021 and 0.017 ng mL-1, respectively, and the LOQ was 0.070 and 0.058 ng mL-1, respectively. The results indicated that the magnetic nanomaterials based on oriented immobilization can be applied as an effective, sensitive, and attractive adsorbent to the enrichment of serum 25OHD.


Subject(s)
Calcifediol , Tandem Mass Spectrometry , Chromatography, Liquid/methods , Tandem Mass Spectrometry/methods , Antibodies, Monoclonal , Magnetic Phenomena
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