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1.
Nanoscale ; 16(12): 6199-6214, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38446101

RESUMO

While the filtering and accumulation effects of the extracellular matrix (ECM) on nanoparticles (NPs) have been experimentally observed, the detailed interactions between NPs and specific biomolecules within the ECM remain poorly understood and pose challenges for in vivo molecular-level investigations. Herein, we adopt molecular dynamics simulations to elucidate the impacts of methyl-, hydroxy-, amine-, and carboxyl-modified gold NPs on the cell-binding domains of fibronectin (Fn), an indispensable component of the ECM for cell attachment and signaling. Simulation results show that NPs can specifically bind to distinct Fn domains, and the strength of these interactions depends on the physicochemical properties of NPs. NP-NH3+ exhibits the highest affinity to domains rich in acidic residues, leading to strong electrostatic interactions that induce severe deformation, potentially disrupting the normal functioning of Fn. NP-CH3 and NP-COO- selectively occupy the RGD/PHSRN motifs, which may hinder their recognition by integrins on the cell surface. Additionally, NPs can disrupt the dimerization of Fn through competing for residues at the dimer interface or by diminishing the shape complementarity between dimerized proteins. The mechanical stretching of Fn, crucial for ECM fibrillogenesis, is suppressed by NPs due to their local rigidifying effect. These results provide valuable molecular-level insights into the impacts of various NPs on the ECM, holding significant implications for advancing nanomedicine and nanosafety evaluation.


Assuntos
Fibronectinas , Nanopartículas , Fibronectinas/química , Integrinas/metabolismo , Matriz Extracelular/metabolismo , Transdução de Sinais
2.
Int J Biol Macromol ; 265(Pt 1): 130855, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38490377

RESUMO

Transient receptor potential canonical (TRPC) channels allow the intracellular entry of Ca2+ and play important roles in several physio-pathological processes. In this study, we constructed transgenic mice expressing porcine TRPC1 (Tg-pTRPC1) to verify the effects of TRPC1 on skeletal muscle growth and elucidate the underlying mechanism. Porcine TRPC1 increased the muscle mass, fiber cross-sectional area, and exercise endurance of mice and accelerated muscle repair and regeneration. TRPC1 overexpression enhanced ß-catenin expression and promoted myogenesis, which was partly reversed by inhibitors of ß-catenin. TRPC1 facilitated the accumulation of intracellular Ca2+ and nuclear translocation of the NFATC2/NFATC2IP complex involved in the Wnt/Ca2+ pathway, promoting muscle growth. Paired related homeobox 1 (Prrx1) promoted the expression of TRPC1, NFATC2, and NFATC2IP that participate in the regulation of muscle growth. Taken together, our findings indicate that porcine TRPC1 promoted by Prrx1 could regulate muscle development through activating the canonical Wnt/ß-catenin and non-canonical Wnt/Ca2+ pathways.


Assuntos
Canais de Potencial de Receptor Transitório , beta Catenina , Camundongos , Animais , Suínos , beta Catenina/genética , beta Catenina/metabolismo , Músculo Esquelético/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Ligação a DNA/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Cálcio/metabolismo , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/metabolismo
3.
BMC Med Genomics ; 17(1): 55, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378613

