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1.
J Nutr Health Aging ; 28(6): 100223, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38598978

RESUMO

OBJECTIVES: Previous studies suggested protective associations of vegetables and fruits (VF) intake with cognitive function, but evidence on specific types of VF was insufficient. METHODS: The current study included 4066 participants from 1997 to 2006 in the China Health and Nutrition Survey (CHNS) and 6170 participants from 2013 to 2020 in the Health and Retirement Study (HRS). Dietary intake (using 3-day 24-h dietary recalls in CHNS and food frequency questionnaire in HRS) and cognitive function (using the Telephone Interview for Cognitive Status-Modified, TICS-m) were measured. Linear mixed-effects models were used to estimate the beta coefficients (ß) and the 95% confidence intervals (CI) to evaluate the association of VF with cognitive function (z-score) and its decline. RESULTS: Highest intake of total VF was associated with better cognitive function and slower cognitive decline. Differences in cognitive function z-score between the highest and lowest tertiles of VF consumption were 0.039 (95% CI: 0.002, 0.076) for CHNS and 0.063 (95% CI: 0.026, 0.100) for HRS. The corresponding differences in annual cognitive decline were 0.011 (95% CI: 0.002, 0.021) and 0.012 (95% CI: 0.003, 0.020) units respectively. Vegetables and fruits showed independent associations with cognitive function and its decline. In specific VF subgroups, when comparing the highest to the lowest tertile intake, cruciferous vegetables (ß = 0.058, 95% CI: 0.017, 0.100 in CHNS and ß = 0.067, 95% CI: 0.032, 0.101 in HRS) and green leafy vegetables (ß = 0.036, 95% CI: -0.001, 0.073 in CHNS and ß = 0.082, 95% CI: 0.046, 0.117 in HRS) was associated with better cognitive function in both cohorts. Similarly, higher intake of dark-colored vegetables (ß = 0.019, 95% CI: 0.008, 0.030 for red/yellow vegetables in CHNS and ß = 0.004, 95% CI: 0.001, 0.007 for green leafy vegetables in HRS) were associated with slower cognitive decline in subsequent years. Moreover, rigorous sensitivity analyses confirmed the stability of the results. CONCLUSIONS: Our findings support the potential beneficial roles of VF, especially cruciferous vegetables, green leafy vegetables, and red/yellow vegetables, in maintaining cognitive function and slowing cognitive decline in middle-aged and older adults.

2.
Biochem Biophys Rep ; 38: 101694, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38586826

RESUMO

Crotonylation is an importantly conserved post-translational modification, which is completely different from acetylation. In recent years, it has been confirmed that crotonylation occurs on histone and non-histone. Crotonylated Histone primarily affects gene expression through transcriptional regulation, while non-histone Crotonylation mainly regulates protein functions including protein activity, localization, and stability, as well as protein-protein interactions. The change in protein expression and function will affect the physiological process of cells and even cause disease. Reviewing previous studies, this article summarizes the mechanisms of histone and non-histone crotonylation in regulating diseases and cellular physiological processes to explore the possibility of precise regulation of crotonylation sites as potential targets for disease treatment.

3.
Front Mol Biosci ; 11: 1329580, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38516188

RESUMO

Preimplantation genetic testing for monogenic diseases (PGT-M) can be used to select embryos that do not develop disease phenotypes or carry disease-causing genes for implantation into the mother's uterus, to block disease transmission to the offspring, and to increase the birth rate of healthy newborns. However, the traditional PGT-M technique has some limitations, such as its time consumption, experimental procedural complexity, and the need for a complete family or reference embryo to construct the haplotype. In this study, proband-independent haplotyping based on NGS-based long-read sequencing (Phbol-seq) was used to effectively construct haplotypes. By targeting the mutation sites of single gene disease point mutations and small fragment deletion carriers, embryos carrying parental disease-causing mutations were successfully identified by linkage analysis. The efficiency of embryo resolution was then verified by classical Sanger sequencing, and it was confirmed that the construction of haplotype and SNP linkage analysis by Phbol-seq could accurately and effectively detect whether embryos carried parental pathogenic mutations. After the embryos confirmed to be nonpathogenic by Phbol-seq-based PGT-M and confirmed to have normal copy number variation by Phbol-seq-based PGT-A were transplanted into the uterus, gene detection in amniotic fluid of the implanted embryos was performed, and the results confirmed that Phbol-seq technology could accurately distinguish normal genotype embryos from genetically modified carrier embryos. Our results suggest that Phbol-seq is an effective strategy for accurately locating mutation sites and accurately distinguishing between embryos that inherit disease-causing genes and normal embryos that do not. This is critical for Phbol-seq-based PGT-M and could help more single-gene disease carriers with incomplete families, de novo mutations or suspected germline mosaicism to have healthy babies with normal phenotypes. It also helps to reduce the transmission of monogenic genetic diseases in the population.

