In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic...In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.展开更多
A series of novel pyrazole fused heterocyclic derivatives were synthesized via a two-step procedure or a one-pot two step method, and their catalytic DNA cleavage abilities and anti-BVDV activities were also evaluated...A series of novel pyrazole fused heterocyclic derivatives were synthesized via a two-step procedure or a one-pot two step method, and their catalytic DNA cleavage abilities and anti-BVDV activities were also evaluated. The results obtained indicated that compounds 3b-3c could catalyze the cleavage of supercoiled DNA (pUC 19 plasmid DNA) to nicked DNA under physiological conditions with high yields via a hydrolytic mechanism. The studies on anti-viral activities against bovine viral diarrhea virus (BVDV) demonstrated that some of the pyrazole derivatives showed pronounced anti-BVDV activity with interesting ECso values and no significant cytotoxicity. Among them, compound 31 showed the highest antiviral activity (ECso = 0.12 μmol/L) and was 10 fold more than that of the positive control ribavirin (ECso = 1.3 μmol/L), which provided a potential candidate for the development of anti-BVDV agents.展开更多
Renewable electrocatalytic upgrading of biomass feedstocks into valuable chemicals is one of the promising strategies to relieve the pressure of traditional energy-based systems.Through electrocatalytic carbon–carbon...Renewable electrocatalytic upgrading of biomass feedstocks into valuable chemicals is one of the promising strategies to relieve the pressure of traditional energy-based systems.Through electrocatalytic carbon–carbon bond cleavage of high selectivity,various functionalized molecules,such as organic acids,amides,esters,and nitriles,have great potential to be accessed from biomass.However,it has merely received finite concerns and interests in the biorefinery.This review first showcases the research progress on the electrocatalytic conversion of lipid/sugar-and lignin-derived molecules(e.g.,glycerol,mesoerythritol,xylose,glucose,1-phenylethanol,and cyclohexanol)into organic acids via specific carbon–carbon bond scission processes,with focus on disclosing reaction mechanisms,recognizing actual active species,and collecting feasible modification strategies.For the guidance of further extensive studies on biomass valorization,organic transformations via a variety of reactions,including decarboxylation,ring-opening,rearrangement,reductive hydrogenation,and carboxylation,are also disclosed for the construction of similar carbon skeletons/scaffolds.The remaining challenges,prospective applications,and future objectives in terms of biomass conversion are also proposed.This review is expected to provide references to develop renewed electrocatalytic carbon–carbon bond cleavage transformation paths/strategies for biomass upgrading.展开更多
Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the ...Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.展开更多
Pentatricopeptide repeat(PPR)proteins represent one of the largest protein families in plants and typically localize to organelles like mitochondria and chloroplasts.By contrast,CYTOPLASMLOCALIZED PPR1(OsCPPR1)is a cy...Pentatricopeptide repeat(PPR)proteins represent one of the largest protein families in plants and typically localize to organelles like mitochondria and chloroplasts.By contrast,CYTOPLASMLOCALIZED PPR1(OsCPPR1)is a cytoplasm-localized PPR protein that can degrade OsGOLDENLIKE1(OsGLK1)mRNA in the tapetum of rice anther.However,the mechanism,by which OsCPPR1 recognizes and binds to OsGLK1 transcripts,remains unknown.Through protein structure prediction and macromolecular docking experiments,we observed that distinct PPR motif structures of OsCPPR1 exhibited varying binding efficiencies to OsGLK1 RNA.Moreover,RNA-electrophoretic mobility shift assay experiment demonstrated that the recombinant OsCPPR1 can directly recognize and bind to OsGLK1 mRNA in vitro.This further confirmed that the mutations in the conserved amino acids in each PPR motif resulted in loss of activity,while truncation of OsCPPR1 decreased its binding efficiency.These findings collectively suggest that it may require some co-factors to assist in cleavage,a facet that warrants further exploration in subsequent studies.展开更多
BACKGROUND The intricate relationship between type 2 diabetes mellitus(T2DM)and diabetic nephropathy(DN)presents a challenge in understanding the significance of various biomarkers in diagnosis.AIM To elucidate the ro...BACKGROUND The intricate relationship between type 2 diabetes mellitus(T2DM)and diabetic nephropathy(DN)presents a challenge in understanding the significance of various biomarkers in diagnosis.AIM To elucidate the roles and diagnostic values ofα2-macroglobulin(α2-MG),podocalyxin(PCX),α-L-fucosidase(AFU),retinol-binding protein-4(RBP-4),and cystatin C(CysC)in DN.METHODS From December 2018 to December 2020,203 T2DM patients were enrolled in the study.Of these,115 were diagnosed with DN(115 patients),while the remaining 88 patients were classified as non-DN.The urinary levels ofα2-MG,PCX,and AFU and the serum concentrations RBP-4 and CysC were measured in conjunction with other relevant clinical indicators to evaluate their potential correlations and diagnostic utility.RESULTS After adjustments for age and gender,significant positive correlations were observed between the biomarkers CysC,RBP-4,α2-MG/urinary creatinine(UCr),PCX/UCr,and AFU/UCr,and clinical indicators such as urinary albumin-to-creatinine ratio(UACR),serum creatinine,urea,24-h total urine protein,and neutrophil-to-lymphocyte ratio(NLR).Conversely,these biomarkers exhibited negative correlations with the estimated glomerular filtration rate(P<0.05).Receiver operating characteristic(ROC)curve analysis further demonstrated the diagnostic performance of these biomarkers,with UACR showcasing the highest area under the ROC curve(AUC^(ROC))at 0.97.CONCLUSION This study underscores the diagnostic significance ofα2-MG,PCX,and AFU in the development of DN.The biomarkers RBP-4,CysC,PCX,AFU,andα2-MG provide promising diagnostic insights,while UACR is the most potent diagnostic biomarker in assessing DN.