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1.
J Agric Food Chem ; 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090787

RESUMO

Inulin has found commercial applications in the pharmaceutical, nutraceutical, and food industries due to its beneficial health effects. The enzymatic biosynthesis of microbial inulin has garnered increasing attention. In this study, molecular modification was applied to Lactobacillus mulieris UMB7800 inulosucrase, an enzyme that specifically produces high-molecular weight inulin, to enhance its catalytic activity and thermostability. Among the 18 variable regions, R5 was identified as a crucial region significantly impacting enzymatic activity by replacing it with more conserved sequences. Site-directed mutagenesis combined with saturated mutagenesis revealed that the mutant A250 V increased activity by 68%. Additionally, after screening candidate mutants by rational design, four single-point mutants, S344D, H434P, E526D, and G531P, were shown to enhance thermostability. The final combinational mutant, M5, exhibited a 66% increase in activity and a 5-fold enhancement in half-life at 55 °C. These findings are significant for understanding the catalytic activity and thermostability of inulosucrase and are promising for the development of microbial inulin biosynthesis platforms.

2.
J Agric Food Chem ; 72(30): 17030-17040, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39034843

RESUMO

Carbohydrate degradation is crucial for living organisms due to their essential functions in providing energy and composing various metabolic pathways. Nevertheless, in the catalytic cycle of polysaccharide degradation, the details of how the substrates bind and how the products release need more case studies. Here, we choose an inulin fructotransferase (SpIFTase) as a model system, which can degrade inulin into functionally difructose anhydride I. At first, the crystal structures of SpIFTase in the absence of carbohydrates and complex with fructosyl-nystose (GF4), difructose anhydride I, and fructose are obtained, giving the substrate trajectory and product path of SpIFTase, which are further supported by steered molecular dynamics simulations (MDSs) along with mutagenesis. Furthermore, structural topology variations at the active centers of inulin fructotransferases are suggested as the structural base for product release, subsequently proven by substitution mutagenesis and MDSs. Therefore, this study provides a case in point for a deep understanding of the catalytic cycle with substrate trajectory and product path.


Assuntos
Hexosiltransferases , Inulina , Hexosiltransferases/química , Hexosiltransferases/metabolismo , Hexosiltransferases/genética , Inulina/metabolismo , Inulina/química , Especificidade por Substrato , Simulação de Dinâmica Molecular , Domínio Catalítico , Biocatálise , Catálise , Frutose/metabolismo , Frutose/química
3.
Trends Plant Sci ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39079769

RESUMO

Regulating gene expression in plant development and environmental responses is vital for mitigating the effects of climate change on crop growth and productivity. The eukaryotic genome largely shows the canonical B-DNA structure that is organized into nucleosomes with histone modifications shaping the epigenome. Nuclear proteins and RNA interactions influence chromatin conformations and dynamically modulate gene activity. Non-B DNA conformations and their transitions introduce novel aspects to gene expression modulation, particularly in response to environmental shifts. We explore the current understanding of non-B DNA structures in plant genomes, their interplay with epigenomics and gene expression, and advances in methods for their mapping and characterization. The exploration of so far uncharacterized non-B DNA structures remains an intriguing area in plant chromatin research and offers insights into their potential role in gene regulation.

4.
Phys Chem Chem Phys ; 26(30): 20562-20575, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39036946

RESUMO

In this research, a series of K+-intercalated quasi-1D vanadium-based nano-ribbons (KxV2O5 NRs) were synthesized via a facile solvothermal method. The solvation and reductive effects of vanadium oxide precursors (V2O5 powder) on the crystallization and growth of KxV2O5 NRs were studied. Besides, post-heat treatment was performed to improve the crystallinity of KxV2O5 NRs. These KxV2O5 NRs were adopted as active cathodes for potassium-ion batteries (PIBs), whose K+ storage properties were systematically evaluated using various electrochemical methods. The relationship among the morphology, crystallinity, working voltage window and electrochemical reversible K+ storage performance of KxV2O5 NRs was studied and established. Results reveal that KxV2O5-HG, which was prepared via a solvothermal reaction involving a solvation process (using H2O2) and a proper reducing condition (proper dose of glucose) with V2O5 powder as the raw material, would be more beneficial for the reversible storage of K+ when used as the cathode for PIBs compared to other contrast samples. In addition, the enhanced crystallinity and slightly broadened working voltage window of KxV2O5-HG could hinder its long-term cycling stability upon repeated K+ insertions/extractions.

