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.通过使用固态肽合成仪制备了DP为25 × 10 - 50的单分散PBLG样品。在CHCl_3和DCA混合溶剂中的螺旋-线团转变用~ 1H-NMR和~ 1C-NMR跟踪<13>。这些样品在整个双相区域上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等人先前报告的结果相反。聚天冬氨酸酯所特有的螺旋反转现象已在聚L-天冬氨酸β-对氯苄基酯和聚L-天冬氨酸β-五氟苯乙基酯等体系中进行了研究。在侧链末端的化学修饰被发现引起聚合物的溶解度的明显变化，并且最终螺旋-螺旋转变温度被移动。这些结果表明，参与α-螺旋构象的氢键的稳定性与侧链结构以及周围溶剂的性质敏感地改变。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。