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is an aggressive subtype of liver cancer and is one of the most common cancers with high mortality worldwide.Reprogrammed lipid metabolism plays crucial roles in HCC cancer cell...BACKGROUND Hepatocellular carcinoma(HCC)is an aggressive subtype of liver cancer and is one of the most common cancers with high mortality worldwide.Reprogrammed lipid metabolism plays crucial roles in HCC cancer cell survival,growth,and evolution.Emerging evidence suggests the importance of fatty acid binding proteins(FABPs)in contribution to cancer progression and metastasis;however,how these FABPs are dysregulated in cancer cells,especially in HCC,and the roles of FABPs in cancer progression have not been well defined.AIM To understand the genetic alterations and expression of FABPs and their associated cancer hallmarks and oncogenes in contributing to cancer malignancies.METHODS We used The Cancer Genome Atlas datasets of pan cancer and liver hepatocellular carcinoma(LIHC)as well as patient cohorts with other cancer types in this study.We investigated genetic alterations of FABPs in various cancer types.mRNA expression was used to determine if FABPs are abnormally expressed in tumor tissues compared to non-tumor controls and to investigate whether their expression correlates with patient clinical outcome,enriched cancer hallmarks and oncogenes previously reported for patients with HCC.We determined the protein levels of FABP5 and its correlated genes in two HCC cell lines and assessed the potential of FABP5 inhibition in treating HCC cells.RESULTS We discovered that a gene cluster including five FABP family members(FABP4,FABP5,FABP8,FABP9 and FABP12)is frequently co-amplified in cancer.Amplification,in fact,is the most common genetic alteration for FABPs,leading to overexpression of FABPs.FABP5 showed the greatest differential mRNA expression comparing tumor with non-tumor tissues.High FABP5 expression correlates well with worse patient outcomes(P<0.05).FABP5 expression highly correlates with enrichment of G2M checkpoint(r=0.33,P=1.1e-10),TP53 signaling pathway(r=0.22,P=1.7e-5)and many genes in the gene sets such as CDK1(r=0.56,P=0),CDK4(r=0.49,P=0),and TP53(r=0.22,P=1.6e-5).Furthermore,FABP5 also correlates well with two co-expressed oncogenes PLK1 and BIRC5 in pan cancer especially in LIHC patients(r=0.58,P=0;r=0.58,P=0;respectively).FABP5high Huh7 cells also expressed higher protein levels of p53,BIRC5,CDK1,CDK2,and CDK4 than FABP5low HepG2 cells.FABP5 inhibition more potently inhibited the tumor cell growth in Huh7 cells than in HepG2 cells.CONCLUSION We discovered that FABP5 gene is frequently amplified in cancer,especially in HCC,leading to its significant elevated expression in HCC.Its high expression correlates well with worse patient outcome,enriched cancer hallmarks and oncogenes in HCC.FABP5 inhibition impaired the cell viability of FABP5high Huh7 cells.All these support that FABP5 is a novel therapeutic target for treating FABP5high HCC.展开更多
BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untran...BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untranslated region(UTR)point mutations in ankyrin repeat domain containing 26(ANKRD26).Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1)have been identified as negative regulators of ANKRD26.However,the positive regulators of ANKRD26 are still unknown.AIM To prove the positive regulatory effect of GATA binding protein 2(GATA2)on ANKRD26 transcription.METHODS Human induced pluripotent stem cells derived from bone marrow(hiPSC-BM)INTRODUCTION Ankyrin repeat domain containing protein 26(ANKRD26)acts as a regulator of adipogenesis and is involved in the regulation of feeding behavior[1-3].The ANKRD26 gene is located on chromosome 10 and shares regions of homology with the primate-specific gene family POTE.According to the Human Protein Atlas database,the ANKRD26 protein is localized to the Golgi apparatus and vesicles,and its expression can be detected in nearly all human tissues[4].Moreover,UniProt annotation revealed that ANKRD26 is localized in the centrosome and contains coiled-coil domains formed by spectrin helices and ankyrin repeats[5,6].The most common disease related to ANKRD26 is thrombocytopenia 2(THC2),which is a rare autosomal dominant inherited disease characterized by lifelong mild-to-moderate thrombocytopenia and mild bleeding[7-9].Caused by the variants in the 5’-untranslated region(UTR)of ANKRD26,THC2 is defined by a decrease in the number of platelets in circulating blood and results in increased bleeding and decreased clotting ability[8,10].Due to the point mutations that occur in the 5’-UTR of ANKRD26,its negative transcription factors(TFs),Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1),lose their repression effect[11].The persistent expression of ANKRD26 increases the activity of the mitogen activated protein kinase and extracellular signal regulated kinase 1/2 signaling pathways,which are potentially involved in the regulation of thrombopoietin-dependent signaling and further impair proplatelet formation by megakaryocytes(MKs)[11].However,the positive regulators of ANKRD26,which might be associated with THC2 pathology,are still unknown.展开更多
Hydrophobic Val derivative Schiff base copper(II) complexes and dipeptide (AlaAla, GlyGly) derivative Schiff base copper(II) complexes were introduced into egg white lysozyme. X-ray crystal structure analysis revealed...Hydrophobic Val derivative Schiff base copper(II) complexes and dipeptide (AlaAla, GlyGly) derivative Schiff base copper(II) complexes were introduced into egg white lysozyme. X-ray crystal structure analysis revealed amino acid derivative Schiff base copper(II) complexes were obtained. Herein we discuss primarily on the binding mode of copper(II) of the complexes obtained with egg white lysozyme. The electron density of copper(II) ions was confirmed by X-ray crystal structure analysis. The Val derivative Schiff base copper(II) complex was weakly bound at Arg114 of egg white lysozyme. In other copper(II) complexes, binding of copper(II) ions with dissociated ligands to various residues was observed. The binding sites of copper(II) ions were compared with computational scientific predictions.展开更多
