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Temperature Effect on the conformation Transition of Ultra-high Molecular Weight Polyethylene/Polypropylene Blends Undergoing Continuous Volume Extensional Flow:A Mesoscopic Simulation

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Journal of Wuhan University of Technology(Materials Science) 2022年第3期37卷 540-545页

作者： WANG Junxia YAN Shilin YU Dingshan Key laboratory for Polymeric Composite and Functional Materials of Ministry of Education and Key laboratory of High Performance Polymer-based Composites of Guangdong Province School of ChemistrySun Yat-Sen UniversityGuangzhou510275China Hubei Key laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan 430070China

Due to the multiformity and complexity of chain conformation under external flow and the challenge of systematically investigating the transient conformation and dynamic evolution process of polymer chains at the molecular level by means of present experimental techniques,a universal description of both chain conformation and dynamics with respect to continuous volume extensional flow(CVEF)is still *** into account the temperature effect,we performed dissipative particle dynamics(DPD)simulations with the particles corresponding to the repeat units of polymers over a wide temperature range and analyzed the correlation with the conformational properties of ultra-high molecular weight polyethylene/polypropylene(UHMWPE/PP)blend in response to the *** time evolution,the polymer chains become highly oriented parallel to the flow direction instead of the initial random coiling and *** is found that a high temperature is necessary for more substantial compactness to take place than low *** low-k plateau and low-k peak in structure factor S(k)curves suggest a low degree of conformational diversity and a high degree of chain *** is also concluded that the intra-molecular C-C bond interaction is the main driving force for the dynamics process of the chain conformations undergoing CVEF,where the motion of the alkyl chains is seriously restricted owing to the increase in bond interaction potential,resulting in a reduction of the difference in diffusion rates among alkyl chains.

关键词： temperature effect dissipative particle dynamics ultra-high molecular weight polyethylene polypropylene volume extensional flow chain conformation blends

Influence of Substrate conformation on the Deglycosylation of Ribonuclease B by Recombinant Yeast Peptide:N-glycanase

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Acta Biochimica et Biophysica Sinica 2007年第1期39卷 8-14页

作者： Shengjun WANG Peng George WANG and Qingsheng QI State Key laboratory of Microbial Technology,Life Science Schooll,Shandong University,Jinan 250100,China State Key laboratory of Microbial Technology Life Science School Shandong UniversityJinan 250100 China

Peptide:N-glycanase has been thought to be responsible for proteasome-dependent degradationof misfolded glycoproteins translocated from the endoplasmic reticulum (ER) to the ***,theenzyme was supposed to be able to distinguish between native and non-native *** the presentstudy,a recombinant,yeast peptide:N-glycanase,Png lp, was expressed in Escherichia coli as inclusionbodies and was purified,refolded and *** results showed that the recombinant enzymehas a broad pH range adaptation,from pH 4.0 to pH 10.0,and has an optimum temperature of 30 ℃.This enzyme is a zinc *** activity was abolished with the addition of EDTA and notrestored by adding metal ***,the deglycosylation efficiency of recombinant Pnglpfrom *** was investigated with respect to the substrate conformation in *** ribonuclease B(RNase B) was denatured at 60-65 ℃ or by 40-60 mM dithiothreitol, indicated by its obvious structuralchange and sharpest activity change,its deglycosylation by Pnglp was most *** deglycosylationefficiency of RNase B by Pnglp was found to be related to its structural conformation and enzymaticactivity.

关键词： glycanase ribonuclease B glycoprotein deglycosylation circular dichroism

Crystal structure of cytotoxin protein suilysin from Streptococcus suis

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protein & Cell 2010年第1期1卷 96-105页

作者： Lingfeng Xu Bo Huang Huamao Du Xuejun CZhang Jianguo Xu Xuemei Li Zihe Rao National laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of Sciences15 Datun RoadBeijing 100101China College of Biotechnology Southwest UniversityChongqing 400715China State Key laboratory for Infectious Disease Prevention and Control National Institute for Communicable Disease Control and PreventionBeijing 102200China protein Studies Program Oklahoma Medical Research Foundation825 N.E.13th streetOklahoma CityOK 73104USA

Cholesterol-dependent cytolysins(CDC)are pore forming toxins.A prototype of the CDC family members is perfringolysin O(PFO),which directly binds to the cell membrane enriched in cholesterol,causing cell ***,an exception of this general observation is intermedilysin(ILY)of Streptococcus intermedius,which requires human CD59 as a receptor in addition to cholesterol for its hemolytic activity.A possible explanation of this functional difference is the conformational variation between the C-terminal domains of the two toxins,particularly in the highly conserved undecapeptide termed tryptophan rich ***,we present the crystal structure of suilysin,a CDC toxin from the infectious swine pathogen Streptococcus *** PFO,suilysin does not require a host receptor for hemolytic activity;yet the crystal structure of suilysin exhibits a similar conformation in the tryptophan rich motif to *** observation suggests that the current view of the structure-function relationship between CDC proteins and membrane association is far from complete.

