在SH3域的折叠和展开状态中的缓慢动态
M Tollinger1, N R Skrynnikov, F A Mulder
1Structural Biology and Biochemistry Program, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.
Journal of the American Chemical Society
|November 15, 2001
概括
核磁共振 (NMR) 研究显示,Drosophila drk N-终端SH3域经历了缓慢的折叠/展开交换. 这项研究提供了对未展开的蛋白质状态内的结构动态的洞察.
科学领域:
- 蛋白质动力学和结构生物学
- 生物物理化学 生物物理化学
- 核磁共振 (NMR) 谱学是指核磁共振的光谱学.
背景情况:
- 果的drk N-终端SH3域 (drkN SH3) 对于信号传导至关重要.
- 了解蛋白质结构动力学是阐明生物功能的关键.
- 蛋白质可以存在于多个结构状态,影响它们的相互作用和活性.
研究的目的:
- 在drkN SH3域中研究微秒到秒的时间尺度交换过程.
- 分析折叠和展开状态中的构造交换.
- 描述蛋白质折叠/展开过渡的自由能量场景.
主要方法:
- 利用15N放松分散实验来探测动态过程.
- 应用基于卡尔-普尔塞尔-梅布姆-吉尔 (CPMG) 的测量方法来分析汇率.
- 结合放松分散数据与15N个纵向放松实验进行汇率解卷.
主要成果:
- 在20°C时,drkN SH3域存在于折叠 (F(exch)) 和展开 (U(exch)) 状态之间的2:1平衡.
- 在NMR化学转移时间表上观察到缓慢的交换 (k(ex) = 2.2 s−1.
- 在未折叠状态内确定了局部的,非本土的疏水性崩,表现出微秒/毫秒时间尺度动态.
结论:
- 放松分散实验对于研究未折叠的蛋白质状态中的构造交换非常敏感.
- 该研究提供了一种方法来获取蛋白质系统的自由能量格局的信息.
- 使用CPMG实验开发了一种一般适用的分析表达式,用于分析慢交换极限中的两态交换.
相关概念视频
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Protein Structure Is Critical to Its Biological Function
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Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...


