CONSTRUCTION OF 700 MHZ TRIPLE RESONANCE SOLID STATE NMR PROBE

蛋白质结构解析方法的发展 固态NMR光谱学正朝着以下方向发展，即 需要13 C、15 N和1H原子核来分配共振频率。 利用~（15）N和~（15）N之间的相关和自旋交换实验， 肽键中的13 C核有助于顺序分配 蛋白质骨架中固态核磁共振的频率。 的 方法反映了方向解决方案NMR光谱具有 用于分配非常大的蛋白质。 以适应这些 实验中，我们设计并构建了能够 接受三个频率的RF辐射， 元素彼此隔离。 将探针 构造为三重调谐单线圈电感器、电容器（LC） 电路. 陷阱由LC网络构成，旨在隔离 近共振的15 N和13 C射频辐射。 这些探测器是 为550 MHz和360 MHz光谱仪构建。 的 两个光谱仪也进行了修改，以适应三个通道 具有两个可单独调节的功率水平设置的RF辐照 三个原子核中的每一个。 高功率处理滤波器 引入以允许15 N或13 C核的去耦， 观察对方。 三重要求的示范 共振1H到15 N到13 C交叉极化实验证明， 设计的成功。 我们目前正在设计两个， 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.