RESUMO

BACKGROUND: Gene variants are responsible for more than half of hearing loss, particularly in nonsyndromic hearing loss (NSHL). The most common pathogenic variant in SLC26A4 gene found in East Asian populations is c.919-2A > G followed by c.2168A > G (p.H723R). This study was to evaluate their variant frequencies in patients with NSHL from special education schools in nine different areas of Southwest China's Yunnan. METHODS: We performed molecular characterization by PCR-products directly Sanger sequencing of the SLC26A4 c.919-2AG and c.2168 A > G variants in 1167 patients with NSHL including 533 Han Chinese and 634 ethnic minorities. RESULTS: The SLC26A4 c.919-2A > G variant was discovered in 8 patients with a homozygous state (0.69%) and twenty-five heterozygous (2.14%) in 1167 patients with NSHL. The total carrier rate of the c.919-2A > G variant was found in Han Chinese patients with 4.50% and ethnic minority patients with 1.42%. A significant difference existed between the two groups (P < 0.05). The c.919-2A > G allele variant frequency was ranged from 3.93% in Kunming to zero in Lincang and Nvjiang areas of Yunnan. We further detected the SLC26A4 c.2168 A > G variant in this cohort with one homozygotes (0.09%) and seven heterozygotes (0.60%), which was detected in Baoshan, Honghe, Licang and Pu`er areas. Between Han Chinese group (0.94%) and ethnic minority group (0.47%), there was no statistical significance (P > 0.05). Three Han Chinese patients (0.26%) carried compound heterozygosity for c.919-2A > G and c.2168 A > G. CONCLUSION: These data suggest that the variants in both SLC26A4 c.919-2A > G and c.2168 A > G were relatively less frequencies in this cohort compared to the average levels in most regions of China, as well as significantly lower than that in Han-Chinese patients. These results broadened Chinese population genetic information resources and provided more detailed information for regional genetic counselling for Yunnan.


Assuntos
Surdez , Etnicidade , Proteínas de Membrana Transportadoras , Humanos , Etnicidade/genética , Mutação , Proteínas de Membrana Transportadoras/genética , Grupos Minoritários , China/epidemiologia , Conexinas/genética , Transportadores de Sulfato/genética
4.
JACS Au ; 4(1): 164-176, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38274262

RESUMO

Dpp-imines are classic model substrates for synthetic method studies. Here, we disclose their powerful use as achiral coligands in metal-catalyzed reactions. It is highly interesting to find that the Dpp-imine can not only act as powerful ligand to create excellent chiral pockets with magnesium complexes but also, more importantly, this coligand can dramatically enhance the catalytic ability of the metal catalyst. The underlying reaction mechanism was extensively explored by conducting a series of experiments, including 31P NMR studies of the coordination complex between the Dpp-imine coligand and magnesium complexes, ESI capture results, multiple control experiments, studies and comparison of different coligands, 1H NMR studies on the relationship between the substrate and Dpp-imine coligand, as well as the relationship between the substrate and the full complexes. Furthermore, DFT calculation provided valuable insights in the role of the imine additive and demonstrated that adding the Dpp-imine coligand in the magnesium catalyst can switch the deprotonation/nucleophilic addition steps from a stepwise mechanism to a concerted process during the oxa-cyclization reaction. The crucial factors responsible for the excellent enantioselectivity and enhanced reaction efficiency brought by Dpp-imine have been extracted from the calculation model. These mechanistic experiments and DFT calculation data clearly disclose and prove the powerful and interesting functions of the Dpp-imine coligand, which also direct a novel application of this type of active imine as useful ligands in metal-catalyzed asymmetric reactions.

5.
Small ; : e2310234, 2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38155520

RESUMO

The development of chiral nanostructures-based supramolecular catalysts with satisfied enantioselectivity remains a significantly more challenging task. Herein, the synthesis and self-assembly of various amino acid amphiphiles as chiral supramolecular catalysts after metal ion coordination is reported and systematically investigate their enantioselectivity in asymmetric Diels-Alder reactions. In particular, the self-assembly of l/d-phenylglycine-based amphiphiles (l/d-PhgC16 ) and Cu(II) into chiral supramolecular catalysts in the methanol/water solution mixture is described, which features the interesting M/P nanohelices (diameter ≈8 nm) and mostly well-aligned M/P nanoribbons (NRs). The M/P supramolecular catalysts show both high but inverse enantioselectivity (>90% ee) in Diels-Alder reactions, while their monomeric counterparts display nearly racemic products. Analysis of the catalytic results suggests the outstanding enantioselectivities are closely related to the specific stereochemical microenvironment provided by the arrangement of the amphiphiles in the supramolecular assembly. Based on the experimental evidence of chirality transfer from supramolecular nanohelices to coordinated Cu(II) and substrate aza-chalcone and the molecular dynamics simulations, the enantioselective catalytic mechanisms are proposed. Moreover, the relationships between molecular structures of amino acid amphiphiles (the hydrophilic head group and hydrophobic alkyl chain length) in supramolecular catalysts and enantioselectivity in Diels-Alder reactions are elaborated.