5.
J Transl Med ; 22(1): 641, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982548

RESUMO

BACKGROUND: Trastuzumab and pertuzumab combination has been approved for the treatment of patients with HER2-positive metastatic breast cancer. However, trastuzumab and pertuzumab combination did not show improvement in overall survival in patients with HER2-positive metastatic gastric cancer. METHODS: We developed a new HER2-targeted monoclonal antibody, HLX22, targeting HER2 subdomain IV as trastuzumab but with non-overlapping epitopes. We examined the antitumor effects of this novel HER2-antibody in gastric cell lines and cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models. RESULTS: HLX22 in combination with HLX02 (trastuzumab biosimilar) induced enhancement of HER2/HER2 homodimers and HER2/EGFR heterodimers internalization, which ultimately led to the reduction in signal transductions involving STAT3, P70 S6, and AKT; gene expressions of FGF-FGFR-PI3K-MTOR, EGF-EGFR-RAS, TGF-ß-SMAD, PLCG and cell cycle progression related pathways that favor tumor development, proliferation, progression, migration and survival in gastric cancer cell line NCI-N87 were also reduced. These differing but complementary actions contributed to the synergistic antitumor efficacy of the HLX22 and HLX02 combination in gastric cancer cell lines, CDX and PDX. In addition, HLX22 in combination with HLX02 demonstrated stronger antitumor efficacy than HLX02 and HLX11 (a potential pertuzumab biosimilar) combination treatment both in vitro and in vivo. CONCLUSIONS: These results suggested that the application of non-competing antibodies HLX22 and HLX02 targeting HER2 subdomain IV together may be of substantial benefit to gastric cancer patients who currently respond suboptimal to trastuzumab therapy.


Assuntos
Epitopos , Receptores ErbB , Receptor ErbB-2 , Neoplasias Gástricas , Ensaios Antitumorais Modelo de Xenoenxerto , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/metabolismo , Humanos , Receptor ErbB-2/metabolismo , Linhagem Celular Tumoral , Animais , Receptores ErbB/metabolismo , Multimerização Proteica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Domínios Proteicos , Feminino , Camundongos , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico
6.
ACS Omega ; 9(28): 30846-30858, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39035941

RESUMO

Curved nanochannels are prevalent in porous and tortuous materials, with shale matrices being a noteworthy example. The tortuosity of shale matrices significantly influences the behavior of shale gas, holding crucial implications for gas recovery engineering. In this study, we employ molecular dynamics simulation (MD) to investigate the impact of curvature and radius in tortuous nanochannel formed by a curved single-walled carbon nanotube (SWCNT) on the adsorption and transport properties of methane gas fluid. Our findings reveal that the inner half surface of the SWCNT, characterized by negative curvature, exhibits enhanced methane adsorption. Methane in straighter and narrower channels displays higher flow velocities, while wider channels exhibit higher flow flux. The nonzero flow velocity alters adsorption strength, causing the outer half to surpass the inner half. Tangent and vertical velocities of the flow are heterogeneously distributed in the channel, with the outer half having higher tangent velocities. Additionally, a vertical velocity pulse near the entrance induces turbulent vortex flow, slowing down the tangent flow velocity. This research contributes to a deeper understanding of shale gas properties in matrices with bent and curved channels, offering insights into nanofluids in carbon nanotubes and porous media featuring curved nanochannels.

