Wratten M L, van Ginkel G, van't Veld A A, Bekker A, van Faassen E E, Sevanian A
Department of Pathology, University of Southern California, Los Angeles 90033.
Biochemistry. 1992 Nov 10;31(44):10901-7. doi: 10.1021/bi00159a034.
Phospholipid hydroperoxides and phospholipid alcohols are two of the major forms of oxidatively modified phospholipids produced during oxidant stress and lipid peroxidation. The process of lipid peroxidation is known to affect the physiological function of membranes. We, therefore, investigated the effects of lipid peroxidation products on the molecular interactions in membranes. Our study was specifically focused on the effects of lipid peroxidation products on static membrane structure (molecular orientational order) and on the reorientational dynamics of the probe molecules in lipid bilayers. The study was done by performing angle-resolved fluorescence depolarization measurements (AFD) on the fluorescent probe diphenylhexatriene (DPH) and by performing angle-resolved electron spin resonance (A-ESR) measurements on cholestane (CSL) nitroxide spin probes embedded in macroscopically oriented planar bilayers consisting of 2-10% 1-palmitoyl-2-(9/13-hydroperoxylinoleoyl)phosphatidylcholine (PLPC-OOH) or 1-palmitoyl-2-(9/13-hydroxylinoleoyl)phosphatidylcholine (PLPC-OH) in 1-palmitoyl-2-linoleoylphosphatidylcholine (PLPC) or dilinoleoylphosphatidylcholine (DLPC). Both probe molecules have rigid cylindrical geometries and report on the overall molecular order and dynamics. However, being more polar, the nitroxide spin probe CSL is preferentially located near the surface of the membrane, while the less polar fluorescent probe DPH reports preferentially near the central hydrophobic region of the lipid bilayers. The results show that the presence of relatively small amounts of oxidatively modified phospholipids within the PLPC or DLPC membranes causes pronounced structural effects as the molecular orientational order of the probe molecules is strongly decreased. In contrast, the effect on membrane reorientational dynamics is minimal.
磷脂氢过氧化物和磷脂醇是氧化应激和脂质过氧化过程中产生的两种主要的氧化修饰磷脂形式。已知脂质过氧化过程会影响膜的生理功能。因此，我们研究了脂质过氧化产物对膜中分子相互作用的影响。我们的研究特别关注脂质过氧化产物对静态膜结构（分子取向有序性）以及脂质双层中探针分子重取向动力学的影响。该研究通过对荧光探针二苯基己三烯（DPH）进行角分辨荧光去极化测量（AFD）以及对嵌入由1 - 棕榈酰 - 2 - 亚油酰磷脂酰胆碱（PLPC）或二亚油酰磷脂酰胆碱（DLPC）中2 - 10%的1 - 棕榈酰 - 2 -（9/13 - 氢过氧亚油酰）磷脂酰胆碱（PLPC - OOH）或1 - 棕榈酰 - 2 -（9/13 - 羟基亚油酰）磷脂酰胆碱（PLPC - OH）组成的宏观取向平面双层中的胆甾烷（CSL）氮氧化物自旋探针进行角分辨电子自旋共振（A - ESR）测量来完成。两种探针分子都具有刚性圆柱形几何结构，并反映整体分子有序性和动力学。然而，由于氮氧化物自旋探针CSL极性更强，它优先位于膜表面附近，而极性较小的荧光探针DPH则优先在脂质双层的中心疏水区域附近反映情况。结果表明，PLPC或DLPC膜中相对少量的氧化修饰磷脂的存在会导致明显的结构效应，因为探针分子的分子取向有序性显著降低。相比之下，对膜重取向动力学的影响最小。
