DIPOLAR CORRELATION NMR-SPECTROSCOPY OF A MEMBRANE-PROTEIN
DIPOLAR CORRELATION NMR-SPECTROSCOPY OF A MEMBRANE-PROTEIN
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DOI：
10.1021/ja00101a042
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发表时间：
1994-11-02
影响因子：
15
通讯作者：
GRIFFIN, RG
中科院分区：
文献类型：
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作者：
GRIFFITHS, JM;LAKSHMI, KV;GRIFFIN, RG
我们演示了新的核磁共振实验——射频驱动重耦合 (RFDR)——在旋转固体中建立空间连通性和测量核间距离的应用。 RFDR 在纵向混合方案中采用转子同步 pi 脉冲，将偶极耦合重新引入魔角旋转 (MAS) NMR 实验中。我们利用这种技术测量了多晶 D,L-丙氨酸中 0.25 nm 的距离，并确定了整合膜蛋白细菌视紫红质 (bR) 中的相对距离。在后一种情况下，我们重点关注核间距离，该距离定义了组成暗适应 bR 的两个构象异构体中视网膜蛋白希夫碱键的构型。我们的结果表明，RFDR 是一种有效且实用的固体结构研究技术，包括分子量高达 85 kDa 的生物分子。
We demonstrate the application of a new NMR experiment-RF-driven recoupling (RFDR)-for establishing spatial connectivities and measuring internuclear distances in spinning solids. RFDR employs rotor-synchronized pi-pulses in a longitudinal mixing scheme to reintroduce dipolar couplings into magic angle spinning (MAS) NMR experiments. We have utilized this technique to measure a 0.25 nm distance in polycrystalline D,L-alanine and to determine relative distances in the integral membrane protein bacteriorhodopsin (bR). In the latter case, we have focused on an internuclear distance that defines the configuration about the retinal-protein Schiff base linkage in the two conformers comprising dark-adapted bR. Our results demonstrate that RFDR is a valid and practical technique for structural investigations of solids including biological molecules with molecular weights as great as 85 kDa.