The use of proton‐enhanced, natural abundance 13C NMR to study the molecular dynamics of model and biological membranes
The use of proton‐enhanced, natural abundance 13C NMR to study the molecular dynamics of model and biological membranes
复制标题
使用质子增强、自然丰度 13C NMR 研究模型和生物膜的分子动力学
DOI：
10.1016/0014-5793(80)80743-5
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发表时间：
1980
期刊：
影响因子：
3.5
通讯作者：
R. Smith
中科院分区：
文献类型：
--
作者：
B. Cornell;M. Keniry;R. G. Hiller;R. Smith
内在膜蛋白对脂质双层迁移率的影响一直是许多核磁共振（NMR）和电子自旋共振（ESR）研究的主题[1 -6]。使用氮氧探针的早期ESR实验被解释为表明膜内的一些脂质被蛋白质的存在固定化[3]。这一结果随后在许多重构和模型脂质-蛋白质系统中得到证实[3-61]。然而，最近对一系列脂质-蛋白质分散体的氘NMR研究表明，与从纯脂质双层中的相同标记物获得的四极分裂相比，来自具有氘代亚甲基的脂质的四极分裂频率降低[2，7]。这些观察结果已被解释为表明在蛋白质存在下脂质酰基链经历的低频（-10'Hz）运动的幅度增加[2]。有人认为，这种额外的脂质运动的频率是不够快，导致在ESR谱中看到的超高频场分裂的减少。在这里，我们使用天然丰度13 C核的质子增强NMR [8]来研究含有胆固醇、多肽短杆菌肽A的分散体以及来自菠菜叶绿体和牛脑髓鞘的膜制剂中的脂质流动性。
The effect of intrinsic membrane protein on the mobility of lipid bilayers has been the subject of many nuclear magnetic resonance (NMR) and electron spin resonance (ESR) investigations [l-6]. Early ESR experiments employing nitroxide probes were interpreted to show that some of the lipid within the membrane is immobilized by the presence of the protein [3]. This result has been subsequently confirmed in a number of reconstituted and model lipid-protein systems [3-61. Recent deuterium NMR studies of a series of lipid-protein dispersions have shown, however, that the quadrupolar splittings, derived from lipids with deuterated methylene groups, are freq uently reduced compared to those obtained from the same labels in pure lipid bilayers [2, 7]. These observations have been interpreted as indicating an increase in the amplitude of the low frequency (-10’Hz) motion undergone by the lipid acyl chains in the presence of the protein [2]. It is argued that the frequency of this additional lipid motion is insufficiently rapid to cause a reduction in the hyperfme field splittings seen in the ESR spectrum. Here we use proton-enhanced NMR [8] of the natural abundance 13C nuclei to study the lipid mobility in dispersions containing cholesterol, the polypeptide gramicidin A, and in membrane preparations derived from spinach chloroplasts and bovine brain myelin.