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Molecular Plant 2011年第5期4卷 879-885页

作者： Chuanmei Zhu Ram Dixit Biology Department Washington University St Louis MO 63130 USA

The Arabidopsis FRA1 kinesin contributes to the organization of cellulose microfibrils through an unknown mechanism. The cortical localization of this kinesin during interphase raises the possibility that it transports cell wallrelated cargoes along cortical microtubules that either directly or indirectly influence cellulose microfibril patterning. To determine whether FRA1 is an authentic motor protein, we combined bulk biochemical assays and single molecule fluorescence imaging to analyze the motor properties of recombinant, GFP-tagged FRA1 containing the motor and coiled-coil domains （designated as FRAI（707）-GFP）. We found that FRAI（707）-GFP binds to microtubules in an ATP-dependent manner and that its ATPase activity is dramatically stimulated by the presence of microtubules. Using single molecule studies, we found that FRAI（707）-GFP moves processively along microtubule tracks at a velocity of about 0.4 μm s-1. In addition, we found that FRAI（707）-GFP is a microtubule plus-end-directed motor and that it moves along microtubules as a dimer. Interestingly, our single molecule analysis shows that the processivity of FRAI（707）-GFP is at least twice the processivity of conventional kinesin, making FRA1 the most processive kinesin to date. Together, our data show that FRA1 is a bona fide motor protein that has the potential to drive Iong-distance transport of cargo along cortical microtubules.

关键词： Kinesin FRA1 cortical microtubule single molecule cellulose Arabidopsis.

Visualized SERS Imaging of single molecule by Ag/ Black Phosphorus Nanosheets

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Nano-Micro Letters 2022年第5期14卷 47-61页

作者： Chenglong Lin Shunshun Liang Yusi Peng Li Long Yanyan Li Zhengren Huang Nguyen Viet Long Xiaoying Luo Jianjun Liu Zhiyuan Li Yong Yang State Key Laboratory of High‑Performance Ceramics and Superfine Microstructures Shanghai Institute of CeramicsChinese Academy of Sciences1295 Dingxi RoadShanghai 200050People’s Republic of China Graduate School of the Chinese Academy of Sciences No.19(A)Yuquan RoadBeijing 100049People’s Republic of China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China State Key Laboratory of Oncogenes and Related Genes Shanghai Cancer InstituteRenji HospitalShanghai Jiaotong University School of Medicine200032 ShanghaiPeople’s Republic of China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510641People’s Republic of China Department of Electronics and Telecommunications Saigon UniversityHochiminh CityVietnam

single-molecule detection and imaging are of great value in chemical analysis,biomarker identification and other trace detection ***,the localization and visualization of single molecule are still quite a ***,we report a special-engineered nanostructure of Ag nanoparticles embedded in multi-layer black phosphorus nanosheets(Ag/BP-NS)synthesized by a unique photoreduction method as a surfaceenhanced Raman scattering(SERS)*** a SERS substrate features the lowest detection limit of 10^(–20) mol L^(−1) for R6G,which is due to the three synergistic resonance enhancement of molecular resonance,photoinduced charge transfer resonance and electromagnetic *** propose a polarization-mapping strategy to realize the detection and visualization of single *** addition,combined with machine learning,Ag/BP-NS substrates are capable of recognition of different tumor exosomes,which is meaningful for monitoring and early warning of the *** work provides a reliable strategy for the detection of single molecule and a potential candidate for the practical bio-application of SERS technology.

关键词： Black phosphorus single molecule SERS Exosome Machine learning

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Theory on single molecule-photon cryocooler——Conception and quantum transition processes

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Science China Mathematics 2001年第1期44卷 113-119页

作者：秦伟平杜国同许武陈宝玖秦冠仕黄世华 1. Changchun Institute of Optical Fine Mechanics and Physics Chinese Academy of Sciences China 1. Laboratory of Excited State Processes Chinese Academy of Sciences 130021 Ghangchun China 2. Electronic Engineering Department Jilin University China 2. National Integrated Optoelectronics Laboratory Jilin University 130023 Changchun China

The micro mechanism of anti-Stokes fluorescent cooling was investigated on molecular or ionic scale. A new conception of single molecule-photon cryocooler (SMPC) was given, and the smallest cryocooler in the world was predicted. We described SMPC and its running principle in detail. The quantum transition processes of SMPC and the largest cooling coefficient that SMPC can get in an optical transition were given. Also we studied the random property of SMPC in cooling processes. The thermodynamic behavior of single Yb3+ ion as a photon cryocooler was imitated.

