A SOLID STATE NMR INVESTIGATION OF BACTERIORHODOPSIN

所提出的研究的目的是演示方法分配化学位移和位移各向异性均匀标记的膜蛋白在固态。这是一个具有挑战性的项目，然而，没有均匀的13 C，15 N标记的蛋白质，甚至中等大小的蛋白质尚未完全分配在固态。核磁共振方法（脉冲序列，硬件）已经有了显着的改进，这表明这是一种可能性。特别是，偶极再耦合技术与更高的效率，先进的去耦方法，探针能够25-30 kHz MAS和200 kHz的去耦场，和1H频率为750 MHz的宽孔磁铁应导致全固态NMR膜蛋白的结构测定。考虑到侧链和视黄醇之间的显著相互作用，分析视黄醇结合口袋中的化学位移将特别有趣。这些位移将与量子化学方法一起沿着用于详细分析质子单轴泵浦的机制。

The objective of the proposed research is to demonstrate methods to assign chemical shifts and shift anisotrophies on uniformly labeled membrane proteins in the solid state. This is a challenging project however, no uniformly 13C, 15N labeled protein of even moderate size has yet been fully assigned in the solid state. There have been significant improvements in NMR methodology (pulse sequence, hardware) which point to this as a possibility. In particular, dipolar recoupling techniques with higher efficiencies, advanced decoupling methods, probes capable of 25-30 kHz MAS and 200 kHz decoupling fields, and widebore magnets with 1H frequencies of 750 MHz should lead to full sold-state NMR structure determinations of membrane proteins. The chemical shifts in the retinal binding pocket will be particularly interesting to analyze, given the significant interactions between the sidechains and retinal. These shifts will be used along with quantum chemical methods to analyze in detail the mechanism by which the proton is pumped uniaxially.