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Analysis of the electron transfer pathway in small laccase by EPR and UV-vis spectroscopy coupled with redox titration

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Magnetic Resonance Letters 2024年第3期4卷 52-59页

作者： Lu Yu Aokun Liu Jian Kuang Ruotong wei Zhiwen Wang Changlin Tian high Magnetic Field Laboratory Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei230031China Department of Endocrinology Institute of Endocrine and Metabolic DiseaseThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineHefei National Research Center for Physical Sciences at the MicroscaleJoint Center for Biological Analytical ChemistryAnhui Engineering Laboratory of Peptide DrugAnhui Laboratory of Advanced Photonic Science and TechnologyUniversity of Science and Technology of ChinaHefei230026China

Bacterial small laccases(SLAC) are promising industrial biocatalysts due to their ability to oxidize a broad range of substrates with exceptional thermostability and tolerance for alkaline p h. Electron transfer between substrate, copper centers, and O2is one of the key steps in the catalytic turnover of SLAC. however, limited research has been conducted on the electron transfer pathway of SLAC and SLAC-catalyzed reactions, hindering further engineering of SLAC to produce tunable biocatalysts for novel applications. herein, the combinational use of electron paramagnetic resonance(EPR) and ultraviolet-visible(UV-vis) spectroscopic methods coupled with redox titration were employed to monitor the electron transfer processes and obtain further insights into the electron transfer pathway in SLAC. The reduction potentials for type 1 copper(T1Cu), type 2 copper(T2Cu) and type 3copper(T3Cu) were determined to be 367 ± 2 mV, 378 ± 5 m V and 403 ± 2 mV,respectively. Moreover, the reduction potential of a selected substrate of SLAC, hydroquinone(hQ), was determined to be 288 mV using cyclic voltammetry(CV). In this way, an electron transfer pathway was identified based on the reduction potentials. Specifically,electrons are transferred from hQ to T1Cu, then to T2Cu and T3Cu, and finally to ***, superhyperfine splitting observed via EPR during redox titration indicated a modification in the covalency of T2Cu upon electron uptake, suggesting a conformational alteration in the protein environment surrounding the copper sites, which could potentially influence the reduction potential of the copper sites during catalytic processes. The results presented here not only provide a comprehensive method for analyzing the electron transfer pathway in metalloenzymes through reduction potential measurements, but also offer valuable insights for further engineering and directed evolution studies of SLAC in the aim for biotechnological and industrial applications.

关键词： Electron paramagnetic resonance Redox titration Electron transfer Reduction Potential Small laccase

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Virus-host Interactions Drive Contrasting Bacterial Diel Dynamics in the Ocean

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Research 2024年第2期6卷 389-399页

作者： xiaowei Chen Chen hu wei wei Yunlan Yang Markus G.weinbauer hongbo Li Shiying Ren Ruije Ma YVibin huang Tingwei Luo Nianzhi Jiao Rui Zhang State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesFujian Key Laboratory of Marine Carbon SequestrationXiamen UniversityXiamen 361102PR China College of the Environment and Ecology Xiamen UniversityXiamen 361102PR China Research Center for Environmental Ecology and Engineering School of Environmental Ecology and Biological EngineeringWuhan Institute of TechnologyWuhan 430205PR China Sorbonne Universités UPMCUniversitéParis 06CNRSLaboratoire d'Oceanographie de Villefranche(LOV)Villefranche-sur-Mer 06230France National Marine Environmental Monitoring Center Ministry of Ecological EnvironmentDalian 116023PR China Department of Ocean Sciences University of CaliforniaSanta CruzCAUSA NOAA/OAR Pacific Marine Environmental Laboratory SeattleWAUSA Institute for Advanced Study Shenzhen UniversityShenzhen 518055PR China

