Peng X, Jonas A, Jonas J
Department of Chemistry, School of Chemical Sciences, University of Illinois, Urbana 61801.
Chem Phys Lipids. 1995 Jan 12;75(1):59-69. doi: 10.1016/0009-3084(94)02403-R.
One and two dimensional 1H-NMR experiments have been performed to study the molecular order and dynamics of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) unilamellar vesicles under the influence of high pressure and the local anesthetic, tetracaine (TTC), which can also be considered as a model-charged amphiphile. The TTC molecules have an ordering effect on the headgroups but a disordering effect on the acyl chains, whereas, pressure has an ordering effect on the acyl chains. The results from 2D NOESY experiments on pure DPPC vesicles show that the intensities of NMe3/CH3, NMe3/(CH2)n, and CH3/(CH2)n cross-peaks increase with increasing pressure in the liquid-crystalline phase but decrease with pressure in the gel phase, further suggesting that the appearance of the cross-peaks between the two extremes of the DPPC molecules is due to spin-diffusion. For the DPPC/TTC vesicles, the 2D NOESY experiments confirm that charged TTC molecules are located in the headgroup region of the DPPC bilayers and, in the gel phase, also suggest the formation of an interdigitated gel phase.
已进行一维和二维¹H-NMR实验，以研究在高压和局部麻醉剂丁卡因（TTC，也可视为一种带电荷的两亲模型分子）影响下，1,2-二棕榈酰-sn-甘油-3-磷酸胆碱（DPPC）单层囊泡的分子排列和动力学。TTC分子对头部基团有有序化作用，但对酰基链有无序化作用，而压力对酰基链有有序化作用。对纯DPPC囊泡进行的二维NOESY实验结果表明，在液晶相中，NMe₃/CH₃、NMe₃/(CH₂)ₙ和CH₃/(CH₂)ₙ交叉峰的强度随压力增加而增加，但在凝胶相中随压力降低，这进一步表明DPPC分子两个极端之间交叉峰的出现是由于自旋扩散。对于DPPC/TTC囊泡，二维NOESY实验证实，带电荷的TTC分子位于DPPC双层膜的头部基团区域，并且在凝胶相中，还表明形成了一种交错的凝胶相。