6.
Artigo em Inglês | MEDLINE | ID: mdl-37983718

RESUMO

Colorectal cancer (CRC) is a common and lethal cancer. ZNF687 has been disclosed to take part in diversified cancers' progression by serving as a facilitator. However, the detailed regulatory functions of ZNF687 in the CRC have not been investigated. This work is planned to probe the impacts of ZNF687 on CRC progression. The IHC, RT-qPCR, and western blot assays were used to examine mRNA and protein gene expressions. The cell proliferation measurement was accompanied by a CCK-8 assay. The Transwell assay was performed to evaluate cell invasion and migration. The angiogenesis ability was evaluated by a tube formation experiment. The m6A level was evaluated through MeRIP and m6A dot blot assays. The binding ability between ZNF687 and FTO (fat mass and obesity associated protein) was tested through an RIP assay. The ß-catenin nuclear translocation was assessed through an immunofluorescence assay. The tumor growth was evaluated through an in vivo assay. ZNF687 exhibited higher expression in CRC cells and resulted in a poor prognosis. Additionally, ZNF687 inhibition suppressed CRC cell proliferation, invasion, migration, and angiogenesis. Furthermore, the suppression of ZNF687 retarded the Wnt pathway. Through rescue assays, the reduced cell migration, proliferation, invasion, and angiogenesis mediated by ZNF687 knockdown could be reversed after BML-284 (the activator of the Wnt pathway) treatment. Finally, it was explained that ZNF687 knockdown inhibited in vivo tumor growth. This study manifested that FTO-mediated ZNF687 aggravated tumor growth, metastasis, and angiogenesis of CRC through Wnt/ß-catenin pathway. This finding may provide a hopeful molecular target for CRC treatment.

7.
Nat Commun ; 14(1): 6680, 2023 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-37865661

RESUMO

Biosensors are powerful tools for detecting, real-time imaging, and quantifying molecules, but rapidly constructing diverse genetically encoded biosensors remains challenging. Here, we report a method to rapidly convert enzymes into genetically encoded circularly permuted fluorescent protein-based indicators to detect organic acids (GECFINDER). ANL superfamily enzymes undergo hinge-mediated ligand-coupling domain movement during catalysis. We introduce a circularly permuted fluorescent protein into enzymes hinges, converting ligand-induced conformational changes into significant fluorescence signal changes. We obtain 11 GECFINDERs for detecting phenylalanine, glutamic acid and other acids. GECFINDER-Phe3 and GECFINDER-Glu can efficiently and accurately quantify target molecules in biological samples in vitro. This method simplifies amino acid quantification without requiring complex equipment, potentially serving as point-of-care testing tools for clinical applications in low-resource environments. We also develop a GECFINDER-enabled droplet-based microfluidic high-throughput screening method for obtaining high-yield industrial strains. Our method provides a foundation for using enzymes as untapped blueprint resources for biosensor design, creation, and application.


Assuntos
Aminoácidos , Técnicas Biossensoriais , Ligantes , Proteínas/química , Fenilalanina , Técnicas Biossensoriais/métodos
8.
Anal Bioanal Chem ; 415(29-30): 7127-7138, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37770666