4.
J Am Chem Soc ; 146(14): 9631-9639, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38530981

RESUMO

The induced structural transformation provides an efficient way to precisely modulate the fine structures and the corresponding performance of gold nanoclusters, thus constituting one of the important research topics in cluster chemistry. However, the driving forces and mechanisms of these processes are still ambiguous in many cases, limiting further applications. In this work, based on the unique coordination mode of the pincer ligand-stabilized gold nanocluster Au8(PNP)4, we revealed the site-recognition mechanism for induced transformations of gold nanoclusters. The "open nitrogen sites" on the surface of the nanocluster interact with different inducers including organic compounds and metals and trigger the conversion of Au8(PNP)4 to Au13 and Au9Ag4 nanoclusters, respectively. Control experiments verified the site-recognition mechanism, and the femtosecond and nanosecond transient absorption spectroscopy revealed the electronic and photoluminescent evolution accompanied by the structural transformation.

5.
Mol Med ; 30(1): 31, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38395742

RESUMO

BACKGROUND: Reperfusion is the most effective strategy for myocardial infarct, but induces additional injury. WD repeat and SOCS box containing protein 1 (WSB1) plays a protective role in ischemic cells. This study aims to investigate the effects of WSB1 on myocardial ischemia-reperfusion (IR) injury. METHODS: The myocardial IR was induced by left anterior descending (LAD) ligation for 45 min and subsequent reperfusion. The overexpression of WSB1 was mediated by tail vein injection of AAV9 loaded with WSB1 encoding sequence two weeks before IR surgery. H9c2 myocardial cells underwent oxygen-sugar deprivation/reperfusion (OGD/R) to mimic IR, and transfected with WSB1 overexpression or silencing plasmid to alter the expression of WSB1. RESULTS: WSB1 was found highly expressed in penumbra of myocardial IR rats, and the WSB1 overexpression relieved IR-induced cardio dysfunction, myocardial infarct and pathological damage, and cardiomyocyte death in penumbra. The ectopic expression of WSB1 in H9c2 myocardial cells mitigated OGD/R-caused apoptosis, and silencing of WSB1 exacerbated the apoptosis. In addition, WSB1 activated ß-catenin signaling, which was deactivated under the ischemic condition. The co-immunoprecipitation results revealed that WSB1 mediated ubiquitination and degradation of glycogen synthase kinase 3 beta (GSK3ß) as an E3 ligase in myocardial cells. The effects of WSB1 on myocardial cells under ischemic conditions were abolished by an inhibitor of ß-catenin signaling. CONCLUSION: WSB1 activated ß-catenin pathway by promoting the ubiquitination of GSK3ß, and restrained IR-induced myocardial injury. These findings might provide novel insights for clinical treatment of myocardial ischemic patients.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Animais , Humanos , Ratos , Apoptose , beta Catenina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Ubiquitina-Proteína Ligases , Ubiquitinação
6.
Ultrason Sonochem ; 103: 106788, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38309048