关键词： single molecule ion cryocooler laser cooling anti-Stokes fluorescent cooling.

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Studying structure and functions of cell membranes by single molecule biophysical techniques

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Biophysics Reports 2021年第5期7卷 384-398页

作者： Qingrong Zhang Siying Li Yu Yang Yuping Shan Hongda Wang School of Chemistry and Life Science Advanced Institute of Materials Science Changchun University of Technology State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Cell membranes are complicated multicomponent structures, related to many basic cellular processes,such as substance transporting, energy conversion, signal transduction, mechanosensing, cell adhesion and so on. However, cell membranes have long been difficult to study at a single-molecule level due to their complex and dynamic properties. During the last decades, biophysical imaging techniques, such as atomic force microscopy and super-resolution fluorescent microscopy, have been developed to study biological structures with unprecedented resolution, enabling researchers to analyze the composition and distribution of membrane proteins and monitor their specific functions at single cell/molecule level. In this review, we highlight the structure and functions of cell membranes based on up-to-date biophysical techniques. Additionally, we describe the recent advances in force-based detecting technology, which allow insight into dynamic events and quantitativelymonitoring kinetic parameters for trans-membrane transporting in living cells.

关键词： Atomic force microscopy single molecule Cell membrane Super-resolution fluorescence microscopy single molecule force spectroscopy

Toward Imaging Defect-Mediated Energy Transfer between single Nanocrystal Donors and single molecule Acceptors

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CHEMICAL & BIOMEDICAL IMAGING 2023年第2期1卷 168-178页

作者： Lustig, Danielle R. Nilsson, Zach N. Mulvey, Justin T. Zang, Wenjie Pan, Xiaoqing Patterson, Joseph P. Sambur, Justin B. Colorado State Univ Dept Chem Ft Collins CO 80523 USA Univ Calif Irvine Ctr Complex & Act Mat Irvine CA 92697 USA Univ Calif Irvine Dept Mat Sci & Engn Irvine CA 92697 USA Univ Calif Irvine Dept Mat Sci & Engn Irvine Mat Res Inst Irvine CA 92697 USA Colorado State Univ Sch Adv Mat Discovery Ft Collins CO 80523 USA

Defect-mediated energy transfer is an energy transfer process between midgap electronic states in a semiconductor nanocrystal (NC) and molecular acceptors, such as fluorescent dye molecules. Super-resolution fluorescence microscopy represents an exciting technique for pinpointing the nanoscale positions of lattice defect sites in, for example, a micrometer-sized particle or thin film sample by spatially resolving the location of the acceptor dye molecules with nanometer resolution. Toward this goal, our group performed ensemble-level, time-resolved fluorescence spectroscopy measurements of ZnO NC/Alexafluor 555 (A555) mixtures and calculated that the emissive defect sites are located, on average, 0.5 nm from the NC surface [Nilsson, Z. N.;et al. J. Chem. Phys. 2021, 154 (5), 054704]. However, ensemble-level measurements cannot spatially resolve the defect sites on single particles, nor can they distinguish between surface-adsorbed dye molecules that participate in the energy transfer (EnT) process from those that do not. In this work, we compared the photoluminescence intensity trajectories of 789 isolated, single ZnO NC donors to those of 73 non-specifically bound and five specifically bound ZnO NC/A555 pairs, where the donor and acceptor centroid positions were separated by a distance that was smaller than our localization precision (40 nm). We observed minor fluorescence intensity fluctuations in the donor and defect channels instead of clear anticorrelated intensity fluctuations, which could be explained by (1) the presence of multiple emissive defect sites per NC, (2) donor-acceptor separation distances slightly larger than the Forster radius (R-0 = 3.1 nm;defined as the distance at which EnT is 50% efficient), and/or (3) poor dipole-dipole coupling. The single molecule imaging methodology we developed, an alternating ultraviolet-visible excitation sequence combined with multicolor photon detection, successfully distinguishes specifically bound and non-specific

关键词： defects single molecule FRET super-resolution ZnO energy transfer

Interaction Study between DNA and Histone Proteins on single-molecule Level using Atomic Force Microscopy

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Chinese Journal of Chemical Physics 2014年第1期27卷 115-120,I0004页

作者：刘玉颖王鹏业窦硕星吕洪凤中国农业大学理学院北京100083 中国科学院物理研究所软物质物理实验室北京100190

DNA and histone protein are important in the formation of nucleosomal arrays, which are the first packaging level of DNA into a more compact chromatin structure. To characterize the interactions of DNA and histone proteins, we reconstitute nucleosomes using lambda DNA and whole histone proteins by dialysis and perform direct atomic force microscopy （AFM） imaging. Compared with non-specific DNA and histone binding, nucleosomes are formed within the assembled “beads-on-a-string” nucleosomal array by dialysis. These observations facilitate the establishment of the molecular mechanisms of nucleosome and demonstrate the capability of AFM for protein-DNA interaction analysis.

