FLUORESCENCE STUDIES OF BIOPHYSICAL PROPERTIES OF POLYUNSATURATED PHOSPHOLIPIDS

多不饱和磷脂生物物理性质的荧光研究

• 批准号: 3789513
• 负责人: N SALEM
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3789513
• 关键词: alcoholic beverage consumption; arachidonate; biophysics; drug withdrawal; ethanol; fluorescent dye /probe; laboratory rat; lipid bilayer membrane; membrane activity; membrane lipids; microsomes; omega 3 fatty acid; phospholipids; saturated /unsaturated bonds; unsaturated fatty acids

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.

酒精引起的多不饱和脂质消耗会改变身体 以及生物膜的功能特性。 长期酗酒 已知暴露会导致对乙醇诱导的膜产生抗性 混乱。 我们实验室的荧光研究证实了这一点 大鼠肝微粒体的反应在停药后 2 至 3 天恢复。 使用 DPH 测量大容量膜“流动性”，未发现差异 对照组和肝微粒体之间的基底膜顺序 撤退组。 然而，局部膜探针 TMA-DPH 检测到 戒断后 24 小时内暴露于酒精的动物，戒断 具有较高膜序的组。 荧光探针定位于 这些双层的特定区域表明酒精引起的变化 脂质成分影响非常不同的脂质的膜组织 域。 此外，我们的实验室表明，酒精会消耗 长链多不饱和脂肪酸，例如 20:4n6 和 22:6n3 膜。 我们假设有一个专业化 22:6-磷脂在生物体内的定位和功能 膜。 为了检验这个假设，2:6n3 的物理环境和 已使用荧光研究了其他多不饱和磷脂 小单层囊泡的各向异性。 我们发现，在下 限定条件下，含有 22:6n3 物种的双层变得更高 比含有较少双键物质的双层更堆积。 然而， 相同样本的旋转相关时间表明局部 沿着脂肪酰基链的环境变得越来越无序 随着不饱和度的增加。