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1.
Nature ; 600(7887): 59-63, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34666339

RESUMEN

Mare volcanics on the Moon are the key record of thermo-chemical evolution throughout most of lunar history1-3. Young mare basalts-mainly distributed in a region rich in potassium, rare-earth elements and phosphorus (KREEP) in Oceanus Procellarum, called the Procellarum KREEP Terrane (PKT)4-were thought to be formed from KREEP-rich sources at depth5-7. However, this hypothesis has not been tested with young basalts from the PKT. Here we present a petrological and geochemical study of the basalt clasts from the PKT returned by the Chang'e-5 mission8. These two-billion-year-old basalts are the youngest lunar samples reported so far9. Bulk rock compositions have moderate titanium and high iron contents  with KREEP-like rare-earth-element and high thorium concentrations. However, strontium-neodymium isotopes indicate that these basalts were derived from a non-KREEP mantle source. To produce the high abundances of rare-earth elements and thorium, low-degree partial melting and extensive fractional crystallization are required. Our results indicate that the KREEP association may not be a prerequisite for young mare volcanism. Absolving the need to invoke heat-producing elements in their source implies a more sustained cooling history of the lunar interior to generate the Moon's youngest melts.

2.
Nucleic Acids Res ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38967023

RESUMEN

In the type III CRISPR system, cyclic oligoadenylate (cOA) molecules act as second messengers, activating various promiscuous ancillary nucleases that indiscriminately degrade host and viral DNA/RNA. Conversely, ring nucleases, by specifically cleaving cOA molecules, function as off-switches to protect host cells from dormancy or death, and allow viruses to counteract immune responses. The fusion protein Csx1-Crn2, combining host ribonuclease with viral ring nuclease, represents a unique self-limiting ribonuclease family. Here, we describe the structures of Csx1-Crn2 from the organism of Marinitoga sp., in both its full-length and truncated forms, as well as in complex with cA4. We show that Csx1-Crn2 operates as a homo-tetramer, a configuration crucial for preserving the structural integrity of the HEPN domain and ensuring effective ssRNA cleavage. The binding of cA4 to the CARF domain triggers significant conformational changes across the CARF, HTH, and into the HEPN domains, leading the two R-X4-6-H motifs to form a composite catalytic site. Intriguingly, an acetate ion was found to bind at this composite site by mimicking the scissile phosphate. Further molecular docking analysis reveals that the HEPN domain can accommodate a single ssRNA molecule involving both R-X4-6-H motifs, underscoring the importance of HEPN domain dimerization for its activation.

3.
Nucleic Acids Res ; 51(5): 2485-2495, 2023 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-36807980

RESUMEN

The cyclic oligoadenylates (cOAs) act as second messengers of the type III CRISPR immunity system through activating the auxiliary nucleases for indiscriminate RNA degradation. The cOA-degrading nucleases (ring nucleases) provide an 'off-switch' regulation of the signaling, thereby preventing cell dormancy or cell death. Here, we describe the crystal structures of the founding member of CRISPR-associated ring nuclease 1 (Crn1) Sso2081 from Saccharolobus solfataricus, alone, bound to phosphate ions or cA4 in both pre-cleavage and cleavage intermediate states. These structures together with biochemical characterizations establish the molecular basis of cA4 recognition and catalysis by Sso2081. The conformational changes in the C-terminal helical insert upon the binding of phosphate ions or cA4 reveal a gate-locking mechanism for ligand binding. The critical residues and motifs identified in this study provide a new insight to distinguish between cOA-degrading and -nondegrading CARF domain-containing proteins.


Asunto(s)
Proteínas Asociadas a CRISPR , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Sistemas de Mensajero Secundario , Transducción de Señal , Endonucleasas/metabolismo , Iones/metabolismo , Sistemas CRISPR-Cas , Proteínas Asociadas a CRISPR/metabolismo
4.
Pharmacology ; 108(4): 344-358, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37231999