7.
Zhongguo Zhong Yao Za Zhi ; 49(12): 3168-3177, 2024 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-39041077

RESUMO

Ventricular remodeling after myocardial infarction(VRAMI) is a pathological phenomenon triggered by the abrupt occlusion of coronary arteries, leading to myocardial ischemia and hypoxia. This intricate process encompasses alterations in the dimensions, composition, and elasticity of the ventricular tissue and reflects pathophysiological reactions and self-repair after cardiomyocytes are damaged. The characteristic pathological manifestation of VRAMI is the presence of myocardial fibrosis(MF), wherein fibrotic cardiac tissue undergoes a loss of contractile and relaxation capacity, ultimately culminating in heart failure(HF) and significantly impacting the patient's prognosis. Endothelial-mesenchymal transition(EndMT) is a biological process in which endothelial cells, in response to diverse pathological stimuli such as ischemia and hypoxia in the embryonic development period, undergo morphological alterations and functional impairment, progressively acquiring mesenchymal cell properties and ultimately differentiating into mesenchymal cells. The ongoing advancement of the EndMT process will result in an excessive buildup of collagen, thereby inducing structural harm to the myocardium and exacerbating the processes of VRAMI and MF. Recent investigations have demonstrated the pivotal involvement of EndMT in the pathological advancement of VRAMI. Consequently, a targeted intervention aimed at effectively impeding VRAMI, safeguarding cardiac function, and potentially serving as a novel therapeutic target for the prevention and treatment of VRAMI. This article provides a comprehensive review of recent Chinese and international literature, focusing on the role and pathophysiological mechanisms of EndMT in VRAMI. Additionally, it discusses the research progress of innovative targeted interventions using both traditional Chinese and Western medicine, so as to offer new insights and a theoretical foundation for the clinical treatment of the disease.


Assuntos
Infarto do Miocárdio , Remodelação Ventricular , Humanos , Infarto do Miocárdio/fisiopatologia , Animais , Medicamentos de Ervas Chinesas , Células Endoteliais , Transição Epitelial-Mesenquimal , Medicina Tradicional Chinesa , Transição Endotélio-Mesênquima
8.
Chem Asian J ; : e202400716, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39041455

RESUMO

Excessive sulfur dioxide (SO2) disturbs physiology of lysosomes causing diseases and threatening human health. A fluorescent probe has been regarded as one of the most attractive approaches, which is compatible with living cells and possesses high sensitivity. However, most of fluorescent probes' reaction sites are activated before they reach the destination. In this work, an acid-activatable fluorescent probe PT1 was synthesized, characterized, and used for SO2 detection. The introduction of oxazolines in PT1 enables the intelligent response of probe to release the activation stie for SO2 derivatives through Michael addition upon exposure to acid. In vitro studies showed a remarkable selectivity of PT1 to SO2 derivatives than other biothiols with a limit of detection as low as 62 nM. Precise spatiotemporal identification of lysosomal SO2 fluctuations has been successfully performed by PT1. Furthermore, PT1 can be applied for monitoring SO2 derivatives in traditional Chinese medicines.

9.
Environ Sci Technol ; 58(29): 12875-12887, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38980177

RESUMO

There has been widespread concern about the health hazards of per- and polyfluoroalkyl substances (PFAS), which may be the risk factor for hyperuricemia with evidence still insufficient in the general population in China. Here, we conducted a nationwide study involving 9,580 adults aged 18 years or older from 2017 to 2018, measured serum concentrations of uric acid and PFAS (PFOA, PFOS, 6:2 Cl-PFESA, PFNA, PFHxS) in participants, to assess the associations of individual PFAS with hyperuricemia, and estimated a joint effect of PFAS mixtures. We found positive associations of higher serum PFAS with elevated odds of hyperuricemia in Chinese adults, with the greatest contribution from PFOA (69.37%). The nonmonotonic dose-response (NMDR) relationships were observed for 6:2 Cl-PFESA and PFHxS with hyperuricemia. Participants with less marine fish consumption, overweight, and obesity may be the sensitive groups to the effects of PFAS on hyperuricemia. We highlight the potential health hazards of legacy long-chain PFAS (PFOA) once again because of the higher weights of joint effects. This study also provides more evidence about the NMDR relationships in PFAS with hyperuricemia and emphasizes a theoretical basis for public health planning to reduce the health hazards of PFAS in sensitive groups.


Assuntos
Hiperuricemia , Hiperuricemia/epidemiologia , Hiperuricemia/sangue , Humanos , Estudos Transversais , Adulto , Masculino , Feminino , Fluorocarbonos/sangue , Pessoa de Meia-Idade , China/epidemiologia , Ácido Úrico/sangue
10.
Chin J Cancer Res ; 36(3): 298-305, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38988482