Marine organisms perform a sea of diel *** diel dynamics have been shown to be driven by light,energy resources,circadian rhythms,and the coordinated coupling of photoautotrophs and heterotrophic ***,we explore the diel fluctuation of viral production and decay and their impact on the total and active bacterial community in the coastal and open seawaters of the South China *** results showed that the night-production diel pattern of lytic viral production was concurrent with the lower viral decay at night,contributing to the accumulation of the viral population size during the night for surface *** diel variations in bacterial activity,community composition,and diversity were found highly affected by viral *** was revealed by the finding that bacterial community diversity was positively correlated to lytic viral production in the euphotic zone of the open ocean but was negatively related to lysogenic viral production in the coastal *** distinct but contrasting correlations suggest that viral life strategies can not only contribute to diversifying bacterial community but also potentially piggyback their host to dominate bacterial community,suggesting the tightly synchronized depth-dependent and habitat-specific diel patterns of virus-host *** further implies that viruses serve as an ecologically important driver of bacterial diel dynamics across the ocean,highlighting the viral roles in bacterial ecological and biogeochemical processes in the ocean.

关键词： coastal ocean Marine

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Ambient electrocatalytic synthesis of urea by co-reduction of NO_(3)^(-) and CO_(2) over graphene-supported In_(2)O_(3)

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Chinese Chemical Letters 2024年第3期35卷 538-543页

作者： Yini Mao Yong Jiang hao Liu Yimin Jiang Ming Li wei Su Rongxing he Key Laboratory of Luminescence Analysis and Molecular Sensing(Southwest University) Ministry of EducationCollege of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China Key Laboratory of Beibu Gulf Environment Change and Resources Utilization(Nanning Normal University) Ministry of EducationCollege of Chemistry and Life ScienceNanning Normal UniversityNanning 530000China

Urea plays a vital role in the sustainable development of mankind as it is one of the most important nitrogen *** synthesis of urea is accompanied by a high level of energy consumption while electrocatalytic methods suffer from low yields and poor *** work achieves efficient synthesis of urea by designing the graphene-In_(2)O_(3)electrocatalysts for the co-activated reduction of nitrate and carbon dioxide,where the formation rate of urea,Faraday efficiency(FE)and carbon selectivity at-0.35 V *** can reach 357.47μg mg^(-1)h^(-1),10.46%and~100%,***,the key intermediates in the C–N coupling reaction are demonstrated to be*Nh_(2)and*CO_(2),which is of novelty compared to previous *** work may provide inspiration for subsequent studies on the reaction mechanism of the electrochemical synthesis of urea,as well as theoretical guidance for the sustainable synthesis of some other important chemical substances.

关键词： Graphene-supported In_(2)O_(3) Dispersion effect Efficient C-N coupling Key intermediate Urea

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Safety and efficacy of omalizumab for antihistamine-resistant chronic urticaria in children:a case series and literature review

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World Journal of Pediatrics 2024年第3期20卷 294-298页

作者： wei-Fang Zhu Chen Wang Jian-Jun Qiao Lan-Juan Li Department of Dermatology First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China State Key Laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Center for Infectious DiseasesCollaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

Chronic urticaria(CU)is a common skin disease characterized by the occurrence of wheals,with or without angioedema,lasting more than 6 *** prevalence of CU is about 0.7%[1],but higher in children,with an incidence of 1.38%[1].The occurrence of severe pruritus and unpredictable wheals may severely impact patients'quality of life,cause psychological problems,including sleep disorders and depression,and lead to economic burden due to limitation on daily life and work[2,3].

关键词： edema prevalence children

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The guest Ch_(3)CN molecule triggers solid-state photochromism in a Cu_(2)I_(2)-based MOF for advanced time-dependent encryption and inkless erasable printing

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Chinese Chemical Letters 2024年第3期35卷 532-537页

作者： Meng-Juan Wang Bo Li Yong-Li wei Shu-Na Zhao Shuang-Quan Zang henan Key Laboratory of Crystalline Molecular Functional Materials Henan International Joint Laboratory of Tumor Theranostical Cluster MaterialsGreen Catalysis Centerand College of ChemistryZhengzhou UniversityZhengzhou 450001China College of Chemistry and Pharmaceutical Engineering Nanyang Normal UniversityNanyang 473061China