RESUMEN

INTRODUCTION: Acid-related inflammatory damage to the esophageal epithelium is a key component in the development of gastroesophageal reflux disease. Melatonin (MT) is considered as a potential therapeutic agent, but its molecular mechanism is unknown. METHODS: The expression of HIF-1α and pyroptosis-related genes (NLRP3, caspase-1, IL-1ß, and IL-18) was analyzed using bioinformatics methods in GSE63401 and validated using quantitative real-time polymerase chain reaction and Western blot in an HEEC inflammation model induced by deoxycholic acid (DCA). Hoechst 33342/PI double staining was used to assess the level of pyroptosis, and the effect of MT treatment was observed. The miRDB, TarBase, miRcode, miRNet, and ENCORI databases were used to predict the long non-coding RNA (lncRNA) targeting HIF-1α and the RNA-binding protein interacting with the lncRNA. RESULTS: The expressions of Moloney leukemia virus 10 (MOV10), lncRNA NEAT1, HIF-1α, and pyroptosis-related genes were upregulated, while the expression of miR-138-5p was downregulated in acidic DCA-induced HEEC inflammation. MOV10 may bind to lncRNA NEAT1 and stabilize its expression, while lncRNA NEAT1 upregulates the expression of HIF-1α by adsorbing miR-138-5p to activate the NLRP3 inflammasome. However, MT pretreatment can significantly inhibit these processes. CONCLUSIONS: MOV10-lncRNA NEAT1/miR-138-5p/HIF-1α/NLRP3 axis plays a crucial role in acid-related esophageal epithelial inflammatory injury, and MT may exert an esophageal protective effect by inhibiting the pathway.


Asunto(s)
Melatonina , MicroARNs , ARN Largo no Codificante , MicroARNs/genética , MicroARNs/metabolismo , Piroptosis , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proliferación Celular/genética , Células Epiteliales/metabolismo
5.
BMC Anesthesiol ; 23(1): 298, 2023 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-37667179

RESUMEN

PURPOSE: Transfusing red blood cells promptly corrects anemia and improves tissue oxygenation in around 40% of patients hospitalized in the intensive care unit (ICU) after major surgical operations. This study's goal is to investigate how blood transfusions affect the mortality rates of patients after major surgery who are hospitalized in the ICU. METHODS: Retrospective research was done on recently hospitalized patients who had major procedures in the ICU between October 2020 and February 2022 at the Huanggang Central Hospital of Yangtze University, China. The patients' prognoses at three months were used to classify them as either survivors or deceased. Patient demographic information, laboratory results, and blood transfusion histories were acquired, and the outcomes of the two groups were compared based on the differences. Univariate and multivariate logistic regression analyses were used to examine the prognosis of surgical disease patients first admitted to the ICU. The receiver operating characteristic (ROC) curve was used to evaluate the predictive power of each risk factor. The relationship between transfusion frequency, transfusion modality, and patient outcome was examined using Spearman's correlation analysis. RESULTS: Data from 384 patients was included in the research; of them, 214 (or 55.7%) died within three months of their first stay in the ICU. The death group had higher scores on the Acute Physiology and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) than the survival group did (all P < 0.05); the death group also had lower scores on the Glasgow Coma Scale, systolic blood pressure, hemoglobin, platelet distribution width, and blood transfusion ratio. Multivariate logistic regression analysis revealed an odds ratio (OR) of 1.654 (1.281-1.989), a 95% confidence interval (CI) of 1.440 (1.207-1.701), and a P value of 0.05 for death in patients undergoing major surgery who were hospitalized to the intensive care unit (ICU). Areas under the ROC curve (AUC) of 0.836, 0.799, and 0.871, respectively, and 95% CIs of 0.796-0.875, 0.755-0.842, and 0.837-0.904, respectively, all P0.05, had significant predictive value for patients initially admitted to the ICU and for APACHE II score > = 12 points, SOFA score > = 6, and blood transfusion. When all three indicators were used jointly to predict a patient's prognosis after major surgery, the accuracy increased to 86.4% (sensitivity) and 100% (specificity). There was a negative correlation between the number of blood transfusions a patient had and their outcome (r = 0.605, P < 0.001) and death (r = 0.698, P < 0.001). CONCLUSION: A higher initial ICU APACHE II score, SOFA score, and a number of blood transfusions were associated with improved survival for patients undergoing major surgical operations. Patients' death rates have increased with the increase in the frequency and variety of blood transfusions.


