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已成功进行，包括在聚合物物理学基本概念以及介观系统中的物理化学方面的发展。通过合作，Nagoya的研究小组表明，基于单个链的观察，基于荧光显微镜的单个链观测，单个单一的双工DNA链在伸长的线圈和紧凑的球（线圈 - 盘子过渡）之间进行了大量的离散相变（COIL-GLOBULE TRUXITION），而DNA的各种dna的序列均具有循环序列。诸如合成聚合物，阳离子表面活性剂，低分子多价阳离子和酒精之类的冷凝剂。基于这些实验发现，Nagoya和莫斯科之间的主动协作已在单个聚合物链中的相变的理论分析（包括蒙特卡洛模拟和平均场理论）上进行了。通过这些理论分析和计算，已经重现了长DNA链折叠过渡的基本方面。应当指出的是，在这些理论中可以很好地解释崩溃产品中形态学变化的存在。

项目成果

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。

K.Yoshikawa: ""Nucleation and Growth in Single DNA Molecules"" J.Am.Chem.Soc.Vol.118. 929-930 (1996)

K.Yoshikawa：““单个 DNA 分子的成核和生长””J.Am.Chem.Soc.Vol.118。

S.M.Mel'nikov: ""Cooperation between salt induced globule-coil transition in single duplex DNA complexed with cationic surfactant and sphere-rod transition of surfactant micelles"" Progr.Colloid.Polym.Sci.Vol.106. 209-214 (1997)

S.M.Melnikov：“盐诱导的单双链 DNA 与阳离子表面活性剂复合的球-螺旋转变与表面活性剂胶束的球-杆转变之间的合作””Progr.Colloid.Polym.Sci.Vol.106。

H.Noguchi: ""First-order phase transition in a stiff polymer chain"" Chem.Phys.Lett.Vol.278. 184-188 (1997)

H.Noguchi：“刚性聚合物链中的一级相变”Chem.Phys.Lett.Vol.278。