It remains a big challenge to develop solid-state stimuli-responsive materials for time-dependent information encryption and inkless erasable printing with long retention ***,a 2D Cu_(2)I_(2)-based MOF with photoresponsive spiropyran(SP)groups orderly installed on its skeleton is *** structural isomerization from SP to colored merocyanine(MC)form can be triggered by removing the Ch_(3)CN ***,the degree of structural isomerization and the retention time can be adjusted by controlling the amount of Ch_(3)CN guests,exhibiting dynamic photochromic behavior with multicolor states and tunable retention *** on these advantages,time-dependent information encryption is successfully ***,the long retention time(>72 h)of the MC form under daylight conditions in the Ch_(3)CN-removed Cu_(2)I_(2)-based MOF and good repeatability make it promising in various applications,such as temporary calendars,price-cards,billboards,and reusable identity *** work provides a novel design strategy to fabricate multi-functional MOF-based smart materials for challenging applications of time-dependent information encryption and inkless erasable printing.

关键词： Stimuli-responsive materials Spiropyran Solid-state photochromism Time-dependent encryption Inkless erasable printing

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Low Selenium and Low Protein Exacerbate Myocardial Damage in Keshan Disease by Affecting the PINK1/Parkin-mediated Mitochondrial Autophagy Pathway

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Current Medical Science 2024年第1期44卷 93-101页

作者： Li-wei ZhANG hong-qi FENG Song-bo FU Dian-jun SUN Center for Endemic Disease Control Chinese Center for Disease Control and PreventionHarbin Medical UniversityNHC Key Laboratory of Etiology and Epidemiology(Harbin Medical University)Key Lab of Etiology and EpidemiologyEducation Bureau of Heilongjiang ProvinceHarbin 150086China

Objective Keshan disease(KD)is a myocardial mitochondrial disease closely related to insufficient selenium(Se)and protein *** induced putative kinase 1(PINK1)/Parkin mediated mitochondrial autophagy regulates various physiological and pathological processes in the *** study aimed to elucidate the relationship between PINK1/Parkin-regulated mitochondrial autophagy and KD-related myocardial *** A low Se and low protein animal model was *** hundred Wistar rats were randomly divided into 5 groups(control group,low Se group,low protein group,low Se+low protein group,and corn from KD area group).The JC-1 method was used to detect the mitochondrial membrane potential(MMP).ELISA was used to detect serum creatine kinase MB(CK-MB),cardiac troponin I(cTnI),and mitochondrial-glutamicoxalacetic transaminase(M-GOT)***-PCR and Western blot analysis were used to detect the expression of PINK1,Parkin,sequestome 1(P62),and microtubule-associated proteins1A/1B light chain 3B(MAP1LC3B).Results The MMP was significantly decreased and the activity of CK-MB,cTnI,and M-GOT significantly increased in each experimental group(low Se group,low protein group,low Se+low protein group and corn from KD area group)compared with the control group(Phe mRNA and protein expression levels of PINK1,Parkin and MAP1LC3B were profoundly increased,and those of P62 markedly decreased in the experimental groups compared with the control group(Pxacerbate myocardial damage in KD by affecting the PINK1/Parkin-mediated mitochondrial autophagy pathway.

关键词： Keshan disease low selenium and low protein myocardial mitochondrial injury PTEN induced putative kinase 1(PINK1)/Parkin mitochondrial autophagy

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AIEgen configuration transition and aggregation enable dual prompt emission for single-component nondoped white OLEDs

Aggregate

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Aggregate 2024年第1期5卷 292-298页

作者： Jiasen Zhang Qiang wei wei Li hao Chen xiangyu Zhu Yongqi Bai Nannan Fei Liang Cao Zujin Zhao Anjun Qin Ben Zhong Tang Ziyi Ge Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingboP.R.China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingP.R.China Center for Aggregation-Induced Emission State Key Laboratory of Luminescent Materials and Devices South China University of Technology GuangzhouGuangzhouChina Shenzhen Institute of Aggregate Science and Technology School of Science and EngineeringThe Chinese University of Hong KongShenzhenChina