Asunto(s)
Hospitalización , Hospitales , Humanos , Estudios Retrospectivos , Transfusión Sanguínea , Unidades de Cuidados Intensivos
6.
J Exp Bot ; 73(8): 2698-2713, 2022 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-35137020

RESUMEN

Phytosulfokine-α (PSK-α), a tyrosine-sulfated pentapeptide with the sequence YSO3IYSO3TQ, is widely distributed across the plant kingdom and plays multiple roles in plant growth, development, and immune response. Here, we report a novel type of phytosulfokine, PSK-δ, and its precursor proteins (MtPSKδ, LjPSKδ, and GmPSKδ1), specifically from legume species. The sequence YSO3IYSO3TN of sulfated PSK-δ peptide is different from PSK-α at the last amino acid. Expression pattern analysis revealed PSK-δ-encoding precursor genes to be expressed primarily in legume root nodules. Specifically, in Medicago truncatula, MtPSKδ expression was detected in root cortical cells undergoing nodule organogenesis, in nodule primordia and young nodules, and in the apical region of mature nodules. Accumulation of sulfated PSK-δ peptide in M. truncatula nodules was detected by LC/MS. Application of synthetic PSK-δ peptide significantly increased nodule number in legumes. Similarly, overexpression of MtPSKδ in transgenic M. truncatula markedly promoted symbiotic nodulation. This increase in nodule number was attributed to enhanced nodule organogenesis induced by PSK-δ. Additional genetic evidence from the MtPSKδ mutant and RNA interference assays suggested that the PSK-δ and PSK-α peptides function redundantly in regulating nodule organogenesis. These results suggest that PSK-δ, a legume-specific novel type of phytosulfokine, promotes symbiotic nodulation by enhancing nodule organogenesis.


Asunto(s)
Medicago truncatula , Proteínas de Plantas , Regulación de la Expresión Génica de las Plantas , Medicago truncatula/metabolismo , Péptidos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nodulación de la Raíz de la Planta/genética , Nódulos de las Raíces de las Plantas/metabolismo , Simbiosis/fisiología
7.
Anim Biotechnol ; 33(6): 1190-1197, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33635178

RESUMEN

The genetic diversity and population structures of five Chongqing local chicken populations were investigated using by 24 microsatellite markers. Results revealed that the mean number of alleles (NA) ranged from 7.08 (Daninghe chicken, DN) to 8.46 (Nanchuan chicken, NC). The highest observed heterozygosity (HO) and expected heterozygosity (HE) were observed in DN (HO = 0.7252; HE = 0.7409) and the lowest HO and HE were observed in XS (Xiushan native chicken [XS], HO = 0.5910 and HE = 0.6697). The inbreeding coefficient (FIS) within population ranged from 0.022 (DN) to 0.119 (XS). Among the 24 microsatellite markers, four loci (MCW0111, MCW0016, ADL0278, and MCW0104) deviated from the Hardy-Weinberg equilibrium in all the studied populations. The results of population polygenetic analysis based on Nei's genetic distance and STRUCTURE software showed that the clustering of the five populations was incomplete consistent with geographical distribution. Moreover, a large number of gene flows were widespread among different populations, suggesting that genetic material exchanges occurred due to human activities and migration which was also verified by PCoA. In summary, this study preliminarily showed that Chongqing local chicken populations had rich genetic diversity and remarkable genetic divergence, but still high risk in conversion. These findings would be useful to the management of conservation strategies and the utilization of local chicken populations in further.


Asunto(s)
Pollos , Variación Genética , Humanos , Animales , Pollos/genética , Filogenia , Variación Genética/genética , Repeticiones de Microsatélite/genética , Alelos
8.
Nat Chem Biol ; 15(12): 1241-1248, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31611704

RESUMEN

The Holliday junction (HJ) is a key intermediate during homologous recombination and DNA double-strand break repair. Timely HJ resolution by resolvases is critical for maintaining genome stability. The mechanisms underlying sequence-specific substrate recognition and cleavage by resolvases remain elusive. The monokaryotic chloroplast 1 protein (MOC1) specifically cleaves four-way DNA junctions in a sequence-specific manner. Here, we report the crystal structures of MOC1 from Zea mays, alone or bound to HJ DNA. MOC1 uses a unique ß-hairpin to embrace the DNA junction. A base-recognition motif specifically interacts with the junction center, inducing base flipping and pseudobase-pair formation at the strand-exchanging points. Structures of MOC1 bound to HJ and different metal ions support a two-metal ion catalysis mechanism. Further molecular dynamics simulations and biochemical analyses reveal a communication between specific substrate recognition and metal ion-dependent catalysis. Our study thus provides a mechanism for how a resolvase turns substrate specificity into catalytic efficiency.