RESUMO

Objective: Nucleotide excision repair (NER) plays a vital role in maintaining genome stability, and the effect of NER gene polymorphisms on hepatoblastoma susceptibility is still under investigation. This study aimed to evaluate the relationship between NER gene polymorphisms and the risk of hepatoblastoma in Eastern Chinese Han children. Methods: In this five-center case-control study, we enrolled 966 subjects from East China (193 hepatoblastoma patients and 773 healthy controls). The TaqMan method was used to genotype 19 single nucleotide polymorphisms (SNPs) in NER pathway genes, including ERCC1, XPA, XPC, XPD, XPF, and XPG. Then, multivariate logistic regression analysis was performed, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were utilized to assess the strength of associations. Results: Three SNPs were related to hepatoblastoma risk. XPC rs2229090 and XPD rs3810366 significantly contributed to hepatoblastoma risk according to the dominant model (adjusted OR=1.49, 95% CI=1.07-2.08, P=0.019; adjusted OR=1.66, 95% CI=1.12-2.45, P=0.012, respectively). However, XPD rs238406 conferred a significantly decreased risk of hepatoblastoma under the dominant model (adjusted OR=0.68, 95% CI=0.49-0.95; P=0.024). Stratified analysis demonstrated that these significant associations were more prominent in certain subgroups. Moreover, there was evidence of functional implications of these significant SNPs suggested by online expression quantitative trait loci (eQTLs) and splicing quantitative trait loci (sQTLs) analysis. Conclusions: In summary, NER pathway gene polymorphisms (XPC rs2229090, XPD rs3810366, and XPD rs238406) are significantly associated with hepatoblastoma risk, and further research is required to verify these findings.

12.
Phys Med Biol ; 69(14)2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38959904

RESUMO

Functional nanomaterials have emerged as versatile nanotransducers for wireless neural modulation because of their minimal invasion and high spatiotemporal resolution. The nanotransducers can convert external excitation sources (e.g. NIR light, x-rays, and magnetic fields) to visible light (or local heat) to activate optogenetic opsins and thermosensitive ion channels for neuromodulation. The present review provides insights into the fundamentals of the mostly used functional nanomaterials in wireless neuromodulation including upconversion nanoparticles, nanoscintillators, and magnetic nanoparticles. We further discussed the recent developments in design strategies of functional nanomaterials with enhanced energy conversion performance that have greatly expanded the field of neuromodulation. We summarized the applications of functional nanomaterials-mediated wireless neuromodulation techniques, including exciting/silencing neurons, modulating brain activity, controlling motor behaviors, and regulating peripheral organ function in mice. Finally, we discussed some key considerations in functional nanotransducer-mediated wireless neuromodulation along with the current challenges and future directions.


Assuntos
Tecnologia sem Fio , Animais , Humanos , Optogenética/métodos , Neurônios , Nanoestruturas , Nanotecnologia/métodos , Nanotecnologia/instrumentação
13.
Indian J Ophthalmol ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990612

RESUMO

PURPOSE: To quantitatively investigate the reflectivity and structure of the outer retinal layers in children with hyperopic anisometropic amblyopia by using swept-source optical coherence tomography (SS-OCT). METHODS: Seventy-eight patients with amblyopia and 64 age-matched children with normal vision were included in this study. All participants underwent SS-OCT and detailed ophthalmic examinations. Longitudinal reflectance profile measurements were measured using Image J. The reflectivity of outer retinal layers was measured at the three selected positions: subfovea, 1 mm nasal to the fovea, and 1 mm temporal to the fovea. The reflectivity ratios were calculated by outer retinal layers divided by the nuclear layer (ONL) for normalization. Photoreceptor outer segment layer thickness was also measured. The results were compared between the amblyopia and normal controls. The possible effects of age, sex, and axial length on results were adjusted by generalized estimating equations. RESULTS: Photoreceptor outer segment layer thickness was significantly greater in amblyopic eyes than in normal control eyes at all three regions (18.41 ± 1.83 vs. 16.84 ± 1.39, P < 0.001 at the fovea; 14.78 ± 1.34 vs. 14.19 ± 1.40, P = 0.030 at 1 mm nasal to the foveal; 14.92 ± 1.48 vs. 14.41 ± 1.32, P = 0.049 at 1 mm temporal to the fovea). The reflectivity ratio of outer segment/ONL was higher only at 1 mm nasal to the fovea (2.94 ± 0.61 vs. 2.70 ± 0.42, P = 0.02). Subfoveal OS thickness was positively correlated with choroidal thickness (r = 0.248, P = 0.018) but was not correlated with spherical equivalent, age, axial length, or logMAR visual acuity. CONCLUSION: Quantitative measurement of SS-OCT images revealed greater photoreceptor outer segments in both eyes of children with amblyopia than in normal control eyes. A thicker OS thickness is somehow related to amblyopia, and this may be a new useful diagnostic parameter for amblyopia.