关键词： suilysin cholesterol-dependent cytolysin crystal structure

protein lipidation in health and disease:molecular basis,physiological function and pathological implication

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1423-1465页

作者： Yuan Yuan Peiyuan Li jianghui Li Qiu Zhao Ying Chang Xingxing He Department of Gastroenterology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina Department of Gastroenterology Zhongnan Hospital of Wuhan UniversityWuhanChina Hubei Clinical Center and Key laboratory of Intestinal and Colorectal diseases WuhanChina

Posttranslational modifications increase the complexity and functional diversity of proteins in response to complex external stimuli and internal *** these,protein lipidations which refer to lipid attachment to proteins are prominent,which primarily encompassing five types including S-palmitoylation,N-myristoylation,S-prenylation,glycosylphosphatidylinositol(GPl)anchor and *** attachment to proteins plays an essential role in the regulation of protein trafficking,localisation,stability,conformation,interactions and signal transduction by enhancing *** evidence from genetic,structural,and biomedical studies has consistently shown that protein lipidation is pivotal in the regulation of broad physiological functions and is inextricably linked to a variety of *** of dedicated research have driven the development of a wide range of drugs targeting protein lipidation,and several agents have been developed and tested in preclinical and clinical studies,some of which,such as asciminib and lonafarnib are FDA-approved for therapeutic use,indicating that targeting protein lipidations represents a promising therapeutic ***,we comprehensively review the known regulatory enzymes and catalytic mechanisms of various protein lipidation types,outline the impact of protein lipidations on physiology and disease,and highlight potential therapeutic targets and clinical research progress,aiming to provide a comprehensive reference for future protein lipidation research.

关键词： Lipid ation primarily

An ultrapotent pan-β-coronavirus lineage B(β-CoV-B)neutralizing antibody locks the receptor-binding domain in closed conformation by targeting its conserved epitope

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protein & Cell 2022年第9期13卷 655-675页

作者： Zezhong Liu Wei Xu Zhenguo Chen Wangjun Fu Wuqiang Zhan Yidan Gao Jie Zhou Yunjiao Zhou Jianbo Wu Qian Wang Xiang Zhang Aihua Hao Wei Wu Qianqian Zhang Yaming Li Kaiyue Fan Ruihong Chen Qiaochu Jiang Christian TMayer Till Schoofs Youhua Xie Shibo Jiang Yumei Wen Zhenghong Yuan Kang Wang Lu Lu Lei Sun Qiao Wang Key laboratory of Medical Molecular Virology(MOE/NHC/CAMS) School of Basic Medical SciencesShanghai Institute of Infectious Disease and Biosecuritythe Fifth People’s Hospital of ShanghaiShanghai Key Laboratory of Medical EpigeneticsInternational Co-laboratory of Medical Epigenetics and Metabolism(Ministry of Science and Technology)Institutes of Biomedical SciencesBiosafety Level 3 LaboratoryShanghai Medical CollegeFudan UniversityShanghai 200032China CAS Key laboratory of Infection and Immunity National Laboratory of MacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China Experimental Immunology Branch Center for Cancer ResearchNational Cancer InstituteNational Institutes of HealthBethesdaMD 20892USA GSK Vaccines 1300 WavreBelgium

New threats posed by the emerging circulating variants of SARS-CoV-2 highlight the need to find conserved neutralizing epitopes for therapeutic antibodies and efficient vaccine ***,we identified a receptorbinding domain(RBD)-binding antibody,XG014,which potently neutralizesβ-coronavirus lineage B(β-CoV-B),including SARS-CoV-2,its circulating variants,SARSCoV and bat SARSr-CoV ***,antibody family members competing with XG014 binding show reduced levels of cross-reactivity and induce antibodydependent SARS-CoV-2 spike(S)protein-mediated cellcell fusion,suggesting a unique mode of recognition by *** analyses reveal that XG014 recognizes a conserved epitope outside the ACE2 binding site and completely locks RBD in the non-functional“down”conformation,while its family member XG005 directly competes with ACE2 binding and position the RBD“up”.Single administration of XG014 is effective in protection against and therapy of SARS-CoV-2 infection in *** findings suggest the potential to develop XG014 as pan-β-CoV-B therapeutics and the importance of the XG014 conserved antigenic epitope for designing broadly protective vaccines againstβ-CoV-B and newly emerging SARS-CoV-2 variants of concern.