Asunto(s)
Cloroplastos/metabolismo , Resolvasas de Unión Holliday/metabolismo , Proteínas de Plantas/metabolismo , Resolvasas de Unión Holliday/química , Simulación de Dinámica Molecular , Conformación Proteica , Especificidad por Sustrato
9.
Microb Cell Fact ; 20(1): 11, 2021 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-33422055

RESUMEN

BACKGROUND: D-Amino acids are increasingly used as building blocks to produce pharmaceuticals and fine chemicals. However, establishing a universal biocatalyst for the general synthesis of D-amino acids from cheap and readily available precursors with few by-products is challenging. In this study, we developed an efficient in vivo biocatalysis system for the synthesis of D-amino acids from L-amino acids by the co-expression of membrane-associated L-amino acid deaminase obtained from Proteus mirabilis (LAAD), meso-diaminopimelate dehydrogenases obtained from Symbiobacterium thermophilum (DAPDH), and formate dehydrogenase obtained from Burkholderia stabilis (FDH), in recombinant Escherichia coli. RESULTS: To generate the in vivo cascade system, three strategies were evaluated to regulate enzyme expression levels, including single-plasmid co-expression, double-plasmid co-expression, and double-plasmid MBP-fused co-expression. The double-plasmid MBP-fused co-expression strain Escherichia coli pET-21b-MBP-laad/pET-28a-dapdh-fdh, exhibiting high catalytic efficiency, was selected. Under optimal conditions, 75 mg/mL of E. coli pET-21b-MBP-laad/pET-28a-dapdh-fdh whole-cell biocatalyst asymmetrically catalyzed the stereoinversion of 150 mM L-Phe to D-Phe, with quantitative yields of over 99% ee in 24 h, by the addition of 15 mM NADP+ and 300 mM ammonium formate. In addition, the whole-cell biocatalyst was used to successfully stereoinvert a variety of aromatic and aliphatic L-amino acids to their corresponding D-amino acids. CONCLUSIONS: The newly constructed in vivo cascade biocatalysis system was effective for the highly selective synthesis of D-amino acids via stereoinversion.


Asunto(s)
Aminoácido Oxidorreductasas/metabolismo , Aminoácidos/metabolismo , Aminohidrolasas/metabolismo , Formiato Deshidrogenasas/metabolismo , Biocatálisis , Burkholderia/enzimología , Clostridiales/enzimología , Proteus mirabilis/enzimología , Estereoisomerismo , Especificidad por Sustrato
10.
Biochem Biophys Res Commun ; 523(1): 66-71, 2020 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-31831172

RESUMEN

Leguminous root nodules specifically induced by rhizobium species fix nitrogen gas to gain nitrogen sources, which is important in sustainable agriculture and ecological balance. Several peptide signals are reported to be involved in regulation of legume nodule number and development. There are fifteen genes coding Root Meristem Growth Factor (RGF) peptide in Medicago truncatula, herein we find the expression of MtRGF3 is significantly induced by Sinorhizobium meliloti with production of Nod factors. The gene promoter is active in nodule primordia, young nodules and the meristem region of mature nodules. Knock-down (RNAi) roots of the gene (MtRGF3-RNAi) formed more root nodules than the empty vector control, and the nodule number decreased in MtRGF3-overexpressing (MtRGF3-OX) roots. Exogenous addition of the synthesized peptide significantly promoted primary root growth and inhibited lateral root emergence, in addition, the peptide application reduced the number of infection threads, nodule primordia and root nodules of M. truncatula. We also found that tyrosine sulfation determines the biological activity of MtRGF3 functioning in nodulation process, and MtRGF3 peptide negatively regulates nodulation in a dosage manner. These results demonstrate that the MtRGF3 peptide is a novel regulator during nodulation of Medicago trucatula.


Asunto(s)
Medicago truncatula/metabolismo , Péptidos/metabolismo , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Medicago truncatula/genética , Péptidos/genética , Proteínas de Plantas/genética , Nodulación de la Raíz de la Planta/genética , Raíces de Plantas/metabolismo , Sinorhizobium meliloti/metabolismo , Factores de Transcripción/genética
12.
Sensors (Basel) ; 20(18)2020 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-32957619

