Role of Hydrogen Bond in Polypeptides - ^2HNMR Studies in the Lyotropic Liquid Crystalline State

氢键在多肽中的作用 - 溶致液晶态的 ^2HNMR 研究

• 批准号: 13650959
• 负责人: ABE Akihiro
• 金额: $ 2.3万
• 依托单位: TOKYO INSTITUTE OF POLYTECHNICS
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650959/
• 关键词: Poly(L-glutamate); Poly(L-aspartate); Helix-Coil Transition; Monodisperse PBLG; Re-entrant Isopropic Phase; Intramolecular Hydrogen Bond; Helix Sense Inversion; Chemical Modification of Side Chain Terminals; ペンタフルオロフェネチル基の導入; らせんセンスの反転; ヘリックス-コイ

1. Monodisperse PBLG samples having DP of 25 〜 50 have been prepared by using a solid-state peptide synthesizer. The helix-coil transitions in a mixed solvent comprising CHCl_3 and DCA were followed by ^1H- and ^<13>C-NMR. These samples exhibited two separate chemical shifts over the entire biphasic region : one from the helical and the other from the coil part. These observations are in contraditoin to those previously reported by Nagayame et al.2. The helix-sense inversion phenomena peculiar to poly(aspartic acid ester)s has been studies for systems such as poly (β-p-chlorobenzyl L-aspartate) and poly(β-pentafluorophenethyl L-aspartate). Chemical modifications at the sidechain terminal were found to cause appreciable changes in the solubility of polymers, and eventually the helix-helix transition temperatures were shifted. These results indicate that the stability of hydrogen bonds involved in the α-helix conformation sensitively alters with the sidechain structure as well as the character of the surrounding solvents. Further investigations are underway to elucidate these unique characteristics of the internal hydrogen-bonds.

1.利用固相法合成了聚合度为25~50的单分散PBLG样品。在由CHCl_3和DCA组成的混合溶剂中，螺旋-线圈转变之后是^1H和^&lt；13&gt；C-核磁共振。这些样品在整个两相区域表现出两个独立的化学位移：一个来自螺旋部分，另一个来自线圈部分。这些观察结果与Nagayame等人以前报告的结果相反。本文研究了聚(β-对氯苄基L-天冬氨酸)和聚(β-五氟苯乙基L-天冬氨酸)等体系中聚天冬氨酸酯所特有的螺旋反转现象。侧链末端的化学修饰导致聚合物的溶解度发生显著变化，最终螺旋-螺旋转变温度发生了变化。这些结果表明，α-螺旋构象中涉及的氢键的稳定性随侧链结构以及周围溶剂的性质而敏感地改变。进一步的研究正在进行中，以阐明内部氢键的这些独特特征。

项目成果

H.Furuya: "Nematic Conformation of Oxyethylene Spacers Involved in Main-Chain Liquid Crystals"Macromol. Symp.. 192. 239-250 (2003)

H.Furuya：“主链液晶中涉及的氧乙烯间隔基的向列构象”Macromol。

A.Abe: "A Critical Study of the Entropy-Volume Relation of Chain Molecules in the Fluid State -Computer Simulation of n-Undecane and Comparison with Experimental PVT Data"Macromolecules. 34. 6450-6455 (2001)

A.Abe：“流体状态下链状分子的熵-体积关系的批判性研究 - 正十一烷的计算机模拟以及与实验 PVT 数据的比较”大分子。

A. Ushiyama, H. Furuya, A. Abe, T. Yamazaki: "The Mechanism of the Helix-Sense Inversion of Polyaspartates as Revealed by the Study of Model Block Copolymers"Polym. J.. Vol. 34. 450-454 (2002)

A. Ushiyama、H. Furuya、A. Abe、T. Yamazaki：“模型嵌段共聚物研究揭示的聚天冬氨酸螺旋反转机制”

A.Abe: "Thermodynamics of Polymeric Fluids : Effect of Volume on the Configurational Entropy of Chain Molecules"Macromol. Symp.. 174. 383-391 (2001)

A.Abe：“聚合物流体的热力学：体积对链分子构型熵的影响”Macromol。

A.Abe: "The Order-Disorder of Polymeric Chains and Thermodynamic Significance"Rep. Prog. Polym. Phys. Jpn.. 43. 21-42 (2001)

A.Abe：“聚合物链的有序无序和热力学意义”Rep。