RESUMO

In this study, ultrasound (US) was evaluated for As, Cd, Pb, Mn, Sr and V extraction from seaweed samples. The following parameters of ultrasound-assisted extraction (UAE) using an US bath were: frequency (25 to 130 kHz), amplitude (30 to 100%), temperature (30 to 80 °C), sample mass (50 to 200 mg), extractant concentration (1 to 3 mol L-1 of HNO3) and treatment time (5 to 30 min). Acoustic density and power density distribution were calculated using the calorimetric method and mapping of the acoustic pressure distribution was also evaluated. The optimized UAE conditions were 200 mg of sample in 10 mL of 2 mol L-1 HNO3 and 30 min of sonication in a 25 kHz US bath (37.2 ± 4.0 W L-1) at 70% of amplitude and 70 °C. Analytes were quantified using inductively coupled plasma mass spectrometry and results were compared with values obtained using "silent" conditions (magnetic or mechanical stirring at 500 rpm, and without stirring), and a reference method based on microwave-assisted wet digestion (MAWD). The UAE method demonstrated the best extraction efficiency (higher than 95%) for all analytes, especially for As, Cd and V, with lower standard deviations (up to 5%) and lower blank values in comparison with the silent conditions. The proposed UAE method was more advantageous than the reference method, being faster, simpler, safer, more environmentally friendly, and with higher detectability (lower limits of quantification, from 0.0033 to 1.34 µg g-1). In addition, negligible blank values were obtained for UAE and no interference were observed in the determination step. Furthermore, the optimized UAE method was applied for Antarctic seaweed samples and comparison with results obtained by MAWD was satisfactory. In this sense, UAE is demonstrated to be a suitable option for sample preparation of seaweed samples and further determination of environmentally critical elements avoiding the use of concentrated reagents as in the MAWD reference method.


Assuntos
Alga Marinha , Espectrometria de Massas/métodos , Cádmio , Análise Espectral/métodos , Verduras
7.
Front Mol Neurosci ; 17: 1334862, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38318533

RESUMO

Aging-related memory impairment and pathological memory disorders such as Alzheimer's disease differ between males and females, and yet little is known about how aging-related changes in the transcriptome and chromatin environment differ between sexes in the hippocampus. To investigate this question, we compared the chromatin accessibility landscape and gene expression/alternative splicing pattern of young adult and aged mouse hippocampus in both males and females using ATAC-seq and RNA-seq. We detected significant aging-dependent changes in the expression of genes involved in immune response and synaptic function and aging-dependent changes in the alternative splicing of myelin sheath genes. We found significant sex-bias in the expression and alternative splicing of hundreds of genes, including aging-dependent female-biased expression of myelin sheath genes and aging-dependent male-biased expression of genes involved in synaptic function. Aging was associated with increased chromatin accessibility in both male and female hippocampus, especially in repetitive elements, and with an increase in LINE-1 transcription. We detected significant sex-bias in chromatin accessibility in both autosomes and the X chromosome, with male-biased accessibility enriched at promoters and CpG-rich regions. Sex differences in gene expression and chromatin accessibility were amplified with aging, findings that may shed light on sex differences in aging-related and pathological memory loss.

8.
Artigo em Inglês | MEDLINE | ID: mdl-38393838

RESUMO

In recent years, data-driven soft sensor modeling methods have been widely used in industrial production, chemistry, and biochemical. In industrial processes, the sampling rates of quality variables are always lower than those of process variables. Meanwhile, the sampling rates among quality variables are also different. However, few multi-input multi-output (MIMO) sensors take this temporal factor into consideration. To solve this problem, a deep-learning (DL) model based on a multitemporal channels convolutional neural network (MC-CNN) is proposed. In the MC-CNN, the network consists of two parts: the shared network used to extract the temporal feature and the parallel prediction network used to predict each quality variable. The modified BP algorithm makes the blank values generated at unsampled moments not participate in the backpropagation (BP) process during training. By predicting multiple quality variables of two industrial cases, the effectiveness of the proposed method is verified.