RESUMEN

Accurate analysis using a simple and rapid procedure is always the most important pursuit of analytical chemists. In this study, a new sample preparation procedure, namely the shaker cup (SH) method, was designed and compared with two sample preparation procedures, commonly used in the laboratory, from three aspects: homogeneity of the sample-flux mixture, potential for sample contamination, and sample preparation time. For the three methods, a set of 54 certified reference materials (CRMs) was used to establish the calibration curves, while another set of 19 CRMs was measured to validate the results. In the calibration procedures, the matrix effects were corrected using the theoretical alpha coefficient method combined with the experimental coefficient method. The data of the major oxides (SiO2, TiO2, Al2O3, TFe2O3, MnO, MgO, CaO, Na2O, K2O, and P2O5) and minor elements (Cr, Cu, Ba, Ni, Sr, V, Zr, and Zn) obtained by wavelength dispersive X-ray fluorescence spectroscopy (WD-XRF) were compared using two derivative equations based on the findings by Laurence Whitty-Léveillé. The results revealed that the WD-XRF measured values using the SH method best agreed with the values recommended in the literature.

13.
BMC Biotechnol ; 18(1): 25, 2018 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-29728076

RESUMEN

BACKGROUND: Human chromogranin A (CgA) is a ~ 49 kDa secreted protein mainly from neuroendocrine cells and endocrine cells. The CgA values in the diagnosis of tumor, and in the potential role in prognostic and predictive tumor as a biomarker. RESULTS: The synthesized gene of CgA coding area was cloned and expressed as fusion protein CgA-His in procaryotic system. Then the purified CgA-His protein was mixed with QuickAntibody-Mouse5W adjuvant, and injected into mice. The CgA-His protein was also used as coating antigen to determine the antiserum titer. By screening, a stable cell line named 4E5, which can generate anti-CgA monoclonal antibody (mAb), was obtained. The isotype of 4E5 mAb was IgG2b, and the chromosome number was 102 ± 4. Anti-CgA mAb was purified from ascites fluid, and the affinity constant reached 9.23 × 109 L/mol. Furthermore, the specificity of the mAb was determined with ELISA, western blot and immunohistochemistry. Results indicated that the mAb 4E5 was able to detect chromogranin A specifically and sensitively. CONCLUSIONS: A sensitive and reliable method was successfully developed for rapid production of anti-CgA mAb for immunohistochemistry diagnosis in this study, and the current study also provides conclusive guidelines for preparation of mAbs and implements in immunohistochemistry diagnosis.


Asunto(s)
Anticuerpos Monoclonales/biosíntesis , Cromogranina A/inmunología , Neoplasias/diagnóstico , Animales , Anticuerpos Monoclonales/genética , Especificidad de Anticuerpos , Humanos , Inmunohistoquímica , Ratones Endogámicos BALB C
14.
Bioorg Med Chem ; 24(22): 6040-6047, 2016 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-27713013

RESUMEN

A series of ß-alkylaminoporphyrins conjugated with different amines at ß position (D1-D3) or with electron-donating and electron-withdrawing substituents at phenyl position (D4-D6) were synthesized. Their photophysical and photochemical properties, intracellular localization, photocytotoxicities in vitro and vivo were also investigated. All target compounds exhibited no cytotoxicities in the dark and excellent photocytotoxicities against HeLa cells. Among them, D6 showed the highest phototoxicity and the lowest dark toxicity, which was more phototoxic than Hematoporphyrin monomethyl ether (HMME). In addition, D6 exhibited best photodynamic antitumor efficacy on BALB/c nude mice bearing HeLa tumor. Therefore, D6 is a powerful and promising antitumor photosensitizer for photodynamic therapy.


Asunto(s)
Antineoplásicos/farmacología , Fotoquimioterapia , Porfirinas/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Células HeLa , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Estructura Molecular , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Procesos Fotoquímicos , Porfirinas/síntesis química , Porfirinas/química , Relación Estructura-Actividad
15.
Bioprocess Biosyst Eng ; 39(4): 533-43, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26753831

RESUMEN

In this study, an effective pretreatment of dilute NaOH-soaked chestnut shell (CNS) with glycerol-HClO4-water (88.8:1.2:10, w/w/w) media at 130 °C for 30 min was successfully demonstrated. Results revealed that the combination pretreatment removed 66.0 % of lignin and 73.7 % of hemicellulose in untreated CNS. The changes in the structural features (crystallinity, morphology, and porosity) of the solid residue of CNS were characterized with Fourier transform infrared spectroscopy, fluorescent microscope, scanning electron microscopy, and X-ray diffraction. Biotransformation of glycerol-HClO4-water pretreated-NaOH-soaked CNS (50 g/L) with a cocktail of enzymes for 72 h, the reducing sugars and glucose were 39.7 and 33.4 g/L, respectively. Moreover, the recovered hydrolyzates containing 20 g/L glucose had no inhibitory effects on the ethanol-fermenting microorganism, and the ethanol production was 0.45 g/g glucose within 48 h. In conclusion, this combination pretreatment shows promise as pretreatment solvent for wheat straw, although the in-depth exploration of this subject is needed.