The dual emission(DE)feature in materials holds great potential to revolutionize the development of one-component system white organic lightemitting diodes(WOLEDs).however,the reported DE materials remain scarce owing to the formidable challenge of breaking Kasha’s rule and managing the intricate energy/charge transfer ***,we have introduced a groundbreaking DE AIEgen,2CzAn-TPE,which possesses a simple structure and undergoes Z-to-E isomerization and exhibits yellow and red fluorescence powders for pre-and post-sublimation,*** relatively lower potential energy,Z-conformation((Z)-1,2-diphenyl-1,2-bis(4-(10-(9-phenyl-9h-carbazol-3-yl)anthracen-9-yl)phenyl)ethene)of 2CzAn-TPE can be readily transformed into E-conformation((E)-1,2-diphenyl-1,2-bis(4-(10-(9-phenyl-9hcarbazol-3-yl)anthracen-9-yl)phenyl)ethene)via vacuum *** utilization of x-ray diffraction and grazing-incidence-wide-angle x-ray scattering techniques confirms the structural transformation,while the crystallographic analysis reveals the establishment of numerous intermolecular Ch⋅⋅⋅πinteractions between the tetraphenylethene(TPE)moiety and both the anthracene and carbazole *** allows a densely packed molecular arrangement,thereby offering propitious conditions for excimer generation in the E-conformation aggregated *** utilizing the sublimated 2CzAn-TPE as an emitter,a nondoped one-component WOLED was prepared,exhibiting an exceptionally high external quantum efficiency(EQE)of 5.0%,which represents one of the highest performances among all *** research introduces a novel,simple,and efficient approach to realize highly efficient one-molecule WOLEDs.

关键词： aggregation-induced emission dual emission isomerization white OLED

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Fe-N-C core-shell catalysts with single low-spin Fe(Ⅱ)-N_(4)species for oxygen reduction reaction and high-performance proton ex.h.nge membrane fuel cells

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Journal of Energy Chemistry 2024年第6期93卷 538-546,I0013页

作者： Yan Wan Linhui Yu Bingxin Yang Caihong Li Chen Fang wei Guo Fang-xing xiao Yangming Lin xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021FujianChina CAS Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021FujianChina Fujian Institute of Research on the Structure of Matter Chinese Academy of SciencesFuzhou 350002FujianChina College of Materials Science and Engineering Fuzhou UniversityNew CampusMinhou 350108FujianChina College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350117FujianChina

Fe-N-doped carbon materials(Fe-N-C)are promising candidates for oxygen reduction reaction(ORR)relative to Pt-based catalysts in proton ex.h.nge membrane fuel cells(PEMFCs).however,the intrinsic contributions of Fe-N_(4)moiety with different chemical/spin states(e.g.D1,D2,D3)to ORR are unclear since various states coexist *** the present work,Fe-N-C core-shell nanocatalyst with single lowspin Fe(Ⅱ)-N_(4)species(D1)is synthesized and identified with ex-situ ultralow temperature Mossbauer spectroscopy(T=1.6 K)that could essentially differentiate various Fe-N_(4)states and invisible Fe-O *** quantifying with CO-pulse chemisorption,site density and turnover frequency of Fe-N-C catalysts reach 2.4×10^(-9)site g^(-1)and 23 e site~(-1)s^(-1)during the ORR,***-wave potential(0.915V_(RhE))of the Fe-N-C catalyst is more positive(approximately 54 mV)than that of Pt/***,we observe that the performance of PEMFCs on Fe-N-C almost achieves the 2025 target of the US Department of Energy by demonstrating a current density of 1.037 A cm^(-2)combined with the peak power density of 0,685 W cm^(-2),suggesting the critical role of Fe(Ⅱ)-N_(4)site(D1).After 500 h of running,PEMFCs still deliver a power density of 1.26 W cm^(-2)at 1.0 bar h_(2)-O_(2),An unexpected rate-determining step is figured out by isotopic labelling experiment and theoretical *** work not only offers valuable insights regarding the intrinsic contribution of Fe-N_(4)with a single spin state to alkaline/acidic ORR,but also provides great opportunities for developing high-performance stable PEMFCs.