RESUMO

A novel deep learning-enabled smartphone platform is developed to assist a colorimetric aptamer biosensor for fast and highly sensitive detection of dimethoate. The colorimetric determination of dimethoate is based on the specific binding of dimethoate and aptamer, which leads to the aggregation of AuNPs in high-concentration NaCl solution, resulting in an obvious color change from red to blue. This color change provides sufficient data for self-learning enabled by a convolutional neural network (CNN) model, which is established to predict dimethoate concentration based on images acquired from a smartphone. To enhance user-friendliness for non-experts, the CNN model is then embedded into a smartphone app, enabling offline detection of dimethoate pesticide in real environments within just 15 min using a pre-configured colorimetric probe. The developed platform exhibits superior performance, achieving a regression coefficient of 0.9992 in the concentration range of 0-10 µM. Moreover, the app's performance is found to be consistent with the ELISA kit. These remarkable findings demonstrate the potential of combining colorimetric biosensors with smartphone-based deep learning methods for the development of portable and affordable tools for pesticide detection.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Aprendizado Profundo , Nanopartículas Metálicas , Praguicidas , Colorimetria/métodos , Dimetoato , Smartphone , Ouro , Limite de Detecção , Técnicas Biossensoriais/métodos
9.
Small ; 19(47): e2303739, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37507827

RESUMO

Understanding origin of asymmetric information encoded on chiral nanozymes is important in mediating enantioselective catalysis. Herein, the supramolecular chiral nanozymes constructed from P/M-polyaniline (P/M-PANI) nanotwists and metal ions (M2+ , M = Cu, Ni, Co, and Zn) are designed through thioglycolic acid (TA) without chiral molecules to show the regulated catalytic efficiency and enantioselectivity. With combination of chiral environment from supramolecular scaffolds and catalytic center from metal ions, the P-PANI-TA-M2+ as nanozymes show preference to 3,4-dihydroxy-S-phenylalanine (S-DOPA) oxidation while the M-PANI-TA-M2+ show better selectivity to R-DOPA oxidation. Among them, though the Cu2+ doped supramolecular nanotwists show the highest catalytic efficiency, the Co2+ doped ones with moderate catalytic efficiency can exhibit the best enantioselectivity with select factor as high as 2.07. The molecular dynamic (MD) simulation clarifies the mechanism of enantioselective catalysis caused by the differential kinetics with S/R-DOPA enantiomers adsorbed on chiral PANI surface and free in solution. This work systematically studies the synergistic effect between the chiral supramolecular nanostructures assembled by achiral species and metal ions as peroxidase-like catalytic centers to regulate the enantioselectivity, providing deep understanding of the origin of asymmetric catalysis and serving as strong foundation to guide the design of nanozymes with high enantioselectivity.


Assuntos
Di-Hidroxifenilalanina , Metais , Estereoisomerismo , Catálise , Íons
10.
Toxins (Basel) ; 15(6)2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37368682

RESUMO

Fusarium wilt, caused by Fusarium oxysporum, is one of the most notorious diseases of cash crops. The use of microbial fungicides is an effective measure for controlling Fusarium wilt, and the genus Bacillus is an important resource for the development of microbial fungicides. Fusaric acid (FA) produced by F. oxysporum can inhibit the growth of Bacillus, thus affecting the control efficacy of microbial fungicides. Therefore, screening FA-tolerant biocontrol Bacillus may help to improve the biocontrol effect on Fusarium wilt. In this study, a method for screening biocontrol agents against Fusarium wilt was established based on tolerance to FA and antagonism against F. oxysporum. Three promising biocontrol bacteria, named B31, F68, and 30833, were obtained to successfully control tomato, watermelon, and cucumber Fusarium wilt. Strains B31, F68, and 30833 were identified as B. velezensis by phylogenetic analysis of the 16S rDNA, gyrB, rpoB, and rpoC gene sequences. Coculture assays revealed that strains B31, F68, and 30833 showed increased tolerance to F. oxysporum and its metabolites compared with B. velezensis strain FZB42. Further experiments confirmed that 10 µg/mL FA completely inhibited the growth of strain FZB42, while strains B31, F68, and 30833 maintained normal growth at 20 µg/mL FA and partial growth at 40 µg/mL FA. Compared with strain FZB42, strains B31, F68, and 30833 exhibited significantly greater tolerance to FA.


