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Cobalamin-dependent radical S-adenosyl-L-methionine protein functions with a partner to successively methylate tricyclic indole alkaloid for chuangxinmycin maturation and derivatization

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Science China Chemistry 2025年第1期 308-316页

作者： Sili Wang Jiancheng Huang Yanan du Wei Huang Yufeng Xue Xiaokun Xu Guannan Zhong Yuanyuan Shi Bin Hong Xiaoying Bian Wen Liu State Key Laboratory of Chemical Biology Shanghai Institute of Organic Chemistry University of Chinese Academy of SciencesChinese Academy of Sciences State Key Laboratory of Microbial Technology Shandong University National Health Commission (NHC) Key Laboratory of Biotechnology for Microbial Drugs Institute of Medicinal BiotechnologyChinese Academy of Medical Science & Peking Union Medical College

Cobalamin(Cbl)-dependent radical S-adenosyl-L-methionine(SAM) proteins constitute the largest collection of the radical SAM superfamily that has hundreds of thousands of individual members. Many of these proteins are involved in the biosynthesis of pharmaceutically important natural products to catalyze chemically demanding reactions. In the biosynthetic pathway of chuangxinmycin(CXM), a unique indole alkaloid antibiotic with potent anti-infective activity, functionalization of the characteristic thiopyrano[4,3,2-cd]indole scaffold by regio-and stereoselective C3-methylation is believed to rely on a Cbl-dependent radical process, which, however, remained to be reconstituted biochemically. We here report the dissection of this enzymatic process, which requires the incorporation of Cxm8, a Cbl-dependent radical SAM protein, with Cxm9, a duF5825family protein that shares no homology to any proteins of known functions. Cxm8 and Cxm9 function together by forming an unexpected heterodimeric complex that selectively catalyzes C3-methylation of the tricyclic indole-S-hetero ring system in a successive manner, achieving CXM and a recently identified, C3-dimethylated congener. Detailed biochemical characterization,isotope labeling, structural simulation and bioinformatics analysis rationalized the catalysis of the Cxm8/Cxm9 complex and particularly the necessity of the duF5825 protein for C3-methylase activity. This is the first example that a Cbl-dependent protein acts with a partner to exhibit radical SAM activity.

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Internet of things intrusion detection model and algorithm based on cloud computing and multi-feature extraction extreme learning machine

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Digital Communications and Networks 2023年第1期9卷 111-124页

作者： Haifeng Lin Qilin Xue jiayin Feng Di Bai Nanjing Forestry University China Nanjing Agricultural University China Hebei Normal University of Science and Technology China

With the rapid development of the Internet of Things(IoT),there are several challenges pertaining to security in IoT *** with the characteristics of the traditional Internet,the IoT has many problems,such as large assets,complex and diverse structures,and lack of computing *** network intrusion detection systems cannot meet the security needs of IoT *** view of this situation,this study applies cloud computing and machine learning to the intrusion detection system of IoT to improve detection ***,traditional intrusion detection algorithms require considerable time for training,and these intrusion detection algorithms are not suitable for cloud computing due to the limited computing power and storage capacity of cloud nodes;therefore,it is necessary to study intrusion detection algorithms with low weights,short training time,and high detection accuracy for deployment and application on cloud *** appropriate classification algorithm is a primary factor for deploying cloud computing intrusion prevention systems and a prerequisite for the system to respond to intrusion and reduce intrusion *** paper discusses the problems related to IoT intrusion prevention in cloud computing *** on the analysis of cloud computing security threats,this study extensively explores IoT intrusion detection,cloud node monitoring,and intrusion response in cloud computing environments by using cloud computing,an improved extreme learning machine,and other *** use the Multi-Feature Extraction Extreme Learning Machine(MFE-ELM)algorithm for cloud computing,which adds a multi-feature extraction process to cloud servers,and use the deployed MFE-ELM algorithm on cloud nodes to detect and discover network intrusions to cloud *** our simulation experiments,a classical dataset for intrusion detection is selected as a test,and test steps such as data preprocessing,feature engineering,model training,an

关键词： Internet of Things Cloud Computing Intrusion Prevention Intrusion Detection Extreme Learning Machine

Mesoporous Bioglass/Silk Fibroin Scaffolds as a Drug Delivery System: Fabrication, Drug Loading and Release in vitro and Repair Calvarial Defects in vivo

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Journal of Wuhan University of Technology(Materials Science) 2014年第2期29卷 401-406页

作者：张晓欣 ZHANG jiayin 施斌 Hospital of Stomatology Wuhan University

The potential of combining bioactive glass（MBG） and silk fibroin（SF） together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method was adopted to fabricate MBG in this study. The characteristic of the synthesized material was measured by transmission electron microscopy and scanning electron microscopy. In vitro evaluation of drug delivery was carried out in terms of drug loading and drug release. And aspirin was chosen as the drug for scaffolds to carry out in vitro tests and repair BALB/C mice calvarial defects. Bone formation was examined by microcomputed tomography. The experimental results show that MBG/silk scaffolds have better physiochemical properties compared with silk scaffolds. In comparison to pure silk scaffolds, MBG/silk scaffolds enhance the drug loading efficiency, release rate in vitro and promote bone regeneration in vivo. Thus we conclude that MBG/silk scaffold is a more efficient drug delivery system than pure silk scaffolds.

