沉积溶液的动态核两极化
Enrico Ravera1, Björn Corzilius, Vladimir K Michaelis
1Department of Chemistry Ugo Schiff and Magnetic Resonance Center (CERM), University of Florence, 50019 Sesto Fiorentino (FI), Italy.
Journal of the American Chemical Society
|January 22, 2013
概括
沉积溶液动态核极化 (SedDNP) 在没有玻璃形成者的蛋白质样本上实现了高DNP增强. 这种方法为DNP实验提供了一种新的样本准备技术.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 磁共振光谱学 磁共振光谱学
背景情况:
- 动态核极化 (DNP) 通过将极化从未配对的电子转移到原子核来增强NMR灵敏度.
- 传统的DNP样品制备通常依赖于玻璃形成剂,如糖醇,这可能使分析复杂化.
- 阿波费里丁 (ApoF) 是480kDa的铁储存蛋白质,作为研究基于蛋白质的DNP的模型系统.
研究的目的:
- 通过沉积蛋白质样本,研究使用沉积蛋白质样本实现显著DNP增强的可行性.
- 探索一种新的样品制备方法,沉积溶液DNP (SedDNP),用于DNP增强的NMR光谱.
- 为了比较SedDNP与传统DNP样品制备方法的有效性.
主要方法:
- 在没有玻璃形成剂的情况下,阿波费里丁 (ApoF) 与双基极化剂共同沉积.
- 动态核极化 (DNP) 实验在5 T和低于90 K的温度下进行.
- 从SedDNP获得的DNP增强因子 (ε) 与甘醇悬浮样本的DNP增强因子 (ε) 的比较.
主要成果:
- 对于沉积的阿波费里丁样本,SedDNP产生了相当大的DNP增强因子 (ε > 40).
- 蛋白质沉积物状态表现出"玻璃状"的特性,在结时有效地分散了比基极化剂.
- 相比之下,冷的ApoF水溶液导致DNP增强显著降低 (ε ≈2).
结论:
- 蛋白质的沉积状态可以在功能上被描述为"微晶玻璃",适合DNP.
- SedDNP提供了一种新的有效方法,用于为DNP增强的NMR光谱学准备样本.
- 这种方法可以避免使用传统的玻璃成型剂,从而可能简化样品的处理和分析.
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