Center for Molecular Study of Condensed Soft Matter (muCoSM), and Division of Physics, BCPS Department, Illinois Institute of Technology, Chicago, Illinois 60616, USA.
Phys Rev Lett. 2010 Mar 12;104(10):108101. doi: 10.1103/PhysRevLett.104.108101. Epub 2010 Mar 8.
We report a structural study of cholesterol-DPPC (1,2-dipalmitoyl-sn-glycero-3-phophocholine) monolayers using x-ray reflectivity and grazing incidence x-ray diffraction. Reflectivity reveals that the vertical position of cholesterol relative to phospholipids strongly depends on its mole fraction (chi(CHOL)). Moreover, we find that at a broad range of chi(CHOL) cholesterol and DPPC form alloylike mixed domains of short-range order and the same stoichiometry as that of the film. Based on the data presented, we propose a new model of cholesterol-phospholipid organization in mixed monolayers.
我们使用 X 射线反射率和掠入射 X 射线衍射研究了胆固醇-DPPC（1,2-二棕榈酰-sn-甘油-3-磷酸胆碱）单层的结构。反射率表明，胆固醇相对于磷脂的垂直位置强烈依赖于其摩尔分数（chi(CHOL)）。此外，我们发现，在宽范围的 chi(CHOL)范围内，胆固醇和 DPPC 形成具有短程有序和与膜相同化学计量比的类似合金的混合域。基于呈现的数据，我们提出了一种混合单层中胆固醇-磷脂组织的新模型。