14.
Small ; : e2402915, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38845481

RESUMO

The bismuth anode has garnered significant attention due to its high theoretical Na-storage capacity (386 mAh g-1). There have been numerous research reports on the stable solid electrolyte interphase (SEI) facilitated by electrolytes utilizing ether solvents. In this contribution, cyclic tetrahydrofuran (THF) and 2-methyltetrahydrofuran (MeTHF) ethers are employed as solvents to investigate the sodium-ion storage properties of bismuth anodes. A series of detailed characterizations are utilized to analyze the impact of electrolyte solvation structure and SEI chemical composition on the kinetics of sodium-ion storage. The findings reveal that bismuth anodes in both THF and MeTHF-based electrolytes exhibit exceptional rate performance at low current densities, but in THF-based electrolytes, the reversible capacity is higher at high current densities (316.7 mAh g-1 in THF compared to 9.7 mAh g-1 in MeTHF at 50 A g-1). This stark difference is attributed to the formation of an inorganic-rich, thin, and uniform SEI derived from THF-based electrolyte. Although the SEI derived from MeTHF-based electrolyte also consists predominantly of inorganic components, it is thicker and contains more organic species compared to the THF-derived SEI, impeding charge transfer and ion diffusion. This study offers valuable insights into the utilization of cyclic ether electrolytes for Na-ion batteries.

15.
Artigo em Inglês | MEDLINE | ID: mdl-38889027

RESUMO

The ICU is a specialized hospital department that offers critical care to patients at high risk. The massive burden of ICU-requiring care requires accurate and timely ICU outcome predictions for alleviating the economic and healthcare burdens imposed by critical care needs. Existing research faces challenges such as feature extraction difficulties, low accuracy, and resource-intensive features. Some studies have explored deep learning models that utilize raw clinical inputs. However, these models are considered non-interpretable black boxes, which prevents their wide application. The objective of the study is to develop a new method using stochastic signal analysis and machine learning techniques to effectively extract features with strong predictive power from ICU patients' real-time time series of vital signs for accurate and timely ICU outcome prediction. The results show the proposed method extracted meaningful features and outperforms baseline methods, including APACHE IV (AUC = 0.750), deep learning-based models (AUC = 0.732, 0.712, 0.698, 0.722), and statistical feature classification methods (AUC = 0.765) by a large margin (AUC = 0.869). The proposed method has clinical, management, and administrative implications since it enables healthcare professionals to identify deviations from prognostications timely and accurately and, therefore, to conduct proper interventions.

16.
Int J Nanomedicine ; 19: 5173-5191, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38855733

RESUMO

Purpose: Acne vulgaris is a chronic inflammatory skin disorder centered on hair follicles, making hair follicle-targeted delivery of anti-acne drugs a promising option for acne treatment. However, current researches have only focused on the delivering to healthy hair follicles, which are intrinsically different from pathologically clogged hair follicles in acne vulgaris. Patients and Methods: Azelaic acid (AZA) micro/nanocrystals with different particle sizes were prepared by wet media milling or high-pressure homogenization. An experiment on AZA micro/nanocrystals delivering to healthy hair follicles was carried out, with and without the use of physical enhancement techniques. More importantly, it innovatively designed an experiment, which could reveal the ability of AZA micro/nanocrystals to penetrate the constructed clogged hair follicles. The anti-inflammatory and antibacterial effects of AZA micro/nanocrystals were evaluated in vitro using a RAW264.7 cell model stimulated by lipopolysaccharide and a Cutibacterium acnes model. Finally, both the anti-acne effects and skin safety of AZA micro/nanocrystals and commercial products were compared in vivo. Results: In comparison to commercial products, 200 nm and 500 nm AZA micro/nanocrystals exhibited an increased capacity to target hair follicles. In the combination group of AZA micro/nanocrystals and ultrasound, the ability to penetrate hair follicles was further remarkably enhanced (ER value up to 9.6). However, toward the clogged hair follicles, AZA micro/nanocrystals cannot easily penetrate into by themselves. Only with the help of 1% salicylic acid, AZA micro/nanocrystals had a great potential to penetrate clogged hair follicle. It was also shown that AZA micro/nanocrystals had anti-inflammatory and antibacterial effects by inhibiting pro-inflammatory factors and Cutibacterium acnes. Compared with commercial products, the combination of AZA micro/nanocrystals and ultrasound exhibited an obvious advantage in both skin safety and in vivo anti-acne therapeutic efficacy. Conclusion: Hair follicle-targeted delivery of AZA micro/nanocrystals provided a satisfactory alternative in promoting the treatment of acne vulgaris.


