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1.
Nature ; 600(7887): 59-63, 2021 12.
Article in English | MEDLINE | ID: mdl-34666339

ABSTRACT

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 ; 52(14): 8419-8430, 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-38967023

ABSTRACT

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.


Subject(s)
Bacterial Proteins , CRISPR-Associated Proteins , CRISPR-Cas Systems , Adenine Nucleotides/metabolism , Adenine Nucleotides/chemistry , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , CRISPR-Associated Proteins/metabolism , CRISPR-Associated Proteins/chemistry , CRISPR-Associated Proteins/genetics , Models, Molecular , Oligoribonucleotides , Protein Binding , Protein Domains , Protein Multimerization , Ribonucleases/metabolism , Ribonucleases/chemistry , Ribonucleases/genetics
3.
Nucleic Acids Res ; 51(5): 2485-2495, 2023 03 21.
Article in English | MEDLINE | ID: mdl-36807980

ABSTRACT

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.


Subject(s)
CRISPR-Associated Proteins , Clustered Regularly Interspaced Short Palindromic Repeats , Second Messenger Systems , Signal Transduction , Endonucleases/metabolism , Ions/metabolism , CRISPR-Cas Systems , CRISPR-Associated Proteins/metabolism
4.
Plant Cell Environ ; 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-39286964

ABSTRACT

Posttranslational tyrosine sulfation of peptides and proteins is catalysed by tyrosylprotein sulfotransferases (TPSTs). In Arabidopsis, tyrosine sulfation is essential for the activities of peptide hormones, such as phytosulfokine (PSK) and root meristem growth factor (RGF). Here, we identified a TPST-encoding gene, MtTPST, from model legume Medicago truncatula. MtTPST expression was detected in all organs, with the highest level in root nodules. A promoter:GUS assay revealed that MtTPST was highly expressed in the root apical meristem, nodule primordium and nodule apical meristem. The loss-of-function mutant mttpst exhibited a stunted phenotype with short roots and reduced nodule number and size. Application of both of the sulfated peptides PSK and RGF3 partially restored the defective root length of mttpst. The reduction in symbiotic nodulation in mttpst was partially recovered by treatment with sulfated PSK peptide. MtTPST-PSK module functions downstream of the Nod factor signalling to promote nodule initiation via regulating accumulation and/or signalling of cytokinin and auxin. Additionally, the small-nodule phenotype of mttpst, which resulted from decreased apical meristematic activity, was partially complemented by sulfated RGF3 treatment. Together, these results demonstrate that MtTPST, through its substrates PSK, RGF3 and other sulfated peptide(s), positively regulates nodule development and root growth.

5.
Pharmacology ; 108(4): 344-358, 2023.
Article in English | MEDLINE | ID: mdl-37231999

ABSTRACT

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.


Subject(s)
Melatonin , MicroRNAs , RNA, Long Noncoding , MicroRNAs/genetics , MicroRNAs/metabolism , Pyroptosis , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Gene Expression Regulation, Neoplastic , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Cell Proliferation/genetics , Epithelial Cells/metabolism
6.
BMC Anesthesiol ; 23(1): 298, 2023 09 04.
Article in English | MEDLINE | ID: mdl-37667179

ABSTRACT

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.


Subject(s)
Hospitalization , Hospitals , Humans , Retrospective Studies , Blood Transfusion , Intensive Care Units
7.
J Exp Bot ; 73(8): 2698-2713, 2022 04 18.
Article in English | MEDLINE | ID: mdl-35137020

ABSTRACT

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.


Subject(s)
Medicago truncatula , Plant Proteins , Gene Expression Regulation, Plant , Medicago truncatula/metabolism , Peptides/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Root Nodulation/genetics , Root Nodules, Plant/metabolism , Symbiosis/physiology
8.
Anim Biotechnol ; 33(6): 1190-1197, 2022 Nov.
Article in English | MEDLINE | ID: mdl-33635178

ABSTRACT

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.


Subject(s)
Chickens , Genetic Variation , Humans , Animals , Chickens/genetics , Phylogeny , Genetic Variation/genetics , Microsatellite Repeats/genetics , Alleles
9.
Nat Chem Biol ; 15(12): 1241-1248, 2019 12.
Article in English | MEDLINE | ID: mdl-31611704

ABSTRACT

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.


