The interaction of water molecules with purple membrane suspension using 2H double‐quantum filter, 1H and 2H diffusion nuclear magnetic resonance
The interaction of water molecules with purple membrane suspension using 2H double‐quantum filter, 1H and 2H diffusion nuclear magnetic resonance
复制标题
使用 2H 双量子滤波器、1H 和 2H 扩散核磁共振观察水分子与紫色膜悬浮液的相互作用
作者：
L. Frish;N. Friedman;M. Sheves;Y. Cohen
细菌视紫红质是盐盐杆菌紫色膜（PM）的一种膜蛋白，它被分离为高度组织化的二维六边形微晶体片，水分子在影响其质子泵功能方面起着至关重要的作用。在本文中，我们使用单量子和双量子2H核磁共振以及1H和2H扩散核磁共振来表征D2O悬浮液中水分子与PM的相互作用。我们发现，在浓PM样品（0.61 mM）上的强磁场影响下，PM片会影响整个水种群，并且在D2O分子中观察到残留的四极分裂（ν q ~ 5.5 Hz, 298 K, 11.7 T）。我们发现残余四极耦合、获得最大DQF信号的产生时间（τmax）和PM样品中水分子的2H DQF谱的相对强度（此处称为核磁共振序参数）对PM的温度、稀释和化学修饰非常敏感。在D2O浓PM样品中，这些核磁共振参数似乎反映了PM的相对组织。有趣的是，我们观察到这些参数中的一些对三聚体填充效率很敏感，这是由载o膜行为得出的结论。离子化蓝膜、部分脱水样品和洗涤剂处理PM的数据表明，这些与磁场相关的D2O NMR序参量对PM的结构完整性很敏感。此外，我们发现在核磁共振磁体内外加热PM样品，冷却后，对浓缩PM悬浮液中水分子的核磁共振特性有不同的影响。在有强磁场和无强磁场条件下加热和冷却PM样品的D2O核磁共振有序参数的差异，证实了上述D2O有序参数是PM样品微观和宏观有序的间接反映。此外，1H NMR扩散测量表明，根据它们的扩散系数，至少可以识别出三种不同的水种群。这些水种群似乎与先前报道的PM系统的不同水种群有关。©2004 Wiley期刊公司生物聚合物,2004
Bacteriorhodopsin is a membrane protein of the purple membrane (PM) of Halobacterium salinarum, which is isolated as sheets of highly organized two‐dimensional hexagonal microcrystals and for which water molecules play a crucial role that affects its function as a proton pump. In this paper we used single‐ and double‐quantum 2H NMR as well as 1H and 2H diffusion NMR to characterize the interaction of water molecules with the PM in D2O suspensions. We found that, under the influence of a strong magnetic field on a concentrated PM sample (0.61 mM), the PM sheets affect the entire water population and a residual quadrupolar splitting (υq ∼5.5 Hz, 298 K, at 11.7 T) is observed for the D2O molecules. We found that the residual quadrupolar coupling, the creation time in which a maximal DQF signal was obtained (τmax), and the relative intensity of the 2H DQF spectrum of the water molecules in the PM samples (referred to herein as NMR order parameters) are very sensitive to temperature, dilution, and chemical modifications of the PM. In concentrated PM samples in D2O, these NMR parameters seem to reflect the relative organization of the PM. Interestingly, we have observed that some of these parameters are sensitive to the efficiency of the trimer packing, as concluded from the apo‐membrane behavior. The data for dionized blue membrane, partially delipidated sample, and detergent‐treated PM show that these D2O NMR order parameters, which are magnetic field dependent, are sensitive to the structural integrity of the PM. In addition, we revealed that heating the PM sample inside or outside the NMR magnet has, after cooling, a different effect on the NMR characteristics of the water molecules in the concentrated PM suspensions. The difference in the D2O NMR order parameters for the PM samples, which were heated and cooled in the presence and in the absence of a strong magnetic field, corroborates the conclusions that the above D2O order parameters are indirect reflections of both microscopic and macroscopic order of the PM samples. In addition, 1H NMR diffusion measurements showed that at least three distinct water populations could be identified, based on their diffusion coefficients. These water populations seem to correlate with different water populations previously reported for the PM system. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
登录
查看更多内容
DOI：
10.1073/pnas.79.2.403
发表时间：
1982-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
BRAIMAN, M;MATHIES, R
通讯作者：
MATHIES, R
影响因子：
2.9
作者：
Steven O. Smith;§. Huub;J. M. D. Groot;R. Gebhard;IIJacques M. L. Courtin;J. Lugtenburg;Judith Herzfeld;R. G. Griffin
通讯作者：
Steven O. Smith;§. Huub;J. M. D. Groot;R. Gebhard;IIJacques M. L. Courtin;J. Lugtenburg;Judith Herzfeld;R. G. Griffin
影响因子：
56.9
作者：
Luecke, H;Richter, HT;Lanyi, JK
通讯作者：
Lanyi, JK
影响因子：
5.6
作者：
Luecke, H;Schobert, B;Lanyi, JK
通讯作者：
Lanyi, JK
脂质表面电荷对细菌视紫红质从紫色到蓝色转变的影响。
DOI：
10.1073/pnas.84.11.3681
发表时间：
1987
影响因子：
11.1
作者：
Szundi,I;Stoeckenius,W
通讯作者：
Stoeckenius,W