Assuntos
Bacillus , Fungicidas Industriais , Fusarium , Fusarium/metabolismo , Ácido Fusárico/farmacologia , Ácido Fusárico/metabolismo , Fungicidas Industriais/farmacologia , Filogenia , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia , Bacillus/genética
11.
J Hazard Mater ; 457: 131825, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37315410

RESUMO

Extracellular polymeric substances (EPS) represent an interface between microbial cells and aquatic environment, where nanoplastics acquire coatings to alter their fate and toxicity. However, little is known about molecular interactions governing modification of nanoplastics at biological interfaces. Molecular dynamics simulations combining experiments were conducted to investigate assembly of EPS and its regulatory roles in the aggregation of differently charged nanoplastics and interactions with bacterial membrane. Driven by hydrophobic and electrostatic interactions, EPS formed micelle-like supramolecular structures with hydrophobic core and amphiphilic exterior. Different components, depending on their hydrophobicity and charge, were found to promote or suppress EPS assembly. Neutral and hydrophobic nanoplastics showed unbiased adsorption of EPS species, while cationic and anionic nanoplastics were distinct and attracted specific molecules of opposite charges. Compared with isolated EPS, assembled EPS concealed hydrophobic groups to be less adsorbed by nanoplastics. Aggregation of nanoplastics was alleviated by EPS due to electrostatic repulsion plus steric hindrance. ESP suppressed binding of cationic nanoplastics to the bacterial membrane through reducing the surface charge. Neutral and anionic nanoplastics showed weak membrane association, but their binding interactions were promoted by EPS. The structural details revealed here provided molecular level insights into modifications of nanoplastics at the eco-environment interface.


Assuntos
Matriz Extracelular de Substâncias Poliméricas , Microplásticos , Matriz Extracelular de Substâncias Poliméricas/química , Microplásticos/análise , Adsorção , Interações Hidrofóbicas e Hidrofílicas
12.
Life Sci Alliance ; 6(9)2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37339805

RESUMO

Monosodium uric acid (MSU) crystal, the etiological agent of gout, has been shown to trigger innate immune responses via multiple pathways. It is known that MSU-induced lipid sorting on plasma membrane promotes the phosphorylation of Syk and eventually leads to the activation of phagocytes. However, whether this membrane lipid-centric mechanism is regulated by other processes is unclear. Previous studies showed that Clec12a, a member of the C-type lectin receptor family, is reported to recognize MSU and suppresses this crystalline structure-induced immune activation. How this scenario is integrated into the lipid sorting-mediated inflammatory responses by MSU, and particularly, how Clec12a intercepts lipid raft-originated signaling cascade remains to be elucidated. Here, we found that the ITIM motif of Clec12a is dispensable for its inhibition of MSU-mediated signaling; instead, the transmembrane domain of Clec12a disrupts MSU-induced lipid raft recruitment and thus attenuates downstream signals. Single amino acid mutagenesis study showed the critical role of phenylalanine in the transmembrane region for the interactions between C-type lectin receptors and lipid rafts, which is critical for the regulation of MSU-mediated lipid sorting and phagocyte activation. Overall, our study provides new insights for the molecular mechanisms of solid particle-induced immune activation and may lead to new strategies in inflammation control.


Assuntos
Gota , Ácido Úrico , Humanos , Ácido Úrico/metabolismo , Ácido Úrico/farmacologia , Gota/metabolismo , Inflamação/metabolismo , Imunidade Inata , Lipídeos
13.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 35(6): 633-637, 2023 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-37366131

