Evaluating spin diffusion in MAS-NOESY spectra of phospholipid multibilayers
Evaluating spin diffusion in MAS-NOESY spectra of phospholipid multibilayers
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DOI：
10.1016/s0926-2040(96)01237-4
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发表时间：
1996-12-01
影响因子：
3.2
通讯作者：
Stark, RE
中科院分区：
文献类型：
--
作者：
Chen, ZJ;Stark, RE
生物半固体，如水溶性磷脂分散体，可用于结合幻角旋转（MAS）产生高分辨率H-1核磁共振光谱和二维核Overhauser光谱（NOESY）来估计质子-质子距离的实验。使用几种选择性氘化二酰基磷脂酰胆碱，系统地研究了脂质头基甲基和酰基链之间异常NOESY交叉对话的起源。尽管这些多层体系中的自旋弛豫和线缩窄行为反对有效的自旋扩散，但使这些H-1核靠近的交叉指状或链弯曲结构模型与该磷脂体系的mas - noesi结果无关。在传统的脂质双层结构中，两种甲基质子之间的自旋通信机制被提出：通过空间相互作用将相邻分子上的头基和主质子连接起来，然后沿酰基链发生自旋扩散。
Biological semisolids such as aqueous phospholipid dispersions are amenable to experiments that combine magic-angle spinning (MAS) to yield high-resolution H-1 NMR spectra and two-dimensional nuclear Overhauser spectroscopy (NOESY) to estimate proton-proton distances, Using several selectively deuterated dimyristoylphosphatidylcholines, a systematic investigation has been made into the origin of an anomalous NOESY crosspeak between methyl groups of the lipid headgroup and the acyl chains, Although the spin-relaxation and line-narrowing behavior in these multilamellar systems argue against efficient spin diffusion, interdigitated or chain-bendback structural models that bring these H-1 nuclei into close proximity are not implicated by the MAS-NOESY results for this phospholipid system. A mechanism has been proposed for spin communication between the two types of methyl protons within a conventional lipid bilayer structure: through-space interactions link the headgroup and backbone protons on adjacent molecules, and then spin diffusion occurs along the acyl chains.