Assuntos
Acne Vulgar , Antibacterianos , Ácidos Dicarboxílicos , Folículo Piloso , Nanopartículas , Acne Vulgar/tratamento farmacológico , Animais , Camundongos , Ácidos Dicarboxílicos/química , Ácidos Dicarboxílicos/farmacologia , Folículo Piloso/efeitos dos fármacos , Células RAW 264.7 , Nanopartículas/química , Antibacterianos/farmacologia , Antibacterianos/química , Humanos , Tamanho da Partícula , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Pele/efeitos dos fármacos , Pele/metabolismo
17.
Plant Physiol ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38917225

RESUMO

Single-stranded DNA (ssDNA) is essential for various DNA-templated processes in both eukaryotes and prokaryotes. However, comprehensive characterizations of ssDNA still lag in plants compared to non-plant systems. Here, we conducted in situ S1-seq (ISS1-seq), with starting gDNA ranging from 5 µg to 250 ng, followed by comprehensive characterizations of ssDNA in rice (Oryza sativa L.). We found that ssDNA loci were substantially associated with a subset of non-B DNA structures and functional genomic loci. Subtypes of ssDNA loci had distinct epigenetic features. Importantly, ssDNA may act alone or partly coordinate with non-B DNA structures, functional genomic loci, or epigenetic marks to actively or repressively modulate gene transcription, which is genomic-region-dependent and associated with the distinct accumulation of RNA Pol II. Moreover, distinct types of ssDNA had differential impacts on the activities and evolution of TEs (especially common or conserved TEs) in the rice genome. Our study showcases an antibody-independent technique for characterizing non-B DNA structures or functional genomic loci in plants. It lays the groundwork and fills a crucial gap for further exploration of ssDNA, non-B DNA structures, or functional genomic loci, thereby advancing our understanding of their biology in plants.

18.
Enzyme Microb Technol ; 179: 110465, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38852283

RESUMO

Enzymatic production of D-mannose attracts increasing attention because of the health effects and commercial values of D-mannose. Several kinds of epimerases or isomerases have been used for enzymatic production of D-mannose from D-glucose or D-fructose. D-Mannose epimerase (MEase), belonging to N-acyl-D-glucosamine 2-epimerase superfamily enzymes, catalyzes the C-2 epimerization between D-glucose and D-mannose. In this study, a novel MEase was identified from Cytophagaceae bacterium SJW1-29. Sequence and structure alignments indicate that it is highly conserved with the reported R. slithyformis MEase with the known crystal structure. It was a metal-independent enzyme, with an optimal pH of 8.0 and an optimal temperature of 40 °C. The specific activities on D-glucose and D-mannose were 2.90 and 2.96 U/mg, respectively. The Km, kcat, and kcat/Km on D-glucose were measured to be 194.9 mM, 2.72 s-1, and 0.014 mM-1 s-1, respectively. The purified enzyme produced 23.15 g/L of D-mannose from 100 g/L of D-glucose at pH 8.0 and 40 °C for 8 h, with a conversion rate of 23.15 %.


Assuntos
Carboidratos Epimerases , Glucose , Manose , Manose/metabolismo , Glucose/metabolismo , Especificidade por Substrato , Cinética , Carboidratos Epimerases/metabolismo , Carboidratos Epimerases/genética , Carboidratos Epimerases/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Concentração de Íons de Hidrogênio , Sequência de Aminoácidos , Clonagem Molecular , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Temperatura , Modelos Moleculares , Alinhamento de Sequência
19.
J Colloid Interface Sci ; 672: 401-414, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38850865