BACKGROUND Colorectal cancer(CRC)causes many deaths worldwide.Synaptotagmin binding cytoplasmic RNA interacting protein(SYNCRIP)is an RNA-binding protein that plays an important role in multiple cancers by epigenetica...BACKGROUND Colorectal cancer(CRC)causes many deaths worldwide.Synaptotagmin binding cytoplasmic RNA interacting protein(SYNCRIP)is an RNA-binding protein that plays an important role in multiple cancers by epigenetically targeting some genes.Our study will examine the expression,potential effect,biological function and clinical value of SYNCRIP in CRC.AIM To examine the expression,potential effect,biological function and clinical value METHODS The expression of SYNCRIP was examined by immunohistochemistry arrays and high-throughput data.The effect of SYNCRIP gene in CRC cell growth was evaluated by CRISPR-Cas9 technology.The target genes of SYNCRIP were calculated using various algorithms,and the molecular mechanism of SYNCRIP in CRC was explored by mutation analysis and pathway analysis.The clinical value of SYNCRIP in prognosis and radiotherapy was revealed via evidence-based medicine methods.RESULTS The protein and mRNA levels of SYNCRIP were both highly expressed in CRC samples compared to nontumorous tissue based on 330 immunohistochemistry arrays and 3640 CRC samples.Cells grew more slowly in eleven CRC cell lines after knocking out the SYNCRIP gene.SYNCRIP could epigenetically target genes to promote the occurrence and development of CRC by boosting the cell cycle and affecting the tumor microenvironment.In addition,CRC patients with high SYNCRIP expression are more sensitive to radiotherapy.CONCLUSION SYNCRIP is upregulated in CRC,and highly expressed SYNCRIP can accelerate CRC cell division by exerting its epigenetic regulatory effects.In addition,SYNCRIP is expected to become a potential biomarker to predict the effect of radiotherapy.展开更多
In this paper, we consider the relationship between the binding number and the existence of fractional k-factors of graphs. The binding number of G is defined by Woodall as bind(G)=min{ | NG(X) || X |:∅≠X⊆V(G) }. It ...In this paper, we consider the relationship between the binding number and the existence of fractional k-factors of graphs. The binding number of G is defined by Woodall as bind(G)=min{ | NG(X) || X |:∅≠X⊆V(G) }. It is proved that a graph G has a fractional 1-factor if bind(G)≥1and has a fractional k-factor if bind(G)≥k−1k. Furthermore, it is showed that both results are best possible in some sense.展开更多
The basis functions of the translation invariant shell model are used to construct the ground state nuclear wave functions of <sup>3</sup>H. The used residual two-body interactions consist of central, tens...The basis functions of the translation invariant shell model are used to construct the ground state nuclear wave functions of <sup>3</sup>H. The used residual two-body interactions consist of central, tensor, spin orbit and quadratic spin orbit terms with Gaussian radial dependence. The parameters of these interactions are so chosen in such a way that they represent the long-range attraction and the short-range repulsion of the nucleon-nucleon interactions. These parameters are so chosen to reproduce good agreement between the calculated values of the binding energy, the root mean-square radius, the D-state probability, the magnetic dipole moment and the electric quadrupole moment of the deuteron nucleus. The variation method is then used to calculate the binding energy of triton by varying the oscillator parameter which exists in the nuclear wave function. The obtained nuclear wave functions are then used to calculate the root mean-square radius and the magnetic dipole moment of the triton.展开更多
A copper-bispyridylpyrrolide complex [Cu(PDPH)Cl](PDPH = 2,5-bis(2′-pyridyl)pyrrole) was synthesized and characterized. The complex crystallizes in the orthorhombic system with space group Pccn, a = 0.9016(3) nm, b =...A copper-bispyridylpyrrolide complex [Cu(PDPH)Cl](PDPH = 2,5-bis(2′-pyridyl)pyrrole) was synthesized and characterized. The complex crystallizes in the orthorhombic system with space group Pccn, a = 0.9016(3) nm, b = 1.0931(4) nm, c =2.5319(8) nm, and V = 2.4951(15) nm3. The copper center is situated in a square planar geometry. The interaction of the copper(II)complex with calf thymus DNA(CT-DNA) was investigated by electronic absorption, circular dichroism(CD) and fluorescence spectra. It is proposed that the complex binds to CT-DNA through groove binding mode. Nuclease activity of the complex was also studied by gel electrophoresis method. The complex can efficiently cleave supercoiled p BR322 DNA in the presence of ascorbate(H2A) via oxidative pathway. The preliminary mechanism of DNA cleavage by the complex with different inhibiting reagents indicates that the hydroxyl radicals were involved as the active species in the DNA cleavage process.展开更多
A new dinuclear complex, [Ag(L)(CH3CN)]2(ClO4)2·2H2O(L=2,3-di-2-pyridylquinoxaline), was prepared and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction analyses. T...A new dinuclear complex, [Ag(L)(CH3CN)]2(ClO4)2·2H2O(L=2,3-di-2-pyridylquinoxaline), was prepared and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction analyses. The interaction of the complex with calf thymus DNA(CT-DNA) was investigated by absorption, fluorescence spectroscopies, and viscosity measurement. The results suggested that the complex was bound to DNA via an intercalative mode. The intrinsic binding constant value Kb was found to be approximately 1.48×10^3 L·mol^-1. Moreover, the Ag(I) complex could cleave the plasmid pUC19 DNA from the supercoiled Form Ⅰto the nicked FormⅡ under irradiation at 365 nm.展开更多
We reported the synthesis of a simple bifunctional molecule and the interaction between this molecule and DNA were studied by UV and the DNA cleavage behavoior was determined by agarose gel electrophoresis.