RESUMO

OBJECTIVE: To investigate whether hydrogen-rich water exerts a protective effect against cellular injury by affecting the level of autophagy after oxygen glucose deprivation/reoxygenation (OGD/R) in a mouse hippocampal neuronal cell line (HT22 cells). METHODS: HT22 cells in logarithmic growth phase were cultured in vitro. Cell viability was detected by cell counting kit-8 (CCK-8) assay to find the optimal concentration of Na2S2O4. HT22 cells were divided into control group (NC group), OGD/R group (sugar-free medium+10 mmol/L Na2S2O4 treated for 90 minutes and then changed to normal medium for 4 hours) and hydrogen-rich water treatment group (HW group, sugar-free medium+10 mmol/L Na2S2O4 treated for 90 minutes and then changed to medium containing hydrogen-rich water for 4 hours). The morphology of HT22 cells was observed by inverted microscopy; cell activity was detected by CCK-8 method; cell ultrastructure was observed by transmission electron microscopy; the expression of microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 was detected by immunofluorescence; the protein expression of LC3II/I and Beclin-1, markers of cellular autophagy, was detected by Western blotting. RESULTS: Inverted microscopy showed that compared with the NC group, the OGD/R group had poor cell status, swollen cytosol, visible cell lysis fragments and significantly lower cell activity [(49.1±2.7)% vs. (100.0±9.7)%, P < 0.01]; compared with the OGD/R group, the HW group had improved cell status and remarkably higher cell activity [(63.3±1.8)% vs. (49.1±2.7)%, P < 0.01]. Transmission electron microscopy showed that the neuronal nuclear membrane of cells in the OGD/R group was lysed and a higher number of autophagic lysosomes were visible compared with the NC group; compared with the OGD/R group, the neuronal damage of cells in the HW group was reduced and the number of autophagic lysosomes was notably decreased. The results of immunofluorescence assay showed that the expressions of LC3 and Beclin-1 were outstandingly enhanced in the OGD/R group compared with the NC group, and the expressions of LC3 and Beclin-1 were markedly weakened in the HW group compared with the OGD/R group. Western blotting assay showed that the expressions were prominently higher in both LC3II/I and Beclin-1 in the OGD/R group compared with the NC group (LC3II/I: 1.44±0.05 vs. 0.37±0.03, Beclin-1/ß-actin: 1.00±0.02 vs. 0.64±0.01, both P < 0.01); compared with the OGD/R group, the protein expression of both LC3II/I and Beclin-1 in the HW group cells were notably lower (LC3II/I: 0.54±0.02 vs. 1.44±0.05, Beclin-1/ß-actin: 0.83±0.07 vs. 1.00±0.02, both P < 0.01). CONCLUSIONS: Hydrogen-rich water has a significant protective effect on OGD/R-causing HT22 cell injury, and the mechanism may be related to the inhibition of autophagy.


Assuntos
Oxigênio , Traumatismo por Reperfusão , Camundongos , Animais , Oxigênio/metabolismo , Proteína Beclina-1/farmacologia , Glucose/metabolismo , Actinas , Autofagia/fisiologia , Hidrogênio/farmacologia , Apoptose
14.
Nanomaterials (Basel) ; 13(11)2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37299612

RESUMO

FinFET devices and Silicon-On-Insulator (SOI) devices are two mainstream technical routes after the planar MOSFET reached the limit for scaling. The SOI FinFET devices combine the benefits of FinFET and SOI devices, which can be further boosted by SiGe channels. In this work, we develop an optimizing strategy of the Ge fraction in SiGe Channels of SGOI FinFET devices. The simulation results of ring oscillator (RO) circuits and SRAM cells reveal that altering the Ge fraction can improve the performance and power of different circuits for different applications.

15.
ACS Synth Biol ; 12(6): 1761-1771, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37198736

RESUMO

Genetically encoded biosensors are powerful tools for product-driven high-throughput screening in synthetic biology and metabolic engineering. However, most biosensors can only properly function in a limited concentration cutoff, and the incompatible performance characteristics of biosensors will lead to false positives or failure in screening. The transcription factor (TF)-based biosensors are usually organized in modular architecture and function in a regulator-depended manner, whose performance properties can be fine-tuned by modifying the expression level of the TF. In this study, we modulated the performance characteristics, including sensitivity and operating range, of an MphR-based erythromycin biosensor by fine-adjusting regulator expression levels via ribosome-binding site (RBS) engineering and obtained a panel of biosensors with varied sensitivities by iterative fluorescence-assisted cell sorting (FACS) in Escherichia coli to accommodate different screening purposes. To exemplify their application potential, two engineered biosensors with 10-fold different sensitivities were employed in the precise high-throughput screening by microfluidic-based fluorescence-activated droplet sorting (FADS) of Saccharopolyspora erythraea mutant libraries with different starting erythromycin productions, and mutants representing as high as 6.8 folds and over 100% of production improvements were obtained starting from the wild-type strain and the high-producing industrial strain, respectively. This work demonstrated a simple strategy to engineer biosensor performance properties, which was significant to stepwise strain engineering and production improvement.


