Strenk L M, Westerman P W, Vaz N A, Doane J W
Biophys J. 1985 Sep;48(3):355-9. doi: 10.1016/S0006-3495(85)83791-7.
Intense motional averaging effects on the 2H nuclear magnetic resonance (NMR) spectrum of 2H2O that occur in aqueous dispersions of dimyristoyl-sn-glycero-3-phosphocholine (Myr2-PtdCho) are explained by a spatial modulation in the orientational order of the water induced by ripplelike structures. The ratio of the amplitude to the periodic length of the ripples, A/lambda, at a molar ratio of water/Myr2-PtdCho of 9.5:1, is measured by 2H NMR and found to be consistent with x-ray measurements of this ratio in the P beta phase of dipalmitoyl-sn-glycero-3-phosphocholine (Pam2-PtdCho) bilayers. The sensitivity of 2H NMR allows us to report the presence of two distinct ripple phases mediated with a discontinuous change in the value of A/lambda. This result suggests that the two ripple structures observed for several phospholipid systems in excess water by freeze-fracture electron microscopy may be associated with two different phases instead of the same phase as previously assumed.
在二肉豆蔻酰 - sn - 甘油 - 3 - 磷酸胆碱（Myr2 - PtdCho）的水分散体中，对2H2O的2H核磁共振（NMR）谱产生强烈运动平均效应，这是由波纹状结构引起的水取向有序的空间调制所解释的。在水/Myr2 - PtdCho摩尔比为9.5:1时，通过2H NMR测量波纹的振幅与周期长度之比A/λ，发现其与二棕榈酰 - sn - 甘油 - 3 - 磷酸胆碱（Pam2 - PtdCho）双层膜的Pβ相中的该比例的X射线测量结果一致。2H NMR的灵敏度使我们能够报告存在由A/λ值的不连续变化介导的两个不同的波纹相。该结果表明，通过冷冻断裂电子显微镜在过量水中观察到的几种磷脂系统的两种波纹结构可能与两个不同的相相关，而不是如先前假设的同一相。