The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]^2+, where L is 2-[bis(2- aminoethyl)amino]ethanol, with oxidized insulin B chain are Phel, His5 and Arg22, which le...The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]^2+, where L is 2-[bis(2- aminoethyl)amino]ethanol, with oxidized insulin B chain are Phel, His5 and Arg22, which lead to the selective cleavages of the peptide bonds at Phe1-Val2, His5-Leu6, Glu21-Arg22, and Arg22-Gly23 of oxidized insulin B chain.展开更多
An unsymmetrical oxovanadium complex [VO(SAA)(phen) ](1),(SAA = salicylidene anthranilic acid,phen = phenanthroline) and its novel derivatives [VO(MOSAA)(phen) ](2)(MOSAA = 2-hydroxy-4-methoxysalicylidene anthranilic)...An unsymmetrical oxovanadium complex [VO(SAA)(phen) ](1),(SAA = salicylidene anthranilic acid,phen = phenanthroline) and its novel derivatives [VO(MOSAA)(phen) ](2)(MOSAA = 2-hydroxy-4-methoxysalicylidene anthranilic) have been synthesized and characterized by elemental analysis,UV-Vis,ES-MS,IR and 1 H NMR.The interaction of these two complexes with CT-DNA was investigated by absorption titration,fluorescence spectra,viscosity measurements and thermal denaturation.Their photocleavage reactions with pBR322 supercoiled plasmid DNA were investigated by gel electrophoresis experiments.The cytotoxicity of these two complexes against Myeloma cell(Ag8.653) and Gliomas cell(U251) have been assessed by MTT assay.The experimental results show that both complexes 1 and 2 bind to CT-DNA in classical intercalation mode,and the DNA-binding affinity of the complex 1 is larger than that of complex 2.It is interesting to note that these two complexes prominently enhance the oxidative cleavage of supercoiled pBR322 DNA and both complexes present cytotoxic activities against Ag8.653 and U251 cell lines.Complex 1 possessed the more potent inhibitory effect against the two cell lines of the two complexes.展开更多
Three mononuclear oxovanadium complexes [VO(Hbid)(CF3PIP)] (1) (Hbid=(E)-2-(2-hydroxybenzylideneamino) isoindoline-1,3-dione, CF3PIP=2-(2-trifluoromethyl phenyl)imidazole[4,5-f][1,10] phenanthroline), [VO(Hbid)(m-CF3P...Three mononuclear oxovanadium complexes [VO(Hbid)(CF3PIP)] (1) (Hbid=(E)-2-(2-hydroxybenzylideneamino) isoindoline-1,3-dione, CF3PIP=2-(2-trifluoromethyl phenyl)imidazole[4,5-f][1,10] phenanthroline), [VO(Hbid)(m-CF3PIP)];(2) (m-CF3PIP=2-(3-trifluoromethyl phenyl)imidazole [4, 5-f][1,10]phenanthroline) and [VO(Hbid)(p-CF3PIP)];(3) (p-CF3PIP=2-(4-trifluoromethyl phenyl) imidazole[4,5-f][1,10]phenanthroline) have been synthesized and characterized by elemental analysis, IR, molar conductance, ES-MS and 1H NMR. The DNA-binding properties of these complexes were studied by using UV-Vis absorption titration, fluorescence spectra, viscosity measurements and thermal denaturation studies. The results show that 1, 2 and 3 interact with calf thymus DNA (CT-DNA) by intercalation modes and the magnitude of their intrinsic binding constants (Kb values) follows the order: 2 < 1 < 3. Furthermore, their photocleavage properties with pBR322 plasmid DNA were investigated by agarose gel electrophoresis experiments. The DNA cleavage capacity of complex 3 is also stronger than that of 1 and 2.展开更多
The ability to navigate long distances is essential for many animals to locate shelter,food,and breeding grounds.Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnet...The ability to navigate long distances is essential for many animals to locate shelter,food,and breeding grounds.Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnetic field.A highly conserved ironsulfur cluster assembly protein IscA is proposed as an animal magnetoreceptor(MagR).Iron-sulfur cluster binding is also suggested to play an essential role in MagR magnetism and is thus critical in animal magnetoreception.In the current study,we provide evidence for distinct iron binding and iron-sulfur cluster binding in MagR in pigeons,an avian species that relies on the geomagnetic field for navigation and homing.Pigeon MagR showed significantly higher total iron content from both iron-and ironsulfur binding.Y65 in pigeon MagR was shown to directly mediate mononuclear iron binding,and its mutation abolished iron-binding capacity of the protein.Surprisingly,both iron binding and iron-sulfur binding demonstrated synergistic effects,and thus appear to be integral and indispensable to pigeon MagR magnetism.These results not only extend our current understanding of the origin and complexity of MagR magnetism,but also imply a possible molecular explanation for the huge diversity in animal magnetoreception.展开更多
Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutr...Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutrality in nature.Selective tailoring of α-O-4,β-O-4,etc.linkages in lignin has always been viewed as "death blow" for its depolymerization.Herein,novel sodium lignosulfonate(SL) modified Fe_(3)O_(4)/TiO_(2)(SL-Fe_(3)O_(4)/TiO_(2)) spherical particles have been developed and used as catalysts for selectively photocatalytic oxidative cleavage of organosolv lignin.As expected,80% selective conversion of lignin in C2-C4 esters has been achieved,while C-O bonds in lignin model compounds can be effectively cleaved.Other than normal hydroxyl radical-mediated photocatalytic depolymerization of lignin over TiO_(2)-based materials,in this contribution,mechanism studies indicate that photogenerated holes and superoxide anion radicals are main active species,which trigger the cleavage of α/β-O-4 bond,and the isotopelabeling study confirms the crucial factor of C_β-H dehydrogenation in cleavage of β-O-4 bonds.展开更多
基金The Guangdong Basic and Applied Basic Research Foundation(2022A1515010730)National Natural Science Foundation of China(32001647)+2 种基金National Natural Science Foundation of China(31972022)Financial and moral assistance supported by the Guangdong Basic and Applied Basic Research Foundation(2019A1515011996)111 Project(B17018)。
文摘In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.
