论文标题
胆固醇在磷脂双层中的作用的机械观点
A mechanistic perspective on the effect of cholesterol in phospholipid bilayers
论文作者
论文摘要
胆固醇（CHOL）是较高细胞的质膜最重要的成分之一，也是（NANO）结构域形成的主要因素之一。在这项工作中，将CHOL与DPPC（饱和脂质）和DLIPC（不饱和脂质）作为标准磷脂（PLS）的分子动力学模拟以广泛的浓度呈现。关键思想是系统地提取与这些系统的晶格模型的制定相关的所有结构和焓特性，并以依赖酰基链阶参数的依赖表示它们。通过观察结果，可以简化详细的解释，即，对于良好的近似，相互作用效应不取决于总的CHOL浓度，而仅取决于局部的CHOL排列。所得的信息可用于激励CHOL分子的聚集，熵而非焓效应的相关性，用于理解与DPLIPC相比的CHOL对DPPC的更强影响或筏组的热力学背景。可以验证的是，在从二进制混合物到三元混合物的过渡过程中，相互作用的功能几乎不会变化，这表明概念对更复杂的混合物的适用性。
Cholesterol (CHOL) is one of the most important components of plasma membranes of higher cells and one of the main factors for the formation of (nano)domains. In this work, molecular dynamics simulations of mixtures of CHOL with DPPC (saturated lipid) and DLiPC (unsaturated lipid) as standard phospholipids (PLs) