CONSTRUCTION OF 700 MHZ TRIPLE RESONANCE SOLID STATE NMR PROBE

蛋白质结构解析方法的研究进展 固体核磁共振光谱学正在朝着 需要13C、15N和1H原子核来分配共振频率。 ~(15)N和~(15)N的关联和自旋交换实验 肽键中的13C核促进了顺序分配 蛋白质骨架中的固体核磁共振共振频率。这个 方法是反映核磁共振波谱具有的方向溶液 被用来指认非常大的蛋白质。为了适应这些 实验中，我们设计并构建了能够 接受三个频率的射频辐射，并进行调谐 元素很好地将它们彼此隔离开来。探头是 构造为三调谐单线圈电感、电容(LC) 电路。陷阱是由LC网络构建的，旨在隔离 紧密共振的15N和13C射频辐射。这些探头是 为550兆赫和360兆赫光谱仪建造。这个 还改装了两个光谱仪，以适应三个通道 具有两个单独可调的功率电平设置的射频辐照 对于三个原子核中的每一个。高功率处理过滤器 结合以允许15N或13C核的去耦合，而同时 观察对方。三重要求的论证 1H至15N至13C的共振交叉极化实验证明 设计的成功。我们目前正在设计两个和 需要新硬件的三维实验 这些光谱仪的性能。

The development of the methods to solve protein structures using solid state NMR spectroscopy are progressing toward developments that require 13C, 15N and 1H nuclei to assign the resonance frequencies. The use of correlation and spin exchange experiments between 15N and 13C nuclei in the peptide bonds are facilitating sequential assignment of solid state NMR resonance frequencies in the protein backbone. The methods are reflecting the direction solution NMR spectroscopy has taken to assign very large proteins. To accommodate these experiments, we have designed and constructed NMR probes capable of accepting three frequencies of RF irradiation, with the tuning elements well isolated one from the other. The probes were constructed as triple tuned single coil inductor , capicitor (LC) circuits. Traps were constructed of LC networks designed to isolate the closely resonating 15N and 13C RF irradiations. These probes were constructed for both the 550 Mhz and the 360 MHz spectrometers. The two spectrometers were modified as well to accommodate three channels of RF irradiation with two separately adjustable power level settings for each of the three nuclei. High power handling filters were incorporated to allow decoupling of either 15N or 13C nuclei while observing the other. The demonstration of the demanding triple resonance 1H to 15N to 13C cross-polarization experiments attests to the success of the design. We are currently devising two and three-dimensional experiments that require the new hardware capabilities on these spectrometers.