Subject(s)
Chloroplasts/metabolism , Holliday Junction Resolvases/metabolism , Plant Proteins/metabolism , Holliday Junction Resolvases/chemistry , Molecular Dynamics Simulation , Protein Conformation , Substrate Specificity
10.
Microb Cell Fact ; 20(1): 11, 2021 Jan 09.
Article in English | MEDLINE | ID: mdl-33422055

ABSTRACT

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.


Subject(s)
Amino Acid Oxidoreductases/metabolism , Amino Acids/metabolism , Aminohydrolases/metabolism , Formate Dehydrogenases/metabolism , Biocatalysis , Burkholderia/enzymology , Clostridiales/enzymology , Proteus mirabilis/enzymology , Stereoisomerism , Substrate Specificity
11.
Biochem Biophys Res Commun ; 523(1): 66-71, 2020 02 26.
Article in English | MEDLINE | ID: mdl-31831172

ABSTRACT

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.


Subject(s)
Medicago truncatula/metabolism , Peptides/metabolism , Plant Proteins/metabolism , Transcription Factors/metabolism , Medicago truncatula/genetics , Peptides/genetics , Plant Proteins/genetics , Plant Root Nodulation/genetics , Plant Roots/metabolism , Sinorhizobium meliloti/metabolism , Transcription Factors/genetics
13.
Sensors (Basel) ; 20(18)2020 Sep 17.
Article in English | MEDLINE | ID: mdl-32957619

ABSTRACT

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.

14.
BMC Biotechnol ; 18(1): 25, 2018 05 04.
Article in English | MEDLINE | ID: mdl-29728076

ABSTRACT

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.


Subject(s)
Antibodies, Monoclonal/biosynthesis , Chromogranin A/immunology , Neoplasms/diagnosis , Animals , Antibodies, Monoclonal/genetics , Antibody Specificity , Humans , Immunohistochemistry , Mice, Inbred BALB C
15.
Bioorg Med Chem ; 24(22): 6040-6047, 2016 11 15.
Article in English | MEDLINE | ID: mdl-27713013

ABSTRACT

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.


Subject(s)
Antineoplastic Agents/pharmacology , Photochemotherapy , Porphyrins/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Female , HeLa Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Molecular Structure , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/pathology , Photochemical Processes , Porphyrins/chemical synthesis , Porphyrins/chemistry , Structure-Activity Relationship
16.
Bioprocess Biosyst Eng ; 39(4): 533-43, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26753831

ABSTRACT

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.


Subject(s)
Ethanol/chemistry , Glucose/chemistry , Glycerol/chemistry , Juglans/chemistry , Perchlorates/chemistry , Sodium Hydroxide/chemistry , Lignin/chemistry , Polysaccharides/chemistry , Water/chemistry
17.
Biotechnol Lett ; 37(1): 183-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25214230

ABSTRACT

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.


Subject(s)
Propylene Glycols/metabolism , Rhodococcus/metabolism , Sulfates/metabolism , Bacterial Proteins/metabolism , Biotechnology , Biotransformation , Cells, Immobilized , Hydrogen-Ion Concentration , Propylene Glycols/analysis , Rhodococcus/enzymology , Sulfatases/metabolism , Sulfates/analysis
18.
Nat Commun ; 15(1): 5140, 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38886375

ABSTRACT

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.


Subject(s)
DNA, Cruciform , DNA, Cruciform/metabolism , DNA, Cruciform/chemistry , DNA, Cruciform/genetics , Metals/metabolism , Metals/chemistry , Holliday Junction Resolvases/metabolism , Holliday Junction Resolvases/chemistry , Catalytic Domain , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/genetics , Crystallography, X-Ray , Ions/metabolism , DNA Breaks, Double-Stranded , Models, Molecular , Allosteric Regulation
19.
Bioresour Technol ; 399: 130579, 2024 May.
Article in English | MEDLINE | ID: mdl-38479628

ABSTRACT

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.


Subject(s)
Ferric Compounds , Lignin , Lignin/chemistry , Chlorides , Zea mays/chemistry , Deep Eutectic Solvents , Solvents/chemistry , Biomass , Cellulose/chemistry , Xylans , Hydrolysis
20.
Poult Sci ; 103(2): 103271, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38064882

ABSTRACT

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.


Subject(s)
Herpesviridae Infections , Herpesvirus 1, Gallid , Poultry Diseases , Viral Vaccines , Chick Embryo , Animals , Chickens , Herpesvirus 1, Gallid/genetics , Virulence , Phylogeny , Ovum , Herpesviridae Infections/epidemiology , Herpesviridae Infections/veterinary , Poultry Diseases/prevention & control
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