NUCLEAR RELAXATION STUDIES OF LECITHIN BILAYERS
NUCLEAR RELAXATION STUDIES OF LECITHIN BILAYERS
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DOI：
10.1038/231110a0
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发表时间：
1971-01-01
期刊：
影响因子：
64.8
通讯作者：
SEITER, CHA
中科院分区：
文献类型：
--
作者：
CHAN, SI;FEIGENSON, GW;SEITER, CHA
脂类的双层相具有宽的质子磁共振(PMR)谱，这归因于由于慢分子运动而导致不同质子之间的偶极-偶极相互作用的不完全平均1，2。然而，两个脉冲核磁共振(NMR)研究表明，内部磁场梯度是光谱展宽的来源。Kaufmanet等人的结论是，这些梯度导致了非均质性的扩大3，而Hansen和Lawson提出了通过它们的分子扩散4。这些结论是基于光谱宽度对外加磁场的明显依赖以及横向弛豫时间(T2)的突变，而在双层相界4、5处的纵向弛豫时间(T1)没有伴随的变化。Carr-Purcell实验6中T2对脉冲间距的依赖也被认为是分子通过内部磁场梯度扩散的证据。
BILAYER phases of lipids have broad proton magnetic resonance (PMR) spectra, which have been attributed to incomplete averaging of the dipole–dipole interactions between various protons as a result of slow molecular motion1,2. Two pulsed nuclear magnetic resonance (NMR) studies, however, have proposed internal magnetic field gradients as the source of spectral broadening. Kaufmanet al.concluded that these gradients led to inhomogeneity broadening3, whereas Hansen and Lawson proposed molecular diffusion through them4. These conclusions were based on the apparent dependence of the spectral width on the applied magnetic field5as well as abrupt changes in transverse relaxation time (T2) without concomitant changes in the longitudinal relaxation time (T1) at the bilayer phase boundaries4,5. The dependence ofT2on pulse spacing in a Carr–Purcell experiment6has also been taken as evidence for molecular diffusion through internal magnetic field gradients4.