9.
Water Environ Res ; 96(2): e11004, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38369667

RESUMO

Microbial communities living in different environments can affect the transformation of nitrogen and phosphorus in sewage pipes. Two different environments were simulated to investigate the differences in the transformation of nitrogen and phosphorus under different microbial communities in the pipe. Results showed that the concentration of nitrogen and phosphorus changed greatly in the first 25-33 days and the first 21 days, respectively, and then remained stable. The decrease in amino acid nitrogen (AAN) concentration and the increase in ammonia nitrogen (NH4 + -N) concentration in the sediments were evident in the contrast group. The concentrations of total phosphorus (TP), dissolved total phosphorus (DTP), and dissolved reactive phosphorus (DRP) in the overlying water and interstitial water decreased, and that of TP in the sediment increased. Some microorganisms in the sediments of both groups are related to the transformation of nitrogen and phosphorus, such as Clostridium_sensu_stricto_1, Sporacetigenium, Norank_f__Anaerolineaceae, Norank_f__norank_o__PeM15, and Caldisericum. The relative abundance of these microorganisms was remarkably differed between the two groups, which partly caused the difference in nitrogen and phosphorus transformation among overlying water, interstitial water, and sediment in the two environments. PRACTITIONER POINTS: The concentration of N and P changed greatly in the first 20-30 days. AAN and NH4 + -N in sediments had greater concentration variation in contrast group. In two groups, TP, DTP, and DRP of water decreased, and TP of sediment increased. Microbe related to the transformation of N and P differed between the two groups.


Assuntos
Microbiota , Poluentes Químicos da Água , Esgotos , Fósforo/análise , Nitrogênio/análise , Sedimentos Geológicos/química , Poluentes Químicos da Água/química , Água , China
10.
ACS Appl Mater Interfaces ; 16(3): 3406-3415, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38215450

RESUMO

The introduction of two-dimensional materials with high capacitance that are dielectric into the triboelectric interface is critical for the development of a highly efficient triboelectric nanogenerator (TENG) due to its excellent electrical conductivity and versatile surface chemistry. This paper reports a spring-structured multilayer TENG (S-TENG), where a Nb2CTx MXene-PVDF composite was chosen as the triboelectric electrode for increasing the dielectric and surface charge density. The intense electrostatic interaction of the strong hydrogen bonds between anions on the MXene surface and hydrogen atoms of PVDF chains not only creates a dipole in responding to the applied electric field but also promotes the formation of a piezoelectric phase and induces a strong interface coupling effect. Consequently, an output power enhancement of 300% was shown in comparison with pure PVDF, and a spring-like design with a multilayer structure further increases the space utilization and contact area and presents an output voltage of 420 V, a current density of 1.47 mA/m2, and a maximal output power density of 619 mW/m2. In addition, the as-prepared S-TENG can serve as both a fluid energy harvester on an urban river and a real-time monitor to realize the automatic alarm of water level warning.

11.
Water Environ Res ; 96(1): e10976, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38225832

RESUMO

In this work, the transformation law of nitrogen in sediment-water system under different flow rates and wastewater concentrations were investigated in a simulated sewage pipeline system. Results showed that the different flow rates and wastewater concentrations in the pipeline caused differences in microbial community in sediments and nitrogen transformation. When the flow rate increased from 0.05 to 0.2 m/s, the scouring effect was enhanced, resulting in higher concentrations of NH4 + -N and NO3 - -N in the overlying water. At 0.2 m/s, the relative abundance of Clostridium_sensu_stricto_1 in sediments was higher, resulting in a greater conversion of amino acid nitrogen (AAN) to NH4 + -N. Meanwhile, many denitrifying bacteria (Trichococcus, Dechloromonas, norank_f__norank_o__Gaiellales, Thiobacillus) had high relative abundance in the sediments, and the denitrification process was common. When the wastewater concentration was high, the nitrification reaction was great in overlying and interstitial water. Moreover, the ammoniation process was great in the sediments, and the variation flux of AAN was large (remarkably reduced). PRACTITIONER POINTS: AAN transformed to NH4 + -N in sediment under different flow rate and concentration. Scouring was enhanced at 0.2 m/s, increasing nitrogen contents in overlying water. Difference in microbial community led to more AAN conversion to NH4 + -N at 0.2 m/s. The ammoniation process was greater in sediment at a high concentration of sewage. NH4 + -N migrated from overlying water to sediment at a high concentration of sewage.


