化学学报 ›› 1992, Vol. 50 ›› Issue (3): 281-287. 上一篇    下一篇

研究论文

胃泌素有关肽溶液构象的2D-NMR研究

孙红哲;邵伟平;唐雯霞;王新昌   

  1. 南京大学配位化学国家重点实验室;南京大学生物化学系
  • 出版日期:1992-03-15 发布日期:1992-03-15

The study of conformations in solution for gastrin with 2D NMR

SUN HONGZHE;SHAO WEIPING;TANG WENXIA;WANG XINCHANG   

  • Online:1992-03-15 Published:1992-03-15

用2D NMR深入研究了五肽、四肽胃泌素在 DMSO 中的构象。利用 COSY 谱、Relayed-COSY 谱、DQF-J 分解谱和 NOESY 谱归属了全部共振峰。计算了肽键平面的Φ角、旋转异构体分布和旋转异构体之间自由能差。根据 NOESY 谱得到了距离约束条件。结合Φ角及旋转异构体分布, 推导出五肽胃泌素分子的构象膜型。结果表明, 五肽、四肽胃泌素在 DMSO 中以半角构象存在, 在其主要的旋转异构体中 Trp 的吲哚环和 Met 的 S 原子具有类似5,1-benzothiazocine 三维结构, 可能是具有生物活性的原因。

关键词: 寡肽, 构象, 热带林, 二维核磁共振谱法, 四肽, 胃泌素, 五肽, 溶液构象, DMSO, COSY谱

Conformations of Boc-pentapeptide (Boc-b-Ala-Trp-Met-Asp-PheNH2) and Boc-tetrapeptide (Boc-Trp-Met-Asp-PheNH2) of gastrin in DMSO solns. were investigated by 2-dimensional (2D) NMR spectrometry. 2D COSY, Relayed-COSY, DQF-J Resolved Spectroscopy and NOESY were applied to assign all resonance lines completely, F dihedral angles, rotamer populations, and their energy differences were calculated According to NOE, conditions of distance constraints were obtained. Taken together with F and rotamer populations, the model of conformation for Boc-pentapeptide was obtained. Conformations of Boc-pentapeptide and Boc-tetrapeptide are characterized by half turn in DMSO solution In their main rotamers, indole of Trp and S atom of Met form a 3-dimensional structure similar to 5,1-benzothiazocine, and this structure may be the cause of biol. potency.

Key words: OLIGOPEPTIDE, CONFORMATION, TROPICAL FOREST, 2D NMR SPECTROMETRY, GASTRIN, PENTAPEPTIDE

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