Water diffusion in the lamellar phase of egg phosphatidylcholine (egg PC)-water was studied by 1H NMR using the pulsed field gradient-spin echo method. The curvature of diffusion plots obtained with egg PC-water mixtures indicates that water diffusion is highly anisotropic with respect to lipid lamellae. This was confirmed by measurements made on macroscopically aligned egg PC-water as a function of orientation that categorically establish DII/DI >> .1, where the respective subscripts refer to parallel and perpendicular to the lipid bilayer. A smooth, monotonic dependence on water concentration was observed for water diffusion in aligned egg PC-water, varying at 25 degrees C from DII = 1.2 x 10(-10) m2 s 1 at n = 4.9 mol water/lipid to DII = 4.0 x 10(-10) m2 s-1 at n = 18.6 mol water/lipid. The diffusion is approximately a factor of 10 slower than in pure water because of water binding and restriction to translational motion within the aqueous layer. No evidence for a sudden drop in water diffusion coefficient at a specific water content, as previously reported with egg PC-water mixtures (Lange and Gary Bobo. 1974. J. Gen. Physiol 63:690-706), was detected. A morphological reorganization of lamellar domains, which in random orientational distribution comprise lipid-water mixtures, is the likely explanation. The study of aligned lipid-water systems is manifestly preferable.
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机译：使用脉冲场梯度自旋回波法通过1 H NMR研究了卵磷脂酰胆碱（egg PC）-水在层状相中的水扩散。用蛋PC-水混合物获得的扩散图的曲率表明，水的扩散相对于脂质薄片是高度各向异性的。这是通过对宏观排列的鸡蛋PC水进行的测量确定的，该测量是定向确定DII / DI >> .1的函数，其中各个下标均指平行和垂直于脂质双层。在对齐的鸡蛋PC水中观察到水扩散的平滑单调依赖于水浓度，在25摄氏度下，DII = 1.2 x 10（-10）m2 s 1在n = 4.9 mol水/脂质时变化为DII = 4.0 x 10（-10）m2 s-1在n = 18.6摩尔水/脂质时。由于水的结合和对水层内平移运动的限制，扩散比纯水中的扩散大约慢十倍。没有检测到在特定水含量下水扩散系数突然下降的证据，如先前报道的鸡蛋PC-水混合物（Lange和Gary Bobo。1974. J. Gen. Physiol 63：690-706）。层状结构域的形态重组可能是由随机分布的脂质-水混合物组成的。对齐脂质-水系统的研究显然是优选的。
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