关键词： silk fibroin mesoporous bioactive glass drug delivery calvarial defect aspirin

Complicated target recognition by archaeal box C/D guide RNAs

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Science China(Life Sciences) 2024年第4期67卷 631-644页

作者： jiayin Wang Songlin Wu Keqiong Ye Key Laboratory of RNA Science and Engineering CAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Box C/D RNAs guide the site-specific formation of 2′-O-methylated nucleotides(Nm)of RNAs in eukaryotes and *** C/D RNAs have been profiled in several archaea,their targets have not been experimentally ***,we mapped Nm in r RNAs,t RNAs,and abundant small RNAs(s RNAs)and profiled C/D RNAs in the crenarchaeon Sulfolobus *** targets of C/D RNAs were assigned by analysis of base-pairing interactions,in vitro modification assays,and gene deletion experiments,revealing a complicated landscape of C/D RNA-target interactions.C/D RNAs widely use dual antisense elements to target adjacent sites in r RNAs,enhancing modification at weakly bound *** consecutive sites can be guided with the same antisense element upstream of box D or D′,a phenomenon known as doublespecificity that is exclusive to internal box D′in eukaryotic C/D *** C/D RNAs guide modification at a single non-canonical *** study reveals the global landscape of RNA-guided 2′-O-methylation in an archaeon and unexpected targeting rules employed by C/D RNA.

关键词： C/D RNA 2′-O-methylation archaea guide RNA RNA modification

Improved mechanical, degradation, and biological performances of Zn–Fe alloys as bioresorbable implants

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Bioactive Materials 2022年第11期7卷 334-343页

作者： Yingchao Su jiayin Fu Wonsae Lee Shaokang du Yi-Xian Qin Yufeng Zheng Yadong Wang Donghui Zhu Department of Biomedical Engineering Stony Brook UniversityStony BrookNYUSA Nancy E.and Peter C.Meinig School of Biomedical Engineering Cornell UniversityIthacaNYUSA Department of Cardiology Sir Run Run Shaw HospitalZhejiang UniversityHangzhouZhejiangChina Academy for Advanced Interdisciplinary Studies Peking UniversityBeijingChina School of Materials Science and Engineering Peking UniversityBeijingChina

Zinc(Zn)is a promising bioresorbable implant material with more moderate degradation rate compared to magnesium(Mg)and iron(Fe).However,the low mechanical strength and localized degradation behavior of pure Zn limit its clinical *** is one of the most effective ways to overcome these *** screening the alloying element candidates regarding their potentials for improvement on the degradation and biocompatibility,we proposed Fe as the alloying element for Zn,and investigated the in vitro and in vivo performances of these alloys in both subcutaneous and femoral *** showed that the uniformly distributed secondary phase in Zn–Fe alloys significantly improved the mechanical property and facilitated uniform degradation,which thus enhanced their biocompatibility,especially the Zn-0.4Fe ***,these Zn–Fe alloys showed outstanding antibacterial *** together,Zn–Fe alloys could be promising can-didates as bioresorbable medical implants for various cardiovascular,wound closure,and orthopedic applications.

关键词： Zinc Mechanical Degradation Biocompatibility Antibacterial

Inhibition effects of perfluoroalkyl acids on progesterone production in mLTC-1

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Journal of Environmental Sciences 2017年第6期29卷 272-280页

作者： Wei Zhao Ruina Cui Jianshe Wang jiayin Dai Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China

Perfluoroalkyl substances （PFASs） are a class of fluorine substituted carboxylic acid, sulfonic acid and alcohol, structurally similar to their corresponding parent compounds. Previous study demonstrated the potential endocrine disruption and reproductive toxicity of perfluorooctane sulfonic acid and perfluorooctanoic acid, two dominant PFASs in animals and humans. We explored the relationship between eleven perfluoroalkyl acids （PFAAs） with different carbon chain length and their ability to inhibit progesterone production in mouse Leydig tumor cells （mLTC-1）. We found an obvious dose-response relationship between progesterone inhibition rate and PFAA exposure concentration in mLTC-1. The relative inhibition rate of progesterone by PFAAs was linearly related to the carbon chain length and molar refractivity of PFAAs. Mitochondrial membrane potential （MMP） decreased after PFAA exposure at the half-maximal inhibitory effect concentration （IC50） of progesterone production in mLTC-1, while the reactive oxygen species （ROS） content increased significantly. These results imply that the inhibition effect of PFAAs on progesterone production might be due, in part, to ROS damage and the decrease in MMP in mLTC-1.