Asunto(s)
Etanol/química , Glucosa/química , Glicerol/química , Juglans/química , Percloratos/química , Hidróxido de Sodio/química , Lignina/química , Polisacáridos/química , Agua/química
16.
Biotechnol Lett ; 37(1): 183-8, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25214230

RESUMEN

Rhodococcus sp. CGMCC 4911 transformed 1,3-propanediol cyclic sulfate (1,3-PDS) and its derivatives into corresponding diols. Ethylene sulfate, glycol sulfide, 1,3-PDS, and 1,2-propanediol cyclic sulfate were effectively hydrolyzed with growing cells. (R)-1,2-Propanediol (>99 % e.e.) was obtained at 44 % yield with growing cells. Glycol sulfide, ethylene sulfate, and 1,3-PDS were converted into the corresponding diols at 94.6, 96.3, and 98.3 %, respectively. Optimal reaction conditions with lyophilized resting cells were 30 °C, pH 7.5, and cell dosage 17.9 mg cell dry wt/ml. 1,3-Propanediol was obtained from 50 mM 1,3-PDS at 97.2 % yield by lyophilized cells after 16 h. Lyophilized cells were entrapped in calcium alginate with a half-life of 263 h at 30 °C, and the total operational time of the immobilized biocatalysts could reach over 192 h with a high conversion rate.


Asunto(s)
Glicoles de Propileno/metabolismo , Rhodococcus/metabolismo , Sulfatos/metabolismo , Proteínas Bacterianas/metabolismo , Biotecnología , Biotransformación , Células Inmovilizadas , Concentración de Iones de Hidrógeno , Glicoles de Propileno/análisis , Rhodococcus/enzimología , Sulfatasas/metabolismo , Sulfatos/análisis
17.
Nat Commun ; 15(1): 5140, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886375

RESUMEN

Holliday junction resolution is a crucial process in homologous recombination and DNA double-strand break repair. Complete Holliday junction resolution requires two stepwise incisions across the center of the junction, but the precise mechanism of metal ion-catalyzed Holliday junction cleavage remains elusive. Here, we perform a metal ion-triggered catalysis in crystals to investigate the mechanism of Holliday junction cleavage by MOC1. We capture the structures of MOC1 in complex with a nicked Holliday junction at various catalytic states, including the ground state, the one-metal ion binding state, and the two-metal ion binding state. Moreover, we also identify a third metal ion that may aid in the nucleophilic attack on the scissile phosphate. Further structural and biochemical analyses reveal a metal ion-mediated allosteric regulation between the two active sites, contributing to the enhancement of the second strand cleavage following the first strand cleavage, as well as the precise symmetric cleavage across the Holliday junction. Our work provides insights into the mechanism of metal ion-catalyzed Holliday junction resolution by MOC1, with implications for understanding how cells preserve genome integrity during the Holliday junction resolution phase.


Asunto(s)
ADN Cruciforme , ADN Cruciforme/metabolismo , ADN Cruciforme/química , ADN Cruciforme/genética , Metales/metabolismo , Metales/química , Resolvasas de Unión Holliday/metabolismo , Resolvasas de Unión Holliday/química , Dominio Catalítico , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Cristalografía por Rayos X , Iones/metabolismo , Roturas del ADN de Doble Cadena , Modelos Moleculares , Regulación Alostérica
18.
Bioresour Technol ; 399: 130579, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38479628

RESUMEN

An effective deep eutectic solvent (DES) and Iron(III) chloride (FeCl3) combination pretreatment system was developed to improve the removal efficiency of lignin and hemicellulose from corn stover (CS) and enhance its saccharification. N-(2-hydroxyethyl)ethylenediamine (NE) was selected as the hydrogen-bond-donor for preparing ChCl-based DES (ChCl:NE), and a mixture of ChCl:NE (60 wt%) and FeCl3 (0.5 wt%) was utilized for combination pretreatment of CS at 110 ℃ for 50 min. FeCl3/ChCl:NE effectively removed lignin (87.0 %) and xylan (55.9 %) and the enzymatic hydrolysis activity of FeCl3/ChCl:NE-treated CS was 5.5 times that of CS. The reducing sugar yield of pretreated CS was 98.6 %. FeCl3/ChCl:NE significantly disrupted the crystal structure of cellulose in CS and improved the removal of lignin and hemicellulose, enhancing the conversion of cellulose and hemicellulose into monomeric sugars. Overall, this combination of FeCl3 and DES pretreatment methods has high application potential for the biological refining of lignocellulose.


