Mandal Pritam, Noutsi Pakiza, Chaieb Sahraoui
Biological and Environmental Science and Engineering, KAUST, Thuwal, 23955, KSA.
Lawrence Berkeley National Laboratory, 1 cyclotron road, Mailstop 6R-2100, Berkeley, CA-94720, USA.
Sci Rep. 2016 Jun 1;6:26907. doi: 10.1038/srep26907.
Cholesterol is crucial to the mechanical properties of cell membranes that are important to cells' behavior. Its depletion from the cell membranes could be dramatic. Among cyclodextrins (CDs), methyl beta cyclodextrin (MβCD) is the most efficient to deplete cholesterol (Chol) from biomembranes. Here, we focus on the depletion of cholesterol from a C16 ceramide/cholesterol (C16-Cer/Chol) mixed monolayer using MβCD. While the removal of cholesterol by MβCD depends on the cholesterol concentration in most mixed lipid monolayers, it does not depend very much on the concentration of cholesterol in C16-Cer/Chol monolayers. The surface pressure decay during depletion were described by a stretched exponential that suggested that the cholesterol molecules are unable to diffuse laterally and behave like static traps for the MβCD molecules. Cholesterol depletion causes morphology changes of domains but these disrupted monolayers domains seem to reform even when cholesterol level was low.
胆固醇对于细胞膜的机械性能至关重要，而细胞膜的机械性能对细胞行为很重要。从细胞膜中去除胆固醇可能会产生显著影响。在环糊精（CDs）中，甲基-β-环糊精（MβCD）是从生物膜中去除胆固醇（Chol）最有效的。在此，我们重点研究使用MβCD从C16神经酰胺/胆固醇（C16-Cer/Chol）混合单层中去除胆固醇的情况。虽然在大多数混合脂质单层中，MβCD去除胆固醇取决于胆固醇浓度，但在C16-Cer/Chol单层中，它对胆固醇浓度的依赖性不是很强。去除过程中的表面压力衰减用拉伸指数来描述，这表明胆固醇分子无法横向扩散，并且对于MβCD分子而言表现得像静态陷阱。胆固醇的去除会导致结构域的形态变化，但即使胆固醇水平较低，这些被破坏的单层结构域似乎也会重新形成。
