FLUORESCENCE STUDIES OF BIOPHYSICAL PROPERTIES OF POLYUNSATURATED PHOSPHOLIPIDS

酒精引起的多不饱和脂肪的耗竭改变了身体 以及生物膜的功能特性。慢性酒精 已知暴露会导致对乙醇诱导的细胞膜产生抗性。 杂乱无章。我们实验室的荧光研究证实这一点 戒断后2~3天，大鼠肝微粒体反应恢复正常。 用DPH测量整体膜的“流动性”没有发现差异 对照和肝微粒体之间的基膜顺序 戒断组。然而，一种定位的膜探针TMA-DPH，检测到 一种酒精暴露动物在戒断后24小时，戒断 具有较高膜有序度的组。荧光探针定位于 这些双层膜的特定区域表明，酒精诱导的细胞内 脂类成分影响极不同脂类的膜组织 域名。此外，我们的实验室已经证明，酒精会耗尽 长链多不饱和脂肪酸，如20：4n6和22：6n3 膜。我们假设，在 22：6-磷脂在生物学中的定位和功能 膜。为了验证这一假设，2：6n3和 其他多不饱和磷脂已经用荧光进行了研究。 小单层囊泡的各向异性。我们发现，在 在规定的条件下，含有22：6n3物种的双层膜变得更高 与含有较少双键的物种的双层相比，填充的。然而， 相同样品的旋转相关时间表明，局部 沿着脂肪酰链的环境变得越来越无序 随着不饱和度的增加。

Alcohol induced depletion of polyunsaturated lipids alters the physical and functional properties of biological membranes. Chronic alcohol exposure is known to cause resistance to ethanol induced membrane disordering. Fluorescence studies in our laboratory confirm that this response recovers 2 to 3 days post-withdrawal in rat liver microsomes. Bulk membrane "fluidity" measurements with DPH detect no difference in basal membrane order between controls and liver microsomes from the withdrawal group. However, a localized membrane probe, TMA-DPH, detected a alcohol-exposed animals at 24 hours post-withdrawal, the withdrawal group having a higher membrane order. Fluorescent probes localized in specific areas of these bilayers suggest that alcohol induced changes in lipid composition affect membrane organization in very distinct lipid domains. Furthermore, our laboratory has shown that alcohol depletes the long chain polyunsaturated fatty acids such as 20:4n6 and 22:6n3 from membranes. We hypothesize that there is a specialization in the localization and function of the 22:6-phospholipids in biological membranes. To test this hypothesis, the physical environment of 2:6n3 and other polyunsaturated phospholipids have been studied using fluorescence anisotropy in small unilamellar vesicles. We have found that under defined conditions, bilayers containing 22:6n3 species become more highly packed than bilayers containing species with fewer double bonds. However, rotational correlation times of the same samples indicate that the local environment along the fatty acyl chains becomes increasingly disordered with increasing unsaturation.