Evaluating spin diffusion in MAS-NOESY spectra of phospholipid multibilayers

被引:19
作者
Chen, ZJ
Stark, RE
机构
[1] CUNY COLL STATEN ISL, DEPT CHEM, STATEN ISL, NY 10314 USA
[2] CUNY GRAD SCH & UNIV CTR, STATEN ISL, NY 10314 USA
关键词
bilayer; biological membrane; magic-angle spinning; nuclear Overhauser effect; phospholipid; spin diffusion;
D O I
10.1016/S0926-2040(96)01237-4
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
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.
引用
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页码:239 / 246
页数:8
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