Phase Transitions in the Higher Order Structure of Giant DNA

巨型 DNA 高阶结构中的相变

• 批准号: 08044069
• 负责人: YOSHIKAWA Kenichi
• 金额: $ 2.18万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08044069/
• 关键词: Single chain observation; Coil-globule transition; First order phase transition; Fluorescence microscopy; Monte Carlo simulation; Long DNA chain; Collapse of DNA; Folding transition; 単分子凝縮; モンテカルロシミュレーション; 単分子備品

As a whole, the international collaboration between Nagoya and Moscow has been performed successfully, including the development on basic concept in polymer physics and also in physical chemistry in mesoscopic system. Through the collaboration, the research group of Nagoya has demonstrated that individual single duplex DNA chains undergoes large discrete phase transition between elongated coil and compacted globule (coil-globule transition), based on the single chain observation by use of fluorescence microscopy, whereas ensemble of DNA has the characteristics of diffuse or continuous transition.From single chain observation, we found this first order phase transition is induced by various kinds of condensation agents such as synthetic polymer, cationic surfactant, low molecular multivalent cation, and alcohol. Based on these experimental findings, active collaboration between Nagoya and Moscow has been performed on the theoretical analysis of the phase transition in a single polymer chain, including Monte Carlo simulation and mean field theory. The essential aspects in the collapsed transition of long DNA chain has been reproduced with these theoretical analysis and calculations. It is to be noted that the existence of the morphological variation in the collapsed products can be interpreted well in these theories.

总体而言，名古屋和莫斯科之间的国际合作进展顺利，包括高分子物理和介观系统物理化学基本概念的发展。通过合作，名古屋研究小组基于荧光显微镜的单链观察，证明了单个双链DNA链在拉长的线圈和压缩的球体之间经历了大的离散相变（线圈-球体转变），而DNA整体具有弥散或连续转变的特征。从单链观察中，我们发现这种一级相变是由多种因素引起的。 合成聚合物、阳离子表面活性剂、低分子多价阳离子、醇等各种缩合剂。基于这些实验结果，名古屋和莫斯科之间积极合作对单聚合物链中的相变进行理论分析，包括蒙特卡罗模拟和平均场理论。通过这些理论分析和计算，再现了长 DNA 链折叠转变的基本方面。值得注意的是，这些理论可以很好地解释塌陷产物中形态变化的存在。

项目成果

Y.Yoshikawa: "Folding and Aggregation of DNA Chains Induced by Complexation with Lipospermine : Formation of a Nuclesome-Like Structure and Network Assembly" FEBS Lett.396. 71-76 (1996)

Y.Yoshikawa：“脂精胺络合诱导的 DNA 链折叠和聚集：类核体结构和网络组装的形成”FEBS Lett.396。

S.G.Starodoubtsev: "Intrachain Setregation in Single Giant DNA Molecules Induced by Poly (2-vinylpyrrolidone)" J.Phys.Chem.100. 19702-19705 (1996)

S.G.Starodoubtsev：“聚 (2-乙烯基吡咯烷酮) 诱导的单个巨型 DNA 分子的链内调整”J.Phys.Chem.100。

M.Ueda: "Stretching of Long DNA under Alternating Current Electric Fields in a Concentrated Polymer Solution" Polym.J.29. 1040-1043 (1997)

M.Ueda：“在浓聚合物溶液中交流电场下长 DNA 的拉伸”Polym.J.29。

N.Emi: ""Gene Transfer Mediated by Polyarginine Requires a Formation of Big Carrier-Complex of DNA Aggregate"" Biochem.Biophys.Res.Commum.Vol.231. 421-424 (1997)

N.Emi：“聚精氨酸介导的基因转移需要形成 DNA 聚集体的大载体复合物”Biochem.Biophys.Res.Commum.Vol.231。

V.V.Vasilevskaya: "Structure of Collapsed Persistent Macromolecule : Toroids vs. Spherical Globule" Biopolymers. 41. 51-60 (1997)

V.V.Vasilevskaya：“塌陷持久性大分子的结构：环形与球状小球”生物聚合物。