Asunto(s)
Compuestos Férricos , Lignina , Lignina/química , Cloruros , Zea mays/química , Disolventes Eutécticos Profundos , Solventes/química , Biomasa , Celulosa/química , Xilanos , Hidrólisis
19.
Poult Sci ; 103(2): 103271, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38064882

RESUMEN

Multiple outbreaks of avian infectious laryngotracheitis (ILT) in chickens, both domestically and internationally, have been directly correlate to widespread vaccine use in affected countries and regions. Phylogenetic and recombination event analyses have demonstrated that avian infectious laryngotracheitis virus (ILTV) field strains are progressively evolving toward the chicken embryo-origin (CEO) vaccine strain. Even with standardized biosecurity measures and effective prevention and control strategies implemented on large-scale farms, continuous ILT outbreaks result in significant economic losses to the poultry industry worldwide. These outbreaks undoubtedly hinder efforts to control and eradicate ILTV in the future. In this study, an ILTV isolate was successfully obtained by laboratory PCR detection and virus isolation from chickens that exhibited dyspnea and depression on a broiler farm in Hubei Province, China. The isolated strain exhibited robust propagation on chorioallantoic membranes of embryonated eggs, but failed to establish effective infection in chicken hepatocellular carcinoma (LMH) cells. Phylogenetic analysis revealed a unique T441P point mutation in the gJ protein of the isolate. Animal experiments confirmed the virulence of this strain, as it induced mortality in 6-wk-old chickens. This study expands current understanding of the epidemiology, genetic variations, and pathogenicity of ILTV isolates circulating domestically, contributing to the elucidate of ILTV molecular basis of pathogenicity and development of vaccine.


Asunto(s)
Infecciones por Herpesviridae , Herpesvirus Gallináceo 1 , Enfermedades de las Aves de Corral , Vacunas Virales , Embrión de Pollo , Animales , Pollos , Herpesvirus Gallináceo 1/genética , Virulencia , Filogenia , Óvulo , Infecciones por Herpesviridae/epidemiología , Infecciones por Herpesviridae/veterinaria , Enfermedades de las Aves de Corral/prevención & control
20.
Psychol Res Behav Manag ; 15: 3497-3511, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36505670

RESUMEN

Purpose: As an important channel to search and share information, professional virtual community (PVC) has become one of the main channels for Chinese young netizens to search information and socialize. However, despite many researches on PVC have been conducted in various fields, there is still a lack of researches on young netizens in China, who are in the stage of online social networking booming with countless PVCs but many of them are non-effective. Moreover, there are few studies to explore explicit paths to obtain the effective information sharing or sustainable development of PVC. Therefore, based on this research gap and social cognitive theory, this study explored PVC information sharing among Chinese young netizens combining the external factors and the individual factors, and attempted to obtain the paths to the effective PVC information sharing. Methods: An online survey was conducted through snowball sampling in China, and 407 samples from 15 different PVCs were confirmed. By using fuzzy-set qualitative comparative analysis (fsQCA) with software fs/QCA 3.0, this study attempted to explore the casual configurations that achieve high and non-high effectiveness of PVC information sharing among Chinese young netizens. Results: Three types of equivalent configurations that can achieve high effectiveness of PVC information sharing are obtained; Four types of equivalent configurations that can achieve non-high effectiveness of PVC information sharing are obtained. Furthermore, the findings indicate that the expertise of PVC and challenge-skill balance of members are the primary factors in PVC information sharing. Conclusion: The findings of this study provide that the paths to high and non-high effectiveness of PVC information sharing, which is beneficial to the management and development of PVC. Furthermore, it is helpful for netizens to find and enjoy the PVCs with high quality when they need them. The management of public opinion and how to design web pages to improve the user experience can also be carried out from this perspective.

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