关键词： SARS-CoV-2 neutralizing antibody receptor-binding domain XG014 antibody-dependent cellcell fusion

In cell measurement of fluorescence lifetime imaging microscopy revealed C-terminal conformation changes of Ferroportin upon addition of Mn^2＋

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Chinese Chemical Letters 2018年第10期29卷 1509-1512页

作者： Mengge Zhang Ming Wen Ying Xiong Longhua Zhang Changlin Tian National laboratory of Physical Sciences at Microscale and School of Life Sciences University of Science and Technology of China Hefei 230027 China High Magnetic Field laboratory Chinese Academy of Sciences Hefei 230031 China

Fluorescence microscopy, as a sensitive method to detect microenvironment of molecules, is widely used in protein conformation and dynamic studies in live cells. Fluorescence lifetime imaging microscopy（FLIM）, which is independent of fluorophore concentrations, scattering and bleaching, is a suitable tool to analyze membrane proteins in a single cell. Ferroportin（FPN）, a multi-ion exporter in vertebrates, was modulated by metal ions with unknown mechanism. Herein, we fused green fluorescence protein on Cterminal of FPN（FPN-eGFP） and applied fluorescence lifetime to monitor conformation changes of FPN in a live cell. The fluorescence lifetime distribution showed a shift to shorter lifetime upon Mn^（2＋） treatment,suggesting a preference conformation of FPN in Mn^（2＋） exposure. It is also observed that the lifetime（rather than intensity） measurement was not strongly influenced by laser power. The observed fluorescence lifetime changes of FPN-eGFP upon Mn^（2＋） treatments indicated that extracellular metal ions can modulate FPN through conformation exchanges between several different states.

关键词： Fluorescence lifetime imaging microscopy In cell analysis of conformation change Ferroprotin

On the stochastic dynamics of molecular conformation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第9期8卷 1401-1407页

作者： DENG Mao-lin ZHU Wei-qiu Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

An important functioning mechanism of biological macromolecules is the transition between different conformed states due to thermal fluctuation. In the present paper, a biological macromolecule is modeled as two strands with side chains facing each other, and its stochastic dynamics including the statistics of stationary motion and the statistics of conformational transition is studied by using the stochastic averaging method for quasi Hamikonian systems. The theoretical results are confirmed with the results from Monte Carlo simulation.

关键词： Biological macromolecule Thermal fluctuation Stationary statistics Transition time Stochastic averaging method

Synthesis and Characteristics of an Aspartame Analogue,L-Asparaginyl L-3-Phenyllactic Acid Methyl Ester

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Acta Biochimica et Biophysica Sinica 2004年第6期36卷 385-389页

作者： Hu TAO1, Da-Fu CUI1, and You-Shang ZHANG1,2* 1Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China Institute of protein Research, Tongji University, Shanghai 200031, China Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Graduate School of the Chinese Academy of SciencesShanghai 200031 China Institute of protein Research Tongji UniversityShanghai 200031 China

An aspartame analogue, L-asparaginyl L-3-phenyllactic acid methyl ester was synthesized with aspartic acid replaced by asparagine and peptide bond replaced by ester bond. The aspartic acid of aspartame could be replaced by asparagine as reported in the literature. In this analogue, the hydrogen of amide group could still form a hydrogen bond with the oxygen of ester bond and the ester bond was isosteric with peptide bond. However, the product was not sweet, showing that the peptide bond could not be replaced by ester bond. The peptide C-N bond behaves as a double bond that is not free to rotate and the C, O, N and H atoms are in the same plane. The replacement of peptide bond by ester bond destroyed the unique conformation of peptide bond, resulting in the loss of sweet taste.

关键词： artificial sweetener aspartame derivative peptide bond

EFFECT OF TRANSMEMBRANE Ca^(2+) GRADIENT ON conformation AND ENZYME ACTIVITY OF RECONSTITUTED ADENYLATE CYCLASE

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Science China Chemistry 1992年第1期35卷 67-75页

作者：屠亚平杨福愉 National laboratory of Biomacromolecules Institute of Biophysics Academia Sinica Beijing 100080 PRC

Adenylate cyclase from bovine brain cortex was reconstituted into asolectin liposomes with (500-fold) or without transmembrane Ca^(2+) gradient. The enzyme activity of four types of proteoliposomes (the active center of enzyme exposing outside) was compared. The highest adenylate cyclase activity was observed in the vesicles with outside lower Ca^(2+)concentration (≈10^(-6) mol/L, similar to thephysiological condition). If the transmembrane Ca^(2+) gradient was in the inverse direction (i.e. outside higher Ca^(2+) concentration, 0.5 mmol/L), a lowest enzymatic activity would appear. The difference in enzymatic activity between the two types of proteoliposomes could be diminished following the addition of Ca^(2+) ionophore A23187. Proteoliposomes without transmembrane Ca^(2+) gradient exhibited intermediate *** conformation difference of adenylatecyclases in the above-mentioned proteoliposomes was also detected by measuring intrinsic fluorescence and fluorescence quenching with KI.

关键词： Adenylate cyclase proteoliposomes transmembrane Ca^(2+) gradient.