Spin Saturation Transfer Difference NMR (SSTD NMR): A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes.
Spin Saturation Transfer Difference NMR (SSTD NMR): A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes.
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DOI：
10.3791/54499
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发表时间：
2016-11-12
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影响因子：
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通讯作者：
Muñoz MP
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文献类型：
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作者：
Quirós MT;Macdonald C;Angulo J;Muñoz MP
这个详细的协议描述了新的自旋饱和转移差核磁共振协议（SSTD NMR），最近在我们的小组开发的研究过程中的相互网站的化学交换，是难以分析的传统方法。顾名思义，该方法结合了用于小分子的自旋饱和转移方法和用于研究蛋白质-配体相互作用的饱和转移差（STD）NMR方法，通过测量经历化学交换的小有机和有机金属分子中沿着增加的饱和时间（累积曲线）的瞬时自旋饱和转移。与现有方法相比，该方法的优点是：不需要达到交换信号的合并;只要分离交换位点的一个信号就可以应用该方法;不需要测量T1或达到稳态饱和;直接测量速率常数值，并且仅使用一组实验在同一实验中获得T1值。为了验证该方法，我们研究了N，N-二甲基酰胺的受阻旋转动力学，其中有很多数据可供比较。使用SSTD获得的热力学参数与已报道的参数（自旋饱和转移技术和线形分析）非常相似。该方法可以应用于更具有挑战性的基板，不能通过以前的方法进行研究。我们设想，简单的实验设置和广泛适用的方法，以各种各样的基板将使这成为一个共同的技术之间的有机和有机金属化学家没有广泛的专业知识，在NMR。
This detailed protocol describes the new Spin Saturation Transfer Difference Nuclear Magnetic Resonance protocol (SSTD NMR), recently developed in our group to study processes of mutual-site chemical exchange that are difficult to analyze by traditional methods. As the name suggests, this method combines the Spin Saturation Transfer method used for small molecules, with the Saturation Transfer Difference (STD) NMR method employed for the study of protein-ligand interactions, by measuring transient spin saturation transfer along increasing saturation times (build-up curves) in small organic and organometallic molecules undergoing chemical exchange. Advantages of this method over existing ones are: there is no need to reach coalescence of the exchanging signals; the method can be applied as long as one signal of the exchanging sites is isolated; there is no need to measure T1 or reach steady state saturation; rate constant values are measured directly, and T1 values are obtained in the same experiment, using only one set of experiments. To test the method, we have studied the dynamics of the hindered rotation of N,N-dimethylamides, for which much data is available for comparison. The thermodynamic parameters obtained using SSTD are very similar to the reported ones (spin-saturation transfer techniques and line-shape analysis). The method can be applied to more challenging substrates that cannot be studied by previous methods. We envisage that the simple experimental set up and the wide applicability of the method to a great variety of substrates will make this a common technique amongst organic and organometallic chemists without extensive expertise in NMR.