基金the National Natural Science Foundation of China (Nos.21105091 and 20772113) for the financial support
文摘A series of novel pyrazole fused heterocyclic derivatives were synthesized via a two-step procedure or a one-pot two step method, and their catalytic DNA cleavage abilities and anti-BVDV activities were also evaluated. The results obtained indicated that compounds 3b-3c could catalyze the cleavage of supercoiled DNA (pUC 19 plasmid DNA) to nicked DNA under physiological conditions with high yields via a hydrolytic mechanism. The studies on anti-viral activities against bovine viral diarrhea virus (BVDV) demonstrated that some of the pyrazole derivatives showed pronounced anti-BVDV activity with interesting ECso values and no significant cytotoxicity. Among them, compound 31 showed the highest antiviral activity (ECso = 0.12 μmol/L) and was 10 fold more than that of the positive control ribavirin (ECso = 1.3 μmol/L), which provided a potential candidate for the development of anti-BVDV agents.
基金financially supported by the National Natural Science Foundation of China(22368014)the Guizhou Provincial S&T Project(ZK[2022]011,GCC[2023]011)+1 种基金the Guizhou Provincial Higher Education Institution Program(Qianjiaoji[2023]082)supported by RUDN University Strategic Academic Leadership Program。
文摘Renewable electrocatalytic upgrading of biomass feedstocks into valuable chemicals is one of the promising strategies to relieve the pressure of traditional energy-based systems.Through electrocatalytic carbon–carbon bond cleavage of high selectivity,various functionalized molecules,such as organic acids,amides,esters,and nitriles,have great potential to be accessed from biomass.However,it has merely received finite concerns and interests in the biorefinery.This review first showcases the research progress on the electrocatalytic conversion of lipid/sugar-and lignin-derived molecules(e.g.,glycerol,mesoerythritol,xylose,glucose,1-phenylethanol,and cyclohexanol)into organic acids via specific carbon–carbon bond scission processes,with focus on disclosing reaction mechanisms,recognizing actual active species,and collecting feasible modification strategies.For the guidance of further extensive studies on biomass valorization,organic transformations via a variety of reactions,including decarboxylation,ring-opening,rearrangement,reductive hydrogenation,and carboxylation,are also disclosed for the construction of similar carbon skeletons/scaffolds.The remaining challenges,prospective applications,and future objectives in terms of biomass conversion are also proposed.This review is expected to provide references to develop renewed electrocatalytic carbon–carbon bond cleavage transformation paths/strategies for biomass upgrading.
基金the National Key R&D Program of China(No.2023YFA1606503)the National Natural Science Foundation of China(Nos.12035011,11975167,11947211,11905103,11881240623,and 11961141003).
文摘Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.
基金the Open Competition Program of Top Ten Critical Priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province,China(Grant No.2022SDZG05)the National Natural Science Foundation of China(Grants Nos.32000457,31871231,and 31921004)+1 种基金the Major Program of Guangdong Basic and Applied Research,China(Grant No.2019B030302006)the Double First-Class Discipline Promotion Project,China(Grant No.2021B10564001).
文摘Pentatricopeptide repeat(PPR)proteins represent one of the largest protein families in plants and typically localize to organelles like mitochondria and chloroplasts.By contrast,CYTOPLASMLOCALIZED PPR1(OsCPPR1)is a cytoplasm-localized PPR protein that can degrade OsGOLDENLIKE1(OsGLK1)mRNA in the tapetum of rice anther.However,the mechanism,by which OsCPPR1 recognizes and binds to OsGLK1 transcripts,remains unknown.Through protein structure prediction and macromolecular docking experiments,we observed that distinct PPR motif structures of OsCPPR1 exhibited varying binding efficiencies to OsGLK1 RNA.Moreover,RNA-electrophoretic mobility shift assay experiment demonstrated that the recombinant OsCPPR1 can directly recognize and bind to OsGLK1 mRNA in vitro.This further confirmed that the mutations in the conserved amino acids in each PPR motif resulted in loss of activity,while truncation of OsCPPR1 decreased its binding efficiency.These findings collectively suggest that it may require some co-factors to assist in cleavage,a facet that warrants further exploration in subsequent studies.
基金pported by the Natural Science Foundation of Inner Mongolia Autonomous Region,No.2022MS08057.
文摘BACKGROUND The intricate relationship between type 2 diabetes mellitus(T2DM)and diabetic nephropathy(DN)presents a challenge in understanding the significance of various biomarkers in diagnosis.AIM To elucidate the roles and diagnostic values ofα2-macroglobulin(α2-MG),podocalyxin(PCX),α-L-fucosidase(AFU),retinol-binding protein-4(RBP-4),and cystatin C(CysC)in DN.METHODS From December 2018 to December 2020,203 T2DM patients were enrolled in the study.Of these,115 were diagnosed with DN(115 patients),while the remaining 88 patients were classified as non-DN.The urinary levels ofα2-MG,PCX,and AFU and the serum concentrations RBP-4 and CysC were measured in conjunction with other relevant clinical indicators to evaluate their potential correlations and diagnostic utility.RESULTS After adjustments for age and gender,significant positive correlations were observed between the biomarkers CysC,RBP-4,α2-MG/urinary creatinine(UCr),PCX/UCr,and AFU/UCr,and clinical indicators such as urinary albumin-to-creatinine ratio(UACR),serum creatinine,urea,24-h total urine protein,and neutrophil-to-lymphocyte ratio(NLR).Conversely,these biomarkers exhibited negative correlations with the estimated glomerular filtration rate(P<0.05).Receiver operating characteristic(ROC)curve analysis further demonstrated the diagnostic performance of these biomarkers,with UACR showcasing the highest area under the ROC curve(AUC^(ROC))at 0.97.CONCLUSION This study underscores the diagnostic significance ofα2-MG,PCX,and AFU in the development of DN.The biomarkers RBP-4,CysC,PCX,AFU,andα2-MG provide promising diagnostic insights,while UACR is the most potent diagnostic biomarker in assessing DN.