Assuntos
Esgotos , Águas Residuárias , Desnitrificação , Água , Nitrogênio/análise , Nitrificação , Bactérias
12.
Small ; 20(2): e2304311, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37697695

RESUMO

Due to the increased integration and miniaturization of electronic devices, traditional electronic packaging materials, such as epoxy resin (EP), cannot solve electromagnetic interference (EMI) in electronic devices. Thus, the development of multifunctional electronic packaging materials with superior electromagnetic wave absorption (EMA), high heat dissipation, and flame retardancy is critical for current demand. This study employs an in-situ growth method to load layered double hydroxides (LDH) onto transition metal carbides (MXene), synthesizing a novel composite material (MXene@LDH). MXene@LDH possesses a sandwich structure and exhibits excellent EMA performance, thermal conductivity, and flame retardancy. By adjusting the load of LDH, under the synergistic effect of multiple factors, such as dielectric and polarization losses, this work achieves an EMA material with a remarkable minimum reflection loss (RL) of -52.064 dB and a maximum effective absorption bandwidth (EAB) of 4.5 GHz. Furthermore, MXene@LDH emerges a bridging effect in EP, namely MXene@LDH/EP, leading to a 118.75% increase in thermal conductivity compared to EP. Simultaneously, MXene@LDH/EP contributes to the enhanced flame retardancy compared to EP, resulting in a 46.5% reduction in the total heat release (THR). In summary, this work provides a promising candidate advanced electronic packaging material for high-power density electronic packaging.

13.
Neuropharmacology ; 244: 109799, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38008374

RESUMO

DNA demethylation mediated by ten-eleven translocation 1 (TET1) is a critical epigenetic mechanism in which gene expression is regulated via catalysis of 5-methylcytosine to 5-hydroxymethylcytosine. Previously, we demonstrated that TET1 is associated with the genesis of chronic inflammatory pain. However, how TET1 participates in enhanced nociceptive responses in chronic pain remains poorly understood. Here, we report that conditional knockout of Tet1 in dorsal horn neurons via intrathecal injection of rAAV-hSyn-Cre in Tet1fl/fl mice not only reversed the inflammation-induced upregulation of synapse-associated proteins (post-synaptic density protein 95 (PSD95) and synaptophysin (SYP)) in the dorsal horn but also ameliorated abnormalities in dendritic spine morphology and alleviated pain hypersensitivities. Pharmacological blockade of TET1 by intrathecal injection of a TET1-specific inhibitor-Bobcat 339-produced similar results, as did knockdown of Tet1 by intrathecal injection of siRNA. Thus, our data strongly suggest that increased TET1 expression during inflammatory pain upregulates the expression of multiple synapse-associated proteins and dysregulates synaptic morphology in dorsal horn neurons, suggesting that Tet1 may be a potential target for analgesic strategies.


Assuntos
Dor , Corno Dorsal da Medula Espinal , Camundongos , Animais , Dor/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , Epigênese Genética , Analgésicos , Plasticidade Neuronal , Hiperalgesia/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo
14.
Eur J Nutr ; 63(1): 267-277, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37930363

RESUMO

PURPOSE: The study aimed to investigate the independent associations of dietary factors with cognitive impairment (CI) and physical frailty (PF) among Chinese older adults. METHODS: This study included 10,734 participants (mean age = 78.7 years) free of CI and PF at baseline from the Chinese Longitudinal Health Longevity Survey. Dietary intake was collected using a simplified food frequency questionnaire every 3-4 years. The Chinese version Mini-Mental State Examination was used to assess cognition function, participants with a score below 18 were defined as CI. PF was defined using the activities of daily living, instrumental activities of daily living, and functional limitation-related questions. The outcome was defined as the first onset of either CI or PF. Competing risk models were used to estimate the corresponding hazard ratios (HRs) and the 95% confidence intervals (95% CIs). RESULTS: During the study follow-up (mean = 8.1 years), a total of 1220 CI cases and 1451 PF cases were newly identified. Higher frequency of fruits intake was associated with a lower hazard of CI (HR = 0.75, 95% CI 0.58-0.97), whereas higher intake of preserved vegetables demonstrated an opposite association (HR = 1.23, 95% CI 1.07-1.42). In terms of PF, we observed a lower risk associated with higher meat and poultry intake (HR = 0.72, 95% CI 0.61-0.88). In particular, a significant protective association of fish and aquatic products intake with PF was observed among participants with ≥ 28 natural teeth (HR = 0.52, 95% CI 0.27-0.99). CONCLUSION: Our findings suggest divergent roles of major dietary factors in the development of CI and PF among Chinese older adults.