关键词： Perfluoroalkyl substancesProgesteroneMitochondrial membrane potentialReactive oxygen species

Toxic effects of perfluorononanoic acid on the development of Zebrafish(Danio rerio) embryos

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Journal of Environmental Sciences 2015年第6期27卷 26-34页

作者： Hui Liu Nan Sheng Wei Zhang jiayin Dai Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences University of Chinese Academy of Sciences

Perfluorononanoic acid（PFNA） is a nine-carbon perfluoroalkyl acid widely used in industrial and domestic products. It is a persistent organic pollutant found in the environment as well as in the tissues of humans and wildlife. There is a concern that this chemical might be a developmental toxicant and teratogen in various ecosystems. In the present study,the toxic effects of PFNA were evaluated in zebrafish（Danio rerio） embryos. One hour post-fertilization embryos were treated with 0, 25, 50, 100, 200, 300, 350, and 400 μmol/L PFNA for 96 hr in 6-well plates. Developmental phenotypes and hatching rates were observed and recorded. Nineteen genes related to oxidative stress and lipid metabolism were examined using Quantitative RT-PCR and confirmed by whole mount in situ hybridization（WISH）. Results showed that PFNA delayed the development of zebrafish embryos, reduced the hatching rate, and caused ventricular edema and malformation of the spine. In addition, the amount of reactive oxygen species in the embryo bodies increased significantly after exposure to PFNA compared with that of the control group. The Quantitative RT-PCR and WISH experiments demonstrated that m RNA expression of the lfabp and ucp2 genes increased significantly while that of sod1 and mt-nd1 decreased significantly after PFNA exposure. The m RNA expression levels of gpx1 and mt-atp6 decreased significantly in the high concentration group. However, the m RNA expression levels of both ppara and pparg did not show any significant variation after exposure. These findings suggest that PFNA affected the development of zebrafish embryos at relatively low concentrations.

关键词： Perfluorononanoic acid Zebrafish embryo Danio rerio Developmental toxicity

Effects of pentachlorophenol on the detoxification system in white-rumped munia(Lonchura striata)

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Journal of Environmental Sciences 2016年第6期28卷 224-234页

作者： Peng Jiang Jianshe Wang Jinguo Zhang jiayin Dai Key Laboratory of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China Beijing Zoo Beijing 100044 China

Pentachlorophenol（PCP）, a priority pollutant due to its persistence and high toxicity, has been used worldwide as a pesticide and biocide. To understand the adverse effects of PCP, adult male white-rumped munias（Lonchura striata） were orally administrated commercial PCP mixed with corn oil at dosages of 0, 0.05, 0.5, and 5 mg/（kg·day） for 42 day. Gas chromatography–mass spectrometry（GC–MS） analysis found that PCP was preferentially accumulated in the kidney rather than in the liver and muscle in all exposure groups. To examine the function of CYP1A in pollutant metabolism, we isolated two full-length cDNA fragments（designated as CYP1A4 and CYP1A5） from L. striata liver using reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends. PCP induced the expression of CYP1A5, although no obvious change was observed in CYP1A4 expression. Furthermore, PCP significantly elevated the activities of ethoxyresorufin O-deethylase and methoxyresorufin O-demethylase and decreased the activity of benzyloxy-trifluoromethyl-coumarin, with no significant responses observed in benzyloxyresorufin O-debenzylase. PCP induced significant changes in antioxidant enzyme（superoxide dismutase and catalase） activities and malondialdehyde content, but decreased glutathione peroxidase（GSH-Px） and glutathione S-transferase activities and GSH content in the liver of L. striata. The present study demonstrated that PCP had hepatic toxic effects by affecting CYP1As and anti-oxidative status.

关键词： CYP1A4 CYP1A5 Alkoxyresorufin O-dealkylase Antioxidant enzyme Lonchura striata

Recent Advances in Fibrous Materials for Hydroelectricity Generation

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Nano-Micro Letters 2025年第2期17卷 109-133页

作者： Can Ge duo Xu Xiao Feng Xing Yang Zheheng Song Yuhang Song Jingyu Chen Yingcun Liu Chong Gao Yong du Zhe Sun Weilin Xu Jian Fang College of Textile and Clothing Engineering Soochow UniversitySuzhou 215123People’s Republic of China National Engineering Laboratory for Modern Silk Soochow UniversitySuzhou 215123People’s Republic of China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200People’s Republic of China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123People’s Republic of China Department of Electrical and Computer Engineering University of MassachusettsAmherstMA 01003USA Department of Materials Imperial College LondonSouth Kensington CampusLondon SW72AZUK College of Textile Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China School of Materials Science and Engineering Shanghai Institute of Technology100 Haiquan RoadShanghai 201418People’s Republic of China

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable *** generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy *** materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first ***,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are ***,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in ***,the potential applications including power supply,energy storage,electrical sensor,and information expression are also ***,some existing challenges are considered and prospects for future development are sincerely proposed.

关键词： Hydroelectricity Fibrous material Streaming potential Ion diffusion