关键词： Fuel cells Oxygen reduction reaction Non-platinum group metals(PGMs) Isotopic labelling Active site TOF

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high-Temperature Stability of Mg-1Al-12Y Alloy Containing LPSO Phase and Mechanism of Its Portevin-Le Chatelier(PLC)Effect

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 982-998页

作者： Qian-Long Ren Shuai Yuan Shi-Yu Luan Jin-hui Wang xiao-wei Li xiao-Yu Liu Qinghai Provincial Key Laboratory of New Light Alloys Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and FormingQinghai UniversityXining810016China School of Materials Science and Engineering Shenyang University of TechnologyShenyang110870China

In this study,the high-temperature stability and the generation mechanism of the Portevin-Le Chatelier(PLC)effect in solid-solution Mg-1Al-12Y alloy with different heat treatment processes were investigated by adjusting the content of long-period stacking ordered(LPSO)*** was found that the content of LPSO phases in the alloys differed the most after heat treatment at 530℃for 16 h and 24 h,with values of 13.56%and 3.93%***,high-temperature tensile experiments were conducted on these two alloys at temperatures of 150℃,200℃,250℃,and 300℃.The results showed that both alloys exhibited the PLC effect at temperatures ranging from 150 to 250℃.however,at a temperature 300℃,only the alloy with a greater concentration of LPSO phases exhibited the PLC effect,whereas the alloy with a lower proportion of LPSO phases did not exhibit this ***,both alloys exhibited remarkable high-temperature stability,with the alloy containing a greater percentage of LPSO phases also demonstrating superior *** underlying mechanism for this phenomenon lies in the exceptional high-temperature stability exhibited by the second phase within the ***,the LPSO phase effectively obstructs the movement of dislocations,and it also undergoing kinking to facilitate plastic deformation of the *** results indicate that the PLC effect can be suppressed by reducing dislocation pile-up at grain boundaries,which leads to a decrease in alloy plasticity but an increase in *** presence of the PLC effect in the WA121 alloy is attributed to the abundant dispersed second phase within the alloy,which initially hinders the movement of dislocations,leading to an increase in stress,and subsequently releases the dislocations,allowing them to continue their movement and thereby reducing in stress.

关键词： Magnesium alloy Long-period stacking ordered(LPSO)phase Portevin-Le Chatelier effect high temperature

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In situ meso-tetra(4-carboxyphenyl)porphyrin ligand substitution in hf-MOF for enhanced catalytic activity and stability in photoredox reactions

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Rare Metals 2024年第6期43卷 2682-2694页

作者： Jie hu hong-xin Lao xiu-Wu xu wei-Kang Wang Le-Le Wang Qin-Qin Liu School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China College of Chemistry and Materials Engineering Research Center of Carbon NeutralityAnhui Normal UniversityWuhu 241002China Fujian Provincial Key Laboratory of Ecology-Toxicological Effects and Control for Emerging Contaminants Putian UniversityPutian 351100China

Though there are numerous intrinsic merits of metal-organic frameworks(MOFs),low charge separation efficiency has imposed heavy restrictions on their photocatalytic ***,in situ porphyrin ligand substitution,as a strategy for improving the charge separation efficiency and increasing the amounts of active sites,has been designed and realized in a hf-biphenyl dicarboxylic acid(BPDC)***,a size and geometry matched meso-tetra(4-carboxyphenyl)porphyrin(TCPP)ligand was selected and doped into hf-BPDC MOF by forming coordinating bonds with hf centers,forming dualligand hf-BPDC-TCPP *** resultant hf-BPDC-TCPP MOF showed significantly improved activity and chemical stability in the photocatalytic h_(2)generation(261μmol·g^(-1)·h^(-1))and tetracycline(TC)degradation reactions(95.8%),which was 48 and 1.47 folds higher than that of the hf-BPDC *** and electrochemical studies revealed that the introduction of porphyrin ligand could generate a stronger internal electric field for boosting the charge separation and transfer,increase the specific surface area for providing more active sites,and narrow the band gap to enhance the visible light *** in situ ligand substitution method provides a promising approach to build a tunable platform for constructing high-performance MOF photocatalysts.

关键词： Ligand substitution Metal organic frameworks Meso-tetra(4-carboxyphenyl)porphyrin hydrogen evolution reaction Tetracycline degradation

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