Assuntos
Técnicas Biossensoriais , Eritromicina , Ensaios de Triagem em Larga Escala , Fatores de Transcrição/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo
16.
Langmuir ; 39(17): 5995-6005, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37086192

RESUMO

Phosphatidylinositol 4,5-bisphosphate (PIP2) is an important molecule located at the inner leaflet of cell membrane, where it serves as anchoring sites for a cohort of membrane-associated molecules and as a broad-reaching signaling intermediate. The lipid raft is thought as the major platform recruiting proteins for signal transduction and also known to mediate PIP2 accumulation across the membrane. While the significance of this cross-membrane coupling is increasingly appreciated, it remains unclear whether and how PIP2 senses the dynamic change of the ordered lipid domains over the packed hydrophobic core of the bilayer. Herein, by means of molecular dynamic simulation, we reveal that inner PIP2 molecules can sense the outer lipid domain via inter-leaflet coupling, and the coupling manner is dictated by the acyl chain length of sphingomyelin (SM) partitioned to the lipid domain. Shorter SM promotes membrane domain registration, whereby PIP2 accumulates beneath the domain across the membrane. In contrast, the anti-registration is thermodynamically preferred if the lipid domain has longer SM due to the hydrophobic mismatch between the corresponding acyl chains in SM and PIP2. In this case, PIP2 is expelled by the domain with a higher diffusivity. These results provide molecular insights into the regulatory mechanism of correlation between the outer lipid domain and inner PIP2, both of which are critical components for cell signal transduction.


Assuntos
Fosfatidilinositóis , Esfingomielinas , Humanos , Fosfatidilinositóis/análise , Fosfatidilinositóis/metabolismo , Membrana Celular/química , Simulação de Dinâmica Molecular , Microdomínios da Membrana/química , Fosfatidilinositol 4,5-Difosfato/análise , Fosfatidilinositol 4,5-Difosfato/química , Fosfatidilinositol 4,5-Difosfato/metabolismo
17.
Microorganisms ; 11(4)2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37110496

RESUMO

Bacillus subtilis is one of the commonly used industrial strains for riboflavin production. High-throughput screening is useful in biotechnology, but there are still an insufficient number of articles focusing on improving the riboflavin production of B. subtilis by this powerful tool. With droplet-based microfluidics technology, single cells can be encapsulated in droplets. The screening can be carried out by detecting the fluorescence intensity of secreted riboflavin. Thus, an efficient and high-throughput screening method suitable for riboflavin production strain improvement could be established. In this study, droplet-based microfluidics screening was applied, and a more competitive riboflavin producer U3 was selected from the random mutation library of strain S1. The riboflavin production and biomass of U3 were higher than that of S1 in flask fermentation. In addition, the results of fed-batch fermentation showed that the riboflavin production of U3 was 24.3 g/L, an 18% increase compared with the parent strain S1 (20.6 g/L), and the yield (g riboflavin/100 g glucose) increased by 19%, from 7.3 (S1) to 8.7 (U3). Two mutations of U3 (sinRG89R and icdD28E) were identified through whole genome sequencing and comparison. Then they were introduced into BS168DR (parent of S1) for further analysis, which also caused riboflavin production to increase. This paper provides protocols for screening riboflavin-producing B. subtilis with droplet-based microfluidics technology and reveals mutations in riboflavin overproduction strains.