Assuntos
Disfunção Cognitiva , Fragilidade , Humanos , Idoso , Fragilidade/epidemiologia , Atividades Cotidianas , Estudos Prospectivos , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Cognição
15.
Ultrason Sonochem ; 102: 106727, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38113584

RESUMO

This study first employed ultrasonic-assisted fermentation of seaweed foot material with Lactiplantibacillus plantarum to produce Porphyra yezoensis sauce. The aim was to examine L. plantarum's growth and metabolism of nutritional components at different growth stages under low- (133.99 W/L) and high-ultrasonic power densities (169.17 W/L). After 24-h fermentation, L. plantarum exhibited a 21.32 % increase in the sonicated P. yezoensis sauce at 133.99 W/L and the logarithmic growth phase compared to that at 169.17 W/L. In addition, compared to the non-sonicated sauce, total phenolic and flavonoid contents increased by around 58 % and 27 % in sonicated sauce at 133.99 W/L, reaching 92.38 mg GEA/g DW and 111.08 mg RE/g DW, respectively. Principal Component Analysis (PCA) of the evaluation criteria for different fermentation stages under 133.99 W/L power ultrasonication revealed that the P. yezoensis sauce generated more phenolic compounds and exhibited stronger antioxidant capabilities in the sonicated sample at the logarithmic phase of L. plantarum. Compared to the traditional treated P. yezoensis sauce, the content of free amino acids was significantly increased in sonicated sauce, especially for logarithmic phase. Finally, GC-IMS analysis demonstrated that the ultrasonication at logarithmic phase released more volatile compounds compared to the non-sonicated sauce. This led to a reduction in the fishy odour of the Porphyra yezoensis sauce and an improved release of favourable flavour compounds.


Assuntos
60578 , Porphyra , Alga Marinha , Fermentação , Porphyra/química , Porphyra/metabolismo , Alimentos , Alga Marinha/química
17.
Front Bioeng Biotechnol ; 11: 1305582, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38047284

RESUMO

Lipoxygenase (LOX) holds significant promise for food and pharmaceutical industries. However, albeit its application has been hampered by low catalytic activity and suboptimal thermostability. To address the drawbacks, a directed evolution strategy was explored to enhance the catalytic activity and thermostability of LOX from Enterovibrio norvegicus (EnLOX) for the first time. After two rounds of error-prone polymerase chain reaction (error-prone PCR) and one generations of sequential DNA shuffling, all of four different mutants showed a significant increase in the specific activity of EnLOX, ranging from 132.07 ± 9.34 to 330.17 ± 18.54 U/mg. Among these mutants, D95E/T99A/A121H/S142N/N444W/S613G (EAHNWG) exhibited the highest specific activity, which was 8.25-fold higher than the wild-type enzyme (WT). Meanwhile, the catalytic efficiency (K cat /K m) of EAHNWG was also improved, which was 13.61 ± 1.67 s-1 µM-1, in comparison to that of WT (4.83 ± 0.38 s-1 µM-1). In addition, mutant EAHNWG had a satisfied thermostability with the t 1/2,50 °C value of 6.44 ± 0.24 h, which was 0.4 h longer than that of the WT. Furthermore, the molecular dynamics simulation and structural analysis demonstrated that the reduction of hydrogen bonds number, the enhancement of hydrophobic interactions in the catalytic pocket, and the improvement of flexibility of the lid domain facilitated structural stability and the strength of substrate binding capacity for improved thermal stability and catalytic efficiency of mutant LOX after directed evolution. Overall, these results could provide the guidance for further enzymatic modification of LOX with high catalytic performance for industrial application.

