Formation of Nano-Ordered Structure through Folding Transition of Single Polymer Chain

通过单链聚合物链的折叠转变形成纳米有序结构

• 批准号: 10450365
• 负责人: YOSHIKAWA Kenichi
• 金额: $ 8.32万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10450365/
• 关键词: Giant DNA; Folding Transition; Single Molecule Observation; Fluorescence Microscopy; DNA Condensation; Disorder-Order Transition; Phase Diagram of Single Chain; Laser Trapping; コイルーグロビュール転移; 単分子観察; 温度依存性; 蛍光顕微鏡; ポリアミン; 潜熱; ボルツマン分布

We have performed a systematic study on the folding transition of single polymer chains both from experiment and theory.(1) From numerical simulations of Monte Carlo and molecular dynamics, the phase-diagram of a single polymer has been deduced. In general, the transition is discerete for the change from elongated coil into order compact structure, i.e., discorder-order transition. Whereas, the transition is continuos from elongated coil into liquid-like globule state ; i.e., disorder-disorder transition.(2) Experimental method to observe the structural transition on individual DNA chains has been established. It was found that, in the presence of polycation, DNA undergoes folding transition from elongated the compact state with increase of temperature. Contrary this, DNA chains exhibit unfolding transition in PEG-solution with increase of temperature.(3) We have constructed an experimental system to trap individual DNA chains by IR laser. It was found that individual DNA molecules are transferred selectively as long as centimeter in aqueous solution. As an extension of such study, we have succeeded in observing rhythmic change between clongated and compact states in single DNA chains under suitable nonequilibrium condition.

我们从实验和理论两方面对高分子单链的折叠转变进行了系统的研究。(1)通过Monte Carlo和分子动力学的数值模拟，推导出了单一聚合物的相图。通常，对于从细长线圈到有序紧凑结构的变化，即，无序转变然而，从拉长的线圈到液体状小球状态的转变是连续的;即，无序-无序转变(2)建立了观察单个DNA链结构转变的实验方法。结果表明，在聚阳离子存在下，随着温度的升高，DNA的折叠状态发生了从伸长到致密的转变。与此相反，DNA链在PEG溶液中随着温度的升高表现出去折叠转变。(3)我们建立了一个用红外激光捕获单个DNA链的实验系统。发现单个DNA分子在水溶液中选择性转移长达厘米。作为这一研究的延伸，我们在适当的非平衡条件下，成功地观察到了单链DNA分子在凝聚态和紧密态之间的节律性变化。

项目成果

Yu.S.Velichko: "Effect of Twisting on the Behavior of a Double-Stranded Polymer Chain : A Monte Carlo Simulation"J.Chem. Phys.. 111. 9424-9433 (1999)

Yu.S.Velichko：“扭转对双链聚合物链行为的影响：蒙特卡罗模拟”J.Chem。

H.Murayama: "Thermodynamics of the Collapsing Phase Transition in a Single Duplex DNA Molecule"J. Phys. Chem.. B103. 10517-10523 (1999)

H.Murayama：“单个双链 DNA 分子中塌缩相变的热力学”J。

Y.Matsuzawa: "Visualization and Optical Trapping of an Individual Submicrometer-Sized Assembly in Aqueous Solution : Aminated Polyethylene Glycol (PEG-A) Complexed with Palmitic"J.Am.Chem.Soc. 122. 2200-2205 (2000)

Y.Matsuzawa：“水溶液中单个亚微米尺寸组装体的可视化和光学捕获：胺化聚乙二醇 (PEG-A) 与棕榈酸复合”J.Am.Chem.Soc。

Y.Matsuzawa: "Visualization and Optical Trapping of an Individual Submicrometer-Sized Assembly Aqueous Solution : Aminated Polyethylene Glycol (PEG-A) Complexed with Palmitic Acid and DNA in Poly (ethylene glycol)(PEG) Solution"J.Am.Chem.Soc.. 122. 2200-2

Y.Matsuzawa：“单个亚微米尺寸组装水溶液的可视化和光学捕获：胺化聚乙二醇 (PEG-A) 与棕榈酸和 DNA 在聚乙二醇 (PEG) 溶液中复合”J.Am.Chem。

S.Kidaki: "Folding and unfolding of a giant duplex-DNA ina mixed solution with polycations,polyanions and crowding neutral polymers" Biophys.Chem.109. 133-143 (1998)

S.Kidaki：“在聚阳离子、聚阴离子和拥挤中性聚合物的混合溶液中折叠和展开巨型双链 DNA”Biophys.Chem.109。