RESUMO

Crafting an inorganic semiconductor heterojunction with defect engineering and morphology modulation is a strategic approach to produce clean energy by the highly efficient light-driven splitting of water. In this paper, a novel Z-scheme sulfur-vacancy containing Zn3In2S6 (Vs-Zn3In2S6) nanosheets/In2O3 hollow hexagonal prisms heterostructrue (Vs-ZIS6INO) was firstly constructed by an oil bath method, in which Vs-Zn3In2S6 nanosheets grew on the surfaces of In2O3 hollow hexagonal prisms to form a hollow core-shell structure. The obtained Vs-ZIS6INO heterostructrue exhibited much enhanced activity of the production of H2 and H2O2 by the light-driven water splitting. In particular, under visible light irradiation (λ > 420 nm), the rate of generation of H2 of Vs-ZIS6INO sample containing 30 wt% Vs-Zn3In2S6 (30Vs-ZIS6INO) could reach 3721 µmol g-1h-1, which was 87 and 6 times higher than those of Zn3In2S6 (43 µmol g-1h-1) and Vs-Zn3In2S6 (586 µmol g-1h-1), respectively. Meanwhile, 30Vs-ZIS6INO could exhibit the rate of H2O2 production of 483 µmol g-1h-1 through the dual pathways of indirect 2e- oxygen reduction (ORR) and water oxidation (WOR) without adding any sacrifice agents, far exceeding In2O3 (7 µmol g-1h-1) and Vs-Zn3In2S6 (58 µmol g-1h-1). The excellent photocatalytic activities of H2 and H2O2 generations of Vs-ZIS6INO sample might result from the synergistic effect of the sulfur vacancy, hollow core-shell structure, and Z-scheme heterostructure, which accelerated the electron delocalization, enhanced the absorption and conversion of solar energy, reduced the carrier diffusion distance, and ensured high REDOX ability. In addition, the possible photocatalytic mechanisms for the production of H2 and H2O2 were discussed in detail. This study provided a new idea and reference for constructing the novel and efficient inorganic semiconductor heterostructures by coordinating vacancy defect and morphology design to adequately utilize water splitting for the production of clean energy.

20.
J Control Release ; 372: 69-84, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38866244

RESUMO

Transcytosis-inducing nanomedicines have been developed to improve tumor extravasation. However, the fate during transcytosis across multicell layers and the structural integrity of the nanomedicines before reaching tumor cells could impact antitumor therapy. Here, a BAY 87-2243 (a hypoxia-inducible factor-1 inhibitor)-loaded liposomal system (HA-P-LBAY) modified by low molecular weight protamine (LMWP) and crosslinked by hyaluronic acid (HA) was constructed. This system could accomplish differentiate cellular transport in endothelial and tumor cells by fine-tuning its structural integrity, i.e. transcytosis across the endothelial cells while preserving structural integrity, facilitating subsequent retention and drug release within tumor cells via degradation-induced aggregation. In vitro cellular uptake and transwell studies demonstrated that HA-P-LBAY were internalized by endothelial cells (bEnd.3) via an active, caveolin and heparin sulfate proteoglycan (HSPG)-mediated endocytosis, and subsequently achieved transcytosis mainly through the ER/Golgi pathway. Moreover, the fluorescence resonance energy transfer (FRET) study showed that HA-crosslinking maintained higher integrity of HA-P-LBAY after transcytosis, more efficiently than electrostatic coating of HA (HA/P-LBAY). In addition, more HA-P-LBAY was retained in tumor cells (4T1) compared to HA/P-LBAY corresponding to its enhanced in vitro cytotoxicity. This may be attributed to better integrity of HA-P-LBAY post endothelial transcytosis and more degradation of HA in tumor cells, leading to more liposome aggregation and inhibition of their transcytosis, which was inferred by both TEM images and the HAase responsiveness assay proved by FRET. In vivo, HA-P-LBAY exhibited more potency in tumor suppression than the other formulations in both low and high permeability tumor models. This highlighted that fine-tuning of structural integrity of nanocarriers played a key role no matter whether the transcytosis of nanocarriers contributed to cellular transport. Collectively, this study provides a promising strategy for antitumor therapies by fine-tuning liposome integrity to achieve active trans-endothelial transport with structural integrity and selective aggregation for prolonged tumor retention.


Assuntos
Antineoplásicos , Ácido Hialurônico , Lipossomos , Protaminas , Transcitose , Animais , Ácido Hialurônico/química , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Protaminas/química , Humanos , Linhagem Celular Tumoral , Feminino , Camundongos Endogâmicos BALB C , Células Endoteliais/metabolismo , Células Endoteliais/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Camundongos , Liberação Controlada de Fármacos
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