Westerman P W, Pope J M, Phonphok N, Doane J W, Dubro D W
Department of Biochemistry, Northeastern Ohio Universities College of Medicine, Rootstown 44272.
Biochim Biophys Acta. 1988 Mar 22;939(1):64-78. doi: 10.1016/0005-2736(88)90048-x.
The interaction of eight n-alkanols with bilayers of dimyristoylphosphatidylcholine (DMPC) has been studied by deuterium nuclear magnetic resonance (2H-NMR). At comparable temperatures and concentrations of solute in the bilayer, order parameters measured at the 1-methylene segment of the n-alkanols show a maximum for n-dodecanol. For both n-dodecanol and n-tetradecanol, orientational ordering shows a maximum at the C-4 to C-7 methylene segments, with labels at both ends of the n-alkanol exhibiting reduced order. These observations are consistent with earlier findings for n-octanol and n-decanol. Unlike the longer chain n-alkanols, ordering in n-butanol decreases from the hydroxyl group end to the methyl group end of the molecule. Orientational ordering at nine inequivalent sites in DMPC, has also been measured as a function of temperature, for bilayers containing n-butanol, n-octanol, n-dodecanol and n-tetradecanol. At the 3R,S sites on the glycerol backbone, for comparable temperatures and solute concentrations, n-butanol produces a larger disordering than the other n-alkanols. This result probably reflects the greater fraction of time spent by the hydroxyl group of n-butanol in the vicinity of the lipid polar head group compared with the hydroxyl group in longer chain n-alkanols. It was found that n-octanol orders the acyl chains of DMPC, unlike n-butanol which disorders them, and the longer chain n-alkanols which have little effect. Within experimental error, the effect of n-dodecanol on order at all sites in DMPC is the same as n-tetradecanol. The influence of n-alkanols on DMPC ordering at twelve sites has been compared with that of cholesterol which is shown to interact with DMPC bilayers in a distinctly different manner from the n-alkanols.
利用氘核磁共振（2H-NMR）研究了八种正构烷醇与二肉豆蔻酰磷脂酰胆碱（DMPC）双层膜的相互作用。在双层膜中溶质具有可比温度和浓度的情况下，在正构烷醇的1-亚甲基段测得的序参数在正十二烷醇时达到最大值。对于正十二烷醇和正十四烷醇，取向有序性在C-4至C-7亚甲基段达到最大值，正构烷醇两端的标记显示有序性降低。这些观察结果与早期关于正辛醇和正癸醇的发现一致。与较长链的正构烷醇不同，正丁醇中的有序性从分子的羟基端到甲基端逐渐降低。还测量了含有正丁醇、正辛醇、正十二烷醇和正十四烷醇的双层膜中，DMPC九个不等价位点的取向有序性随温度的变化。在甘油主链的3R,S位点，在可比温度和溶质浓度下，正丁醇比其他正构烷醇产生更大的无序性。这一结果可能反映了与较长链正构烷醇中的羟基相比，正丁醇的羟基在脂质极性头部基团附近停留的时间比例更大。研究发现，正辛醇使DMPC的酰基链有序排列，这与使酰基链无序排列的正丁醇以及几乎没有影响的较长链正构烷醇不同。在实验误差范围内，正十二烷醇对DMPC所有位点有序性的影响与正十四烷醇相同。已将正构烷醇对DMPC十二个位点有序性的影响与胆固醇的影响进行了比较，结果表明胆固醇与DMPC双层膜的相互作用方式与正构烷醇明显不同。
