CHARACTERIZATION OF MAGNETICALLY ORIENTABLE BILAYERS IN MIXTURES OF DIHEXANOYLPHOSPHATIDYLCHOLINE AND DIMYRISTOYLPHOSPHATIDYLCHOLINE BY SOLID-STATE NMR
CHARACTERIZATION OF MAGNETICALLY ORIENTABLE BILAYERS IN MIXTURES OF DIHEXANOYLPHOSPHATIDYLCHOLINE AND DIMYRISTOYLPHOSPHATIDYLCHOLINE BY SOLID-STATE NMR
复制标题
DOI：
10.1021/bi00152a029
复制
发表时间：
1992-09-22
期刊：
影响因子：
2.9
通讯作者：
SCHWONEK, JP
中科院分区：
文献类型：
--
作者：
SANDERS, CR;SCHWONEK, JP
用多核（C-13，P-31，H-2）固体核磁共振对长链和短链磷脂酰胆碱（PC）的混合物进行了表征。这项工作的补充和扩展以前的表征，这种混合物的集中在温度高于凝胶液晶相转变温度（T（m））的长链PC组件的混合物。在T（m）以上，观察到高度取向的双层样组装体可以由二肉豆蔻酰磷脂酰胆碱（DMPC）和二己酰磷脂酰胆碱（DHPC）的混合物形成，摩尔比范围约为1：3.5至1：2（DHPC：DMPC）在相当大的脂质浓度范围内（对于1：2.5的样品，至少3-40% w/v总脂质）。观察到取向仅发生在L（α）样相中。NMR数据可以通过DHPC-DMPC聚集体的一般模型来解释，其中DHPC可以在两个不同的群体中发现（一个高度有序，一个不是）。的甘油主链/头基区域的长链和短链PC组成的组件的平均构象进行判断，通过固态C-13 NMR是彼此相似的。收集到的信息，这些混合物和质量的定向NMR光谱表明，DHPC-DMPC的混合物可能被证明是有用的模型膜介质中的固态NMR研究的生物膜。
Mixtures of long-chain and short-chain phosphatidylcholine (PC) were characterized by multinuclear (C-13, P-31, H-2) solid-state nuclear magnetic resonance. This work complements and extends previous characterization of such mixtures by focusing on concentrated mixtures at temperatures above the gel to liquid crystalline phase transition temperature (T(m)) of the long-chain PC component. Above T(m) it was observed that highly oriented, bilayer-like assemblies could be formed of mixtures of dimyristoylphosphatidylcholine (DMPC) and dihexanoylphosphatidylcholine (DHPC) in molar ratios ranging from approximately 1:3.5 to 1:2 (DHPC:DMPC) over a considerable range of lipid concentrations (at least 3-40% w/v total lipid, for a 1:2.5 sample). Orientation was observed to occur only in an L(alpha)-like phase. The NMR data can be accounted for by a general model of the DHPC-DMPC aggregates in which DHPC can be found in two distinct populations (one highly ordered, one not). The averaged conformations of the glycerol backbone/headgroup regions of the long- and short-chain PC composing the assemblies were judged by solid-state C-13 NMR to be similar to each other. The information gleaned about these mixtures and the quality of the oriented NMR spectra obtained suggest that DHPC-DMPC mixtures may prove to be useful as model membrane media in solid-state NMR studies of biomembranes.