基金Tianjin Key Medical Discipline Construction Project,No.TJYXZDXK-034A.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is an aggressive subtype of liver cancer and is one of the most common cancers with high mortality worldwide.Reprogrammed lipid metabolism plays crucial roles in HCC cancer cell survival,growth,and evolution.Emerging evidence suggests the importance of fatty acid binding proteins(FABPs)in contribution to cancer progression and metastasis;however,how these FABPs are dysregulated in cancer cells,especially in HCC,and the roles of FABPs in cancer progression have not been well defined.AIM To understand the genetic alterations and expression of FABPs and their associated cancer hallmarks and oncogenes in contributing to cancer malignancies.METHODS We used The Cancer Genome Atlas datasets of pan cancer and liver hepatocellular carcinoma(LIHC)as well as patient cohorts with other cancer types in this study.We investigated genetic alterations of FABPs in various cancer types.mRNA expression was used to determine if FABPs are abnormally expressed in tumor tissues compared to non-tumor controls and to investigate whether their expression correlates with patient clinical outcome,enriched cancer hallmarks and oncogenes previously reported for patients with HCC.We determined the protein levels of FABP5 and its correlated genes in two HCC cell lines and assessed the potential of FABP5 inhibition in treating HCC cells.RESULTS We discovered that a gene cluster including five FABP family members(FABP4,FABP5,FABP8,FABP9 and FABP12)is frequently co-amplified in cancer.Amplification,in fact,is the most common genetic alteration for FABPs,leading to overexpression of FABPs.FABP5 showed the greatest differential mRNA expression comparing tumor with non-tumor tissues.High FABP5 expression correlates well with worse patient outcomes(P<0.05).FABP5 expression highly correlates with enrichment of G2M checkpoint(r=0.33,P=1.1e-10),TP53 signaling pathway(r=0.22,P=1.7e-5)and many genes in the gene sets such as CDK1(r=0.56,P=0),CDK4(r=0.49,P=0),and TP53(r=0.22,P=1.6e-5).Furthermore,FABP5 also correlates well with two co-expressed oncogenes PLK1 and BIRC5 in pan cancer especially in LIHC patients(r=0.58,P=0;r=0.58,P=0;respectively).FABP5high Huh7 cells also expressed higher protein levels of p53,BIRC5,CDK1,CDK2,and CDK4 than FABP5low HepG2 cells.FABP5 inhibition more potently inhibited the tumor cell growth in Huh7 cells than in HepG2 cells.CONCLUSION We discovered that FABP5 gene is frequently amplified in cancer,especially in HCC,leading to its significant elevated expression in HCC.Its high expression correlates well with worse patient outcome,enriched cancer hallmarks and oncogenes in HCC.FABP5 inhibition impaired the cell viability of FABP5high Huh7 cells.All these support that FABP5 is a novel therapeutic target for treating FABP5high HCC.
基金Supported by General Program of National Natural Science Foundation of China,No.81770197Scientific and Technological Research Major Program of Chongqing Municipal Education Commission,No.KJZD-M202312802+1 种基金Chongqing Natural Science Foundation of China,No.CSTB2022NSCQ-MSX0190,No.CSTB2022NSCQ-MSX0176,and No.cstc2020jcyj-msxmX0051Xinqiao Young Postdoc Talent Incubation Program,No.2022YQB098.
文摘BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untranslated region(UTR)point mutations in ankyrin repeat domain containing 26(ANKRD26).Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1)have been identified as negative regulators of ANKRD26.However,the positive regulators of ANKRD26 are still unknown.AIM To prove the positive regulatory effect of GATA binding protein 2(GATA2)on ANKRD26 transcription.METHODS Human induced pluripotent stem cells derived from bone marrow(hiPSC-BM)INTRODUCTION Ankyrin repeat domain containing protein 26(ANKRD26)acts as a regulator of adipogenesis and is involved in the regulation of feeding behavior[1-3].The ANKRD26 gene is located on chromosome 10 and shares regions of homology with the primate-specific gene family POTE.According to the Human Protein Atlas database,the ANKRD26 protein is localized to the Golgi apparatus and vesicles,and its expression can be detected in nearly all human tissues[4].Moreover,UniProt annotation revealed that ANKRD26 is localized in the centrosome and contains coiled-coil domains formed by spectrin helices and ankyrin repeats[5,6].The most common disease related to ANKRD26 is thrombocytopenia 2(THC2),which is a rare autosomal dominant inherited disease characterized by lifelong mild-to-moderate thrombocytopenia and mild bleeding[7-9].Caused by the variants in the 5’-untranslated region(UTR)of ANKRD26,THC2 is defined by a decrease in the number of platelets in circulating blood and results in increased bleeding and decreased clotting ability[8,10].Due to the point mutations that occur in the 5’-UTR of ANKRD26,its negative transcription factors(TFs),Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1),lose their repression effect[11].The persistent expression of ANKRD26 increases the activity of the mitogen activated protein kinase and extracellular signal regulated kinase 1/2 signaling pathways,which are potentially involved in the regulation of thrombopoietin-dependent signaling and further impair proplatelet formation by megakaryocytes(MKs)[11].However,the positive regulators of ANKRD26,which might be associated with THC2 pathology,are still unknown.