关键词： DNA Histone Atomic force microscopy single molecule Dialysis

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Measuring the Stoichiometry of Functional PspA Complexes in Living Bacterial Cells by single molecule Photobleaching

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Measuring the Stoichiometry of Functional PspA Complexes in ...

A versatile platform for single-molecule enzymology of restriction endonuclease

第一届全国生物物理化学会议暨生物物理化学发展战略研讨会

作者： Tchern Lenn Christos N.Gkekas Laurent Bernard Christoph Engl Goran Jovanovic Martin Buck Centre for Bioinformatics Division of Molecular Biosciences Imperial College London

＜正＞Proteins often function as multimeric complexes in cellular processes such as signal transduction and ion *** well-established techniques exist to determine the structure and composition of protein complexes in their isolated forms in vitro,yet it is challenging to measure the stoichiometry of functional complexes in living *** we

关键词： single molecule stoichiometry photobleaching fluorescence imaging

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Journal of Innovative Optical Health Sciences 2019年第1期12卷 29-38页

作者： Xin Wang Jingyuan Nie Yi Li Hai Pan Peng Zheng Meng Qin Yi Cao Wei Wang National Laboratory of Solid State Microstructure School of Physics Nanjing University 22 Hankou Road NanjingJiangsu 210093P.R.China School of Chemistry and Chemical Engineering Nanjing University 163 Xianlin Avenue Nanjing Jiangsu 210023P.R.China

Enzymes are the major players for many biological *** studies of the enzymatic activity at the single-molecule level provides important information that is otherwise inaccessible at the ensemble ***,these single-molecule experiments are technically di±cult and generally require complicated experimental ***,we develop a Holliday junction(HJ)-based platform to study the activity of restriction endonucleases at the single-molecule level using single-molecule FRET(sm-FRET).We show that the intrinsic dynamics of HJ can be used as the reporter for both the enzyme-binding and the substrate-release *** to the multiple-arms structure of HJ,the fluorophore-labeled arms can be different from the surface anchoring arm and the substrate ***,it is possible to independently change the substrate arm to study different enzymes with similar *** a design is extremely useful for the systematic study of enzymes from the same family or enzymes bearing different pathologic ***,this method can be easily extended to study other types of DNA-binding enzymes without too much modi fication of the *** anticipate it can find broad applications in single-molecule enzymology.

关键词： single molecule Forster resonance energy transfer enzymology kinetics holliday junction

Subdomain specific collapse of denatured states of staphylococcal nuclease revealed by single molecule FRET

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Subdomain specific collapse of denatured states of staphyloc...

Harvesting Mechanical Work From Folding-Based Protein Engines: From single-molecule Mechanochemical Cycles to Macroscopic Devices

第二届全国“跨学科蛋白质研究”学术讨论会

作者：孟祥兰赵新生 Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable Speciesand Department of Chemical BiologyCollege of Chemistry and Molecular EngineeringPeking University

We have used muiti-site single molecule FRET to explore the collapse of SNase (Staphylococcal Nuclease, anα/βprotein) in equilibrium *** variants were constructed to explore the total protein (C28C124) and theβbarrel subdomain (C28C97).Both variants exhibited continuous collapse with decreasing denaturant concentrations, as Figurel showed.

关键词： single molecule FRET protein folding staphylococcal nuclease persistence length

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CCS Chemistry 2019年第1期1卷 138-147页

作者： Linglan Fu Han Wang Hongbin Li Department of Chemistry University of British ColumbiaVancouverBC V6T 1Z1Canada

Mechanochemical coupling cycles underlie the work-generation mechanisms of biological systems and are realized by highly regulated conformational changes of the protein ***,it has been challenging to utilize protein conformational changes to do mechanical work at the macroscopic level in biomaterials,and it remains elusive to con-struct macroscopic mechanochemical devices based on molecular-level mechanochemical coupling ***,the authors demonstrate that protein folding can be utilized to realize protein’s mechano-chemical cycles at both single-molecule and macro-scopic levels.

关键词： protein hydrogel protein folding actu-ation force spectroscopy single molecule