固体核磁共振中膜蛋白双交叉极化效率与动力学参数相关的定量分析

发布时间：2018-04-09 02:07

本文选题：固体核磁共振(NMR)　切入点：魔角旋转(MAS)　出处：《波谱学杂志》2017年03期

【摘要】：固体核磁共振(NMR)中双交叉极化(DCP)是用于膜蛋白信号指认的多维异核相关实验的基本技术模块.DCP的效率在很大程度上决定了多维异核相关实验的效率.本文分析了3种典型的膜环境中的膜蛋白(AQPZ、DAGK和EV71 2B)的DCP效率及其影响因素.结果显示,在相同的实验条件下,3种蛋白样品的DCP效率存在明显差异:其中AQPZ的DCP效率最高(31%),DAGK的效率次之(23%),EV71 2B的效率最低(14%).通过测量它们在旋转坐标下的自旋-晶格弛豫时间(T_(1ρ))和偶极耦合常数(DHN),发现膜蛋白的运动会明显缩短T_(1ρ),但对DHN的影响较小.在实验的基础上,建立了T_(1ρ)与DCP效率相关的模型,并基于DCP动力学的定量分析,证明了运动导致的T_(1ρ)缩短是降低DCP效率的主要原因.因此,可以通过定量分析未知样品的T_(1ρ)来预测其DCP的最优效率,为DCP实验的优化提供依据.
[Abstract]:The efficiency of dual-cross-polarization DCPs in solid-state nuclear magnetic resonance imaging (SNMR) is the basic technology module of multi-dimensional heteronuclear correlation experiment for the identification of membrane protein signal. The efficiency of DCP determines the efficiency of multi-dimensional heteronuclear correlation experiment to a great extent.The DCP efficiency of AQPZDAGK and EV71 2B in three typical membrane environments and its influencing factors were analyzed.The results showed that there were significant differences in DCP efficiency among the three protein samples under the same experimental conditions: the DCP efficiency of AQPZ was the highest and that of DAGK was 31and the second was the lowest efficiency of EV712B.By measuring the spin-lattice relaxation time and the dipole coupling constant of T _ S _ 1 蟻 _ (1) and the dipole coupling constant, it is found that the membrane protein activity shortens the T _ S _ 1 蟻 _ (1), but has little effect on the DHN.Based on the experimental results, the model of DCP efficiency is established. Based on the quantitative analysis of DCP dynamics, it is proved that the main reason for reducing the efficiency of DCP is the shortening of DCP caused by exercise.Therefore, the optimal efficiency of DCP can be predicted by quantitative analysis of the unknown sample, which provides the basis for the optimization of the DCP experiment.
【作者单位】：波谱与原子分子物理国家重点实验室武汉磁共振中心(中国科学院武汉物理与数学研究所);中国科学院大学;
【基金】：国家自然科学基金资助项目(10675162)
【分类号】：O482.532

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