文摘Hydrophobic Val derivative Schiff base copper(II) complexes and dipeptide (AlaAla, GlyGly) derivative Schiff base copper(II) complexes were introduced into egg white lysozyme. X-ray crystal structure analysis revealed amino acid derivative Schiff base copper(II) complexes were obtained. Herein we discuss primarily on the binding mode of copper(II) of the complexes obtained with egg white lysozyme. The electron density of copper(II) ions was confirmed by X-ray crystal structure analysis. The Val derivative Schiff base copper(II) complex was weakly bound at Arg114 of egg white lysozyme. In other copper(II) complexes, binding of copper(II) ions with dissociated ligands to various residues was observed. The binding sites of copper(II) ions were compared with computational scientific predictions.
基金Supported by Guangxi Zhuang Autonomous Region Health Commission Scientific Research Project,No.Z-A20220415 and No.Z20210442The First Affiliated Hospital of Guangxi Medical University Provincial and Ministerial Key Laboratory Cultivation Project:Guangxi Laboratory of Enhanced Recovery after Surgery for Gastrointestinal Cancer,No.21-220-18.
文摘BACKGROUND Colorectal cancer(CRC)causes many deaths worldwide.Synaptotagmin binding cytoplasmic RNA interacting protein(SYNCRIP)is an RNA-binding protein that plays an important role in multiple cancers by epigenetically targeting some genes.Our study will examine the expression,potential effect,biological function and clinical value of SYNCRIP in CRC.AIM To examine the expression,potential effect,biological function and clinical value METHODS The expression of SYNCRIP was examined by immunohistochemistry arrays and high-throughput data.The effect of SYNCRIP gene in CRC cell growth was evaluated by CRISPR-Cas9 technology.The target genes of SYNCRIP were calculated using various algorithms,and the molecular mechanism of SYNCRIP in CRC was explored by mutation analysis and pathway analysis.The clinical value of SYNCRIP in prognosis and radiotherapy was revealed via evidence-based medicine methods.RESULTS The protein and mRNA levels of SYNCRIP were both highly expressed in CRC samples compared to nontumorous tissue based on 330 immunohistochemistry arrays and 3640 CRC samples.Cells grew more slowly in eleven CRC cell lines after knocking out the SYNCRIP gene.SYNCRIP could epigenetically target genes to promote the occurrence and development of CRC by boosting the cell cycle and affecting the tumor microenvironment.In addition,CRC patients with high SYNCRIP expression are more sensitive to radiotherapy.CONCLUSION SYNCRIP is upregulated in CRC,and highly expressed SYNCRIP can accelerate CRC cell division by exerting its epigenetic regulatory effects.In addition,SYNCRIP is expected to become a potential biomarker to predict the effect of radiotherapy.
文摘In this paper, we consider the relationship between the binding number and the existence of fractional k-factors of graphs. The binding number of G is defined by Woodall as bind(G)=min{ | NG(X) || X |:∅≠X⊆V(G) }. It is proved that a graph G has a fractional 1-factor if bind(G)≥1and has a fractional k-factor if bind(G)≥k−1k. Furthermore, it is showed that both results are best possible in some sense.
文摘The basis functions of the translation invariant shell model are used to construct the ground state nuclear wave functions of <sup>3</sup>H. The used residual two-body interactions consist of central, tensor, spin orbit and quadratic spin orbit terms with Gaussian radial dependence. The parameters of these interactions are so chosen in such a way that they represent the long-range attraction and the short-range repulsion of the nucleon-nucleon interactions. These parameters are so chosen to reproduce good agreement between the calculated values of the binding energy, the root mean-square radius, the D-state probability, the magnetic dipole moment and the electric quadrupole moment of the deuteron nucleus. The variation method is then used to calculate the binding energy of triton by varying the oscillator parameter which exists in the nuclear wave function. The obtained nuclear wave functions are then used to calculate the root mean-square radius and the magnetic dipole moment of the triton.
基金Project(21001118)supported by National Natural Science Foundation of ChinaProject(12JJ3016)supported by Natural Science Foundation of Hunan Province,China
文摘A copper-bispyridylpyrrolide complex [Cu(PDPH)Cl](PDPH = 2,5-bis(2′-pyridyl)pyrrole) was synthesized and characterized. The complex crystallizes in the orthorhombic system with space group Pccn, a = 0.9016(3) nm, b = 1.0931(4) nm, c =2.5319(8) nm, and V = 2.4951(15) nm3. The copper center is situated in a square planar geometry. The interaction of the copper(II)complex with calf thymus DNA(CT-DNA) was investigated by electronic absorption, circular dichroism(CD) and fluorescence spectra. It is proposed that the complex binds to CT-DNA through groove binding mode. Nuclease activity of the complex was also studied by gel electrophoresis method. The complex can efficiently cleave supercoiled p BR322 DNA in the presence of ascorbate(H2A) via oxidative pathway. The preliminary mechanism of DNA cleavage by the complex with different inhibiting reagents indicates that the hydroxyl radicals were involved as the active species in the DNA cleavage process.
基金Natural Science Foundation of Liaoning Province, China(No.20061073)Education Committee Foundation of Liaoning Province, China(No.22004F023)
文摘A new dinuclear complex, [Ag(L)(CH3CN)]2(ClO4)2·2H2O(L=2,3-di-2-pyridylquinoxaline), was prepared and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction analyses. The interaction of the complex with calf thymus DNA(CT-DNA) was investigated by absorption, fluorescence spectroscopies, and viscosity measurement. The results suggested that the complex was bound to DNA via an intercalative mode. The intrinsic binding constant value Kb was found to be approximately 1.48×10^3 L·mol^-1. Moreover, the Ag(I) complex could cleave the plasmid pUC19 DNA from the supercoiled Form Ⅰto the nicked FormⅡ under irradiation at 365 nm.
