使用HSQC和HMQC实验重建"隐形"激发蛋白质状态的NMR光谱
Nikolai R Skrynnikov1, Frederick W Dahlquist, Lewis E Kay
1Protein Engineering Network Center of Excellence, Department of Medical Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8. nikolai@purdue.edu
Journal of the American Chemical Society
|October 10, 2002
概括
卡尔-普尔塞尔-梅布姆-吉尔 (CPMG) 放松测量显示了毫秒时间尺度的化学交换动态. 一种新的方法确定了化学转移差异的标志,这对于理解蛋白质构造变化至关重要.
科学领域:
- 生物物理化学 生物物理化学
- 结构生物学 结构生物学
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
背景情况:
- 卡尔-普尔塞尔-梅布姆-吉尔 (CPMG) 放松分散对于研究毫秒时间尺度的化学交换至关重要.
- 在CPMG的实验中,我们得出了相互转换率,种群和化学转移差异.
- 在标准的CPMG实验中,不能直接得到Δω的符号.
研究的目的:
- 开发一种方法来确定交换系统中化学转移差异的标志.
- 增强从CPMG放松分散研究中获得的信息.
- 将该方法应用于表现为 conformational 交换的蛋白质系统.
主要方法:
- 使用可变脉冲间隔的卡尔-普尔塞尔-梅布姆-吉尔 (CPMG) 放松测量.
- 在不同的磁场下,对比HSQC光谱间接维度的化学变化.
- 将HSQC和HMQC光谱组合在一个单一场地,以确定Δω的标志.
- 将该方法应用于T4溶酶腔突变 (L99A).
主要成果:
- 成功确定了除绝对值外的化学转移差异 (Δω) 的标志.
- 在T4溶酶L99A突变体中表现出毫秒时间尺度的形状交换.
- 量化了汇率在25°C时大约为1450s-1的汇率.
结论:
- 开发的方法可靠地提供化学转移差异的信号,补充CPMG数据.
- 这种方法显著推进了生物巨分子中的动态过程的表征.
- 精确确定交换参数有助于理解蛋白质的功能和动态.
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