18.
Microb Biotechnol ; 16(8): 1657-1670, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36946260

RESUMO

The characterization of bacterial strains with efficient root colonization ability and the mechanisms responsible for their efficient colonization is critical for the identification and application of beneficial bacteria. In this study, we found that Burkholderia strain B23 exhibited a strong niche differentiation between the rhizosphere and rhizoplane (a niche with more abundant easy-to-use nutrients but stronger selective pressures compared with the tightly adjacent rhizosphere) when inoculated into the field-grown citrus trees. Full-length 16S rDNA amplicon analysis demonstrated that the relative abundance of B23 in the rhizoplane microbiome at 3, 5, and 9 days post-inoculation (dpi) was always higher than that at 1 dpi, whereas its relative abundance in the rhizosphere microbiome was decreased continuously, as demonstrated by a 3.18-fold decrease at 9 dpi compared to 1 dpi. Time-series comparative expression profiling of B23 between the rhizoplane and rhizosphere was performed at representative time points (1, 3, and 9 dpi) through metatranscriptomic analysis, and the results demonstrated that multiple genes involved in the uptake and utilization of easy-to-use carbohydrates and amino acids and those involved in metabolism, energy production, replication, and translation were upregulated in the rhizoplane compared with the rhizosphere at 1 dpi and 3 dpi. Several genes involved in resistance to plant- and microbial competitor-derived stresses exhibited higher expression activities in the rhizoplane compared with the rhizosphere. Furthermore, gene loci responsible for the biosynthesis of the key antifungal and antibacterial metabolites occidiofungin and ornibactin were induced, and their expression levels remained relatively stable from 3 dpi to 9 dpi in the rhizoplane but not in the rhizosphere. Collectively, our findings provide novel lights into the mechanisms underlying the root colonization of the inoculated bacterial strains and serve as a basis for the identification of strains with efficient colonization ability, thus contributing to the development of beneficial bacteria applications.


Assuntos
Burkholderia , Citrus , Rizosfera , DNA Ribossômico , Plantas , Raízes de Plantas/microbiologia , Microbiologia do Solo
19.
Chem Commun (Camb) ; 59(28): 4237-4240, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-36942561

RESUMO

is the important electrochemical intermediate in Li-S batteries of highly solvating solvents. Herein, the dissociation of into is deeply studied. light is proven to promote the formation of from the dissociation of . Accordingly, a strategy of pre-introducing highly active into DMSO-based electrolyte is proposed to activate sulfur cathodes of Li-S batteries.

20.
Thorac Cancer ; 14(12): 1098-1101, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36924059

RESUMO

Thoracoscopic segmentectomy might be an alternative to lobectomy for small size lung cancer. Precise identification of the pulmonary intersegmental plane was needed for an optimal segmentectomy. Recently, (1) the ultra-high-definition 4K systems had claimed to overcome the lack of depth perception by secondary visual cues; (2) the no-waiting procedure was induced as an alternative and optimized method for identifying the plane. It was unclear whether combined ultra-high-definition 4K endovision systems with "no-waiting" technique in thoracoscopic segmentectomy could achieve an excellent result. A 68-year-old female patient was admitted into our hospital for occasional pulmonary nodule during her routine physical examination. The nodule is located between S8 and S9 segment, and was suspected to be an early-stage lung cancer. She underwent a thoracoscopic S89 complex segmentectomy using ultra-high-definition 4K endovision systems and "no-waiting" surgical technique. The intersegmental plane was clearly detected and easily treated by the endoscopic linear cutting staplers. The patient recovered well and was discharged without complications. Combining ultra-high-definition 4K endovision systems with "no-waiting" technique seems to be an optimal thoracoscopic segmentectomy approach for the management of lung cancers.


Assuntos
Neoplasias Pulmonares , Pneumonectomia , Feminino , Humanos , Idoso , Pneumonectomia/métodos , Neoplasias Pulmonares/cirurgia , Pulmão/cirurgia , Toracoscopia/métodos
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