基金support from the National Natural Science Foundation of China(No.20132020)the National Science and Technology Committee of China,Chinese National Ministry of Education and Tsinghua University
文摘We reported the synthesis of a simple bifunctional molecule and the interaction between this molecule and DNA were studied by UV and the DNA cleavage behavoior was determined by agarose gel electrophoresis.
文摘The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]^2+, where L is 2-[bis(2- aminoethyl)amino]ethanol, with oxidized insulin B chain are Phel, His5 and Arg22, which lead to the selective cleavages of the peptide bonds at Phe1-Val2, His5-Leu6, Glu21-Arg22, and Arg22-Gly23 of oxidized insulin B chain.
文摘An unsymmetrical oxovanadium complex [VO(SAA)(phen) ](1),(SAA = salicylidene anthranilic acid,phen = phenanthroline) and its novel derivatives [VO(MOSAA)(phen) ](2)(MOSAA = 2-hydroxy-4-methoxysalicylidene anthranilic) have been synthesized and characterized by elemental analysis,UV-Vis,ES-MS,IR and 1 H NMR.The interaction of these two complexes with CT-DNA was investigated by absorption titration,fluorescence spectra,viscosity measurements and thermal denaturation.Their photocleavage reactions with pBR322 supercoiled plasmid DNA were investigated by gel electrophoresis experiments.The cytotoxicity of these two complexes against Myeloma cell(Ag8.653) and Gliomas cell(U251) have been assessed by MTT assay.The experimental results show that both complexes 1 and 2 bind to CT-DNA in classical intercalation mode,and the DNA-binding affinity of the complex 1 is larger than that of complex 2.It is interesting to note that these two complexes prominently enhance the oxidative cleavage of supercoiled pBR322 DNA and both complexes present cytotoxic activities against Ag8.653 and U251 cell lines.Complex 1 possessed the more potent inhibitory effect against the two cell lines of the two complexes.
文摘Three mononuclear oxovanadium complexes [VO(Hbid)(CF3PIP)] (1) (Hbid=(E)-2-(2-hydroxybenzylideneamino) isoindoline-1,3-dione, CF3PIP=2-(2-trifluoromethyl phenyl)imidazole[4,5-f][1,10] phenanthroline), [VO(Hbid)(m-CF3PIP)];(2) (m-CF3PIP=2-(3-trifluoromethyl phenyl)imidazole [4, 5-f][1,10]phenanthroline) and [VO(Hbid)(p-CF3PIP)];(3) (p-CF3PIP=2-(4-trifluoromethyl phenyl) imidazole[4,5-f][1,10]phenanthroline) have been synthesized and characterized by elemental analysis, IR, molar conductance, ES-MS and 1H NMR. The DNA-binding properties of these complexes were studied by using UV-Vis absorption titration, fluorescence spectra, viscosity measurements and thermal denaturation studies. The results show that 1, 2 and 3 interact with calf thymus DNA (CT-DNA) by intercalation modes and the magnitude of their intrinsic binding constants (Kb values) follows the order: 2 < 1 < 3. Furthermore, their photocleavage properties with pBR322 plasmid DNA were investigated by agarose gel electrophoresis experiments. The DNA cleavage capacity of complex 3 is also stronger than that of 1 and 2.
基金supported by the National Natural Science Foundation of China(31640001 to C.X.,U21A20148 to X.Z.and C.X.)the Presidential Foundation of Hefei Institutes of Physical Science,Chinese Academy of Sciences(Y96XC11131,E26CCG27,and E26CCD15 to C.X.)。
文摘The ability to navigate long distances is essential for many animals to locate shelter,food,and breeding grounds.Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnetic field.A highly conserved ironsulfur cluster assembly protein IscA is proposed as an animal magnetoreceptor(MagR).Iron-sulfur cluster binding is also suggested to play an essential role in MagR magnetism and is thus critical in animal magnetoreception.In the current study,we provide evidence for distinct iron binding and iron-sulfur cluster binding in MagR in pigeons,an avian species that relies on the geomagnetic field for navigation and homing.Pigeon MagR showed significantly higher total iron content from both iron-and ironsulfur binding.Y65 in pigeon MagR was shown to directly mediate mononuclear iron binding,and its mutation abolished iron-binding capacity of the protein.Surprisingly,both iron binding and iron-sulfur binding demonstrated synergistic effects,and thus appear to be integral and indispensable to pigeon MagR magnetism.These results not only extend our current understanding of the origin and complexity of MagR magnetism,but also imply a possible molecular explanation for the huge diversity in animal magnetoreception.
基金the financial support of the Natural Science Foundation of China (21736003, 22178130 and 22005106)the Natural Science Foundation of Guangdong Province, China (2020A0505100008)the Science and Technology Program of Guangzhou (202206010024)。
文摘Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutrality in nature.Selective tailoring of α-O-4,β-O-4,etc.linkages in lignin has always been viewed as "death blow" for its depolymerization.Herein,novel sodium lignosulfonate(SL) modified Fe_(3)O_(4)/TiO_(2)(SL-Fe_(3)O_(4)/TiO_(2)) spherical particles have been developed and used as catalysts for selectively photocatalytic oxidative cleavage of organosolv lignin.As expected,80% selective conversion of lignin in C2-C4 esters has been achieved,while C-O bonds in lignin model compounds can be effectively cleaved.Other than normal hydroxyl radical-mediated photocatalytic depolymerization of lignin over TiO_(2)-based materials,in this contribution,mechanism studies indicate that photogenerated holes and superoxide anion radicals are main active species,which trigger the cleavage of α/β-O-4 bond,and the isotopelabeling study confirms the crucial factor of C_β-H dehydrogenation in cleavage of β-O-4 bonds.