Jagiellonian University, Faculty of Chemistry, Kraków, Poland.
Colloids Surf B Biointerfaces. 2012 May 1;93:174-9. doi: 10.1016/j.colsurfb.2011.12.035. Epub 2012 Jan 9.
In this work the properties of two ternary sphingomyelin/phosphatidylcholine/cholesterol monolayers imitating erythrocyte membrane were studied at various content of sterol. Phosphatidylcholines chosen for experiments differ in the length of sn-1 saturated chain in the molecule (1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine-SOPC vs. 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine - POPC). Langmuir monolayer experiments combined with Brewster Angle Microscopy prove that for both investigated systems the most favorable effect of cholesterol appears at 30% of sterol in the film. However, the interactions between molecules at 50% of sterol are only slightly weaker as compared to those for 1:1:1 films. It was also found that only at higher sterol concentration appear differences in the ordering effect of cholesterol on the systems containing PC molecules of various length of sn-1 saturated chain. Although the differences in the properties of POPC versus SOPC-containing monolayers were found, similarities in the morphology of the respective systems and stoichiometry of thermodynamically the most favorable mixture allow one to conclude that both SM/POPC/Chol as well as SM/SOPC/Chol monolayer can be used to mimic raft systems.
本工作研究了两种模拟红细胞膜的三元神经鞘磷脂/磷脂酰胆碱/胆固醇单层在不同甾醇含量下的性质。选择用于实验的磷脂酰胆碱在分子中 sn-1 饱和链的长度上有所不同（1-硬脂酰-2-油酰-sn-甘油-3-磷酸胆碱-SOPC 与 1-棕榈酰-2-油酰-sn-甘油-3-磷酸胆碱-POPC）。Langmuir 单层实验结合布鲁斯特角显微镜证明，对于这两种被研究的体系，胆固醇的最有利作用出现在薄膜中胆固醇含量为 30%时。然而，与 1:1:1 薄膜相比，胆固醇在 50%甾醇条件下与分子的相互作用仅略弱。还发现，只有在较高的甾醇浓度下，胆固醇对含有不同 sn-1 饱和链长的 PC 分子的体系的有序化作用才会出现差异。尽管发现了含有 POPC 和 SOPC 的单层之间的性质差异，但在各自体系的形态和热力学上最有利的混合物的化学计量上的相似性使得人们可以得出结论，即 SM/POPC/Chol 和 SM/SOPC/Chol 单层都可以用来模拟筏系统。
