用dHis-Cu2+ (NTA) 基因在脉冲双极EPR光谱学中区分标签和蛋白质符合者
Caspar A Heubach1, Zikri Hasanbasri2, Dinar Abdullin1
1Clausius-Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany.
Chemistry (Weinheim an der Bergstrasse, Germany)
|September 27, 2023
概括
一个硬的旋转标签,铜II-酸结合两个histidines (dHis-Cu2+NTA),揭示了Yersinia外蛋白O (YopO) 的单个构造,使用脉冲双极EPR光谱 (PDS). 这种方法简化了结构生物学分析.
科学领域:
- 结构生物学 结构生物学
- 生物物理学的生物物理.
- 频谱学是一种光谱学.
背景情况:
- 脉冲双极EPR光谱 (PDS) 具有位点定向的旋转标记对于结构生物学至关重要.
- 具有灵活链接器的传统旋转标签使距离分布和生物分子构造的解释变得复杂.
- 一个刚性旋转标签,铜II-酸结合两个histidines (dHis-Cu2+NTA),提供了改进的精度.
研究的目的:
- 调查Yersinia外蛋白O (YopO) 中的双模距离分布是否来自多种蛋白质构造或灵活的旋转标签.
- 评估用于PDS分析的刚性dHis-Cu2+ (NTA) 旋转标签的实用性.
- 为了确定dHis-Cu2+(NTA) 结合在本地histidines的存在中的特异性.
主要方法:
- 使用刚性dHis-Cu2+(NTA) 图案进行位点定向的旋转标签.
- 脉冲双极EPR光谱 (PDS) 实验,包括脉冲电子-电子双共振 (PELDOR/DEER) 和放松诱导的双极调制增强 (RIDME).
- 从用dHis-Cu2+(NTA标记的YopO获得的距离分布的分析).
主要成果:
- 使用dHis-Cu2+(NTA) 标签的PDS实验 (PELDOR/DEER和RIDME) 给出了YopO的单模距离分布.
- 这表明,YopO的α-螺旋脊柱存在于冷溶液中的单一形状.
- 在dHis-Cu2+ (NTA) 标签上,即使与22种竞争的本土胺,也显示了针对双胺位点的优先结合.
结论:
- 刚性的dHis-Cu2+ (NTA) 旋转标签提供了狭窄的距离分布,促进了结构生物学中准确的结构分析.
- 在研究条件下,YopO蛋白采用单一的形状.
- 这种dHis-Cu2+ (NTA) 标签策略是有效的,不需要histidine-null背景.
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