Multinuclear and magic-angle spinning NMR investigations of molecular organization in phospholipid-triglyceride aqueous dispersions.
Multinuclear and magic-angle spinning NMR investigations of molecular organization in phospholipid-triglyceride aqueous dispersions.
复制标题
磷脂-甘油三酯水分散体中分子组织的多核和魔角旋转核磁共振研究。
DOI：
10.1021/bi00089a008
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Stark,RE
中科院分区：
文献类型：
--
作者：
Li,KL;Tihal,CA;Guo,M;Stark,RE
摘要：用~（31）P、~（13）C和核磁共振（NMR）研究了卵磷脂-三油酸甘油酯（PC-）水溶液形成的多层膜的超分子结构。对于这些乳液，它模仿底物在早期水解阶段的脂肪消化，与魔角旋转（MAS）获得的NMR光谱表现出分辨率可比的超声囊泡和集成的峰强度与它们的化学组成一致。这两个31 P线形和MAS边带图案从磷酸胆碱组表明，与三油酸甘油酯混合产生的PC双层仍然主要是液晶在其组织，然而，异常的光谱特征在MAS光谱可能是由于额外的阶段，其中的头基采用不同的取向相对于双层正常的，和紧密的包装增强磷-磷相互作用。13 C和线宽作为PC摩尔分数，纺丝速度和去耦强度的函数监测表明，胆碱头基和甘油骨干优先锚定在磷脂甘油三酯组件，而所有的酰基链变得非常流畅。从MASNMR谱中的自旋边带强度判断，混合分散体的平均链有序度也降低。质子自旋扩散效应的情况下，在PC-多层膜证明通过检查其spinningsidebands和弛豫时间，使之有可能使用MAS辅助的二维NMR分配重叠的共振，并确定近端的两个成分之间的相互作用。这些NMR策略在胃脂肪消化的机理研究的有用性也discussed.Mixtures的甘油三酯和磷脂引起了相当大的关注，在过去的十年中，因为它们的意义，在动物和植物中的两种成分的水解。这仍然是一个悬而未决的问题是否小的表面人口的甘油三酯是典型的建议
Revised Manuscript Received July 1, 1993· abstract: The supramolecular organization of multi-bilayers formed by aqueous egg phosphatidylcholine-triolein (PC-) mixtures has been investigated using 31P, 13C, and nuclear magnetic resonance (NMR). For these emulsions, which mimic substrates in the early hydrolytic stages of fat digestion, the NMR spectra obtained with magic-angle spinning (MAS) exhibit resolution comparableto that of sonicated vesicles and integrated peak intensities consistent with their chemical composition. Both 31P line shapes and MAS sideband patterns from the phosphocholine group indicate that mixing with triolein produces a PC bilayer which remains predominantly liquid crystalline in its organization; nevertheless, anomalous spectral features in MAS spectra may be attributed to additional phases in which the headgroups adopt a different orientation with respect to the bilayer normal, and tight packing enhances phosphorus-phosphorus interactions. 13C and line widths monitored as a function of PC mole fraction, spinning speed, and decoupling strength show that the choline headgroups and glycerol backbones are anchored preferentially in the phospholipidtriglyceride assemblies, whereas all acyl chains become very fluid. The average degree of chain order also decreases for the mixed dispersions, as judged from spinning-sideband intensities in MASNMR spectra. The absence of proton spin-diffusion effects in the PC-multilayers is demonstrated by examination of their spinningsidebands and relaxation times, making it possible to use MAS-assisted two-dimensional NMR to assign overlapped resonances and to identify proximal interactions between the two constituents. The usefulness of these NMR strategies in mechanistic studies of gastric fat digestion is also discussed.Mixtures of triglycerides and phospholipids have attracted considerable attention during the last decade because of their significance in the hydrolysis of both constituents in animals and plants. It is still an open question whether the small surface population of triglyceride that is typical of proposed