18.
Acta Pharm Sin B ; 13(11): 4638-4654, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37969733

RESUMO

Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins. Here, we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain of bioactive steroidal saponins from a widely known medicinal plant Paris polyphylla var. yunnanensis. Among them, a 2'-O-rhamnosyltransferase and three 6'-O-glucosyltrasferases catalyzed a cascade of glycosylation to produce steroidal diglycosides and triglycosides, respectively. These UDP-glycosyltransferases showed astonishing substrate promiscuity, resulting in the generation of a panel of 24 terpenoid glycosides including 15 previously undescribed compounds. A mutant library containing 44 variants was constructed based on the identification of critical residues by molecular docking simulations and protein model alignments, and a mutant UGT91AH1Y187A with increased catalytic efficiency was obtained. The steroidal saponins exhibited remarkable antifungal activity against four widespread strains of human pathogenic fungi attributed to ergosterol-dependent damage of fungal cell membranes, and 2'-O-rhamnosylation appeared to correlate with strong antifungal effects. The findings elucidated the biosynthetic machinery for their production of steroidal saponins and revealed their potential as new antifungal agents.

19.
Food Res Int ; 174(Pt 2): 113663, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37981365

RESUMO

This study aimed to investigate the effect of static magnetic field (SMF, 0-10 mT) on the quality of rice dumplings subjected to 7, 14, 21, and 28 freeze-thaw cycles. The underlying mechanism was explored by monitoring changes in water phase transition, water distribution, and structural and physicochemical properties of rice flour. Results suggested that SMF enables the formation of small ice crystals by accelerating freezing rate, shortening phase transition time, and increasing bound water content, which attributes to reducing the mechanical damage on starch granules and thus improves the quality of frozen rice dumpling. After 7-28 freeze-thaw cycles, SMF treatment increased the whiteness by 0.08-1.58, reduced the cracking ratio by 1.67 %-8.34 %, decreased the water loss ratio by 0-0.75 %, and significantly improved the texture of cooked rice dumplings. This study confirmed the feasibility of SMF in improving the quality of rice dumpling, which contributes to expanding the applications of magnetic freezer in the preservation of starch-based foods.


Assuntos
Oryza , Congelamento , Oryza/química , Farinha , Água/química , Amido/química
20.
Foods ; 12(22)2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-38002203

RESUMO

This investigation examined how the Bacillus vallismortis laccase (rBVL-MRL522) influenced the physicochemical characteristics, structural attributes, and functional capabilities of both dough and noodles. Incorporating rBVL-MRL522 (1 U/g) did not lead to a substantial change in the water absorption of wheat flour. However, the introduction of rBVL-MRL522 caused a significant elongation in the formation time of wheat flour dough, extending it by 88.9%, and also resulted in a 50% increase in the stabilization duration of wheat flour dough. Furthermore, adding rBVL-MRL522 led to a proportional rise in both the elastic and viscous moduli (G'' of the dough, signifying that r-BVL (rBVL-MRL522) has a beneficial effect on the gluten strength of the dough. Integrating rBVL-MRL522 promoted the consolidation of the gluten-based cross-linked structure within the dough, decreasing the size of starch particles and, more evenly, the dispersion of these starch particles. In the noodle processing, adding rBVL-MRL522 at a rate of 1 U/g raised the L* value of the noodles by 2.34 units compared to the noodles prepared without the inclusion of rBVL-MRL522. Using a greater amount of rBVL-MRL522 (2 U/g) substantially increased the hardness of the noodles by 51.31%. Additionally, rBVL-MRL522 showed a noteworthy enhancement in the elasticity, cohesiveness, and chewiness of the noodles. In conclusion, rBVL-MRL522 promoted the cross-linking gluten, leading to a more extensive and condensed three-dimensional network structure in raw and cooked noodles. As a result, this study offers valuable insights into the environmentally friendly processing of dough and associated products.

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