通过固态2HNMR光谱学研究的米林和胆固醇的状混合物
Tim Bartels1, Ravi S Lankalapalli, Robert Bittman
1Laboratory of Neurodegenerative Disease Research, Ludwig-Maximilian-University, 80336 Munich, Germany.
Journal of the American Chemical Society
|October 9, 2008
概括
胆固醇会影响脂质膜结构,在中度度下,在基米林混合物中引起相分离. 这种类似的域形成对细胞膜至关重要,但在高胆固醇水平下消失.
科学领域:
- 生物物理学的生物物理.
- 膜生物物理学 膜生物物理学
- 脂质双层动力学 脂质双层动力学
背景情况:
- 斯芬哥米林是哺乳动物神经系统中的关键脂质,形成膜微域.
- 脊髓菌素的变化与衰老和神经退行性疾病有关.
- 了解脂质 - 胆固醇相互作用对于细胞膜功能至关重要.
研究的目的:
- 为了研究不同胆固醇度对脂质混合物的影响.
- 为了分析N-palmitoylsphingomyelin (PSM) 和POPC混合物的相分离.
- 为了描述由此产生的液体有序和液晶晶域.
主要方法:
- 使用了核磁共振 ((2) H NMR) 光谱法.
- 实验涉及宏观对齐和无定向的多叶膜分散.
- 分析包括结构参数的平均扭矩潜力建模.
主要成果:
- 发现了两个并存的液晶域的证据.
- 一个域表现出液体顺序相特征.
- 阶段分离发生在三元混合物中,直到胆固醇分子分数为0.33,然后消失.
结论:
- 胆固醇在中间度时会诱导浮游艇类领域的相分离.
- 首选的胆固醇 - 斯芬戈米林相互作用发生在较低的分子分数中.
- 疏水性匹配解释了域的形成,但不是在和胆固醇水平.
相关概念视频
01:13¹H NMR: Complex Splitting
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
01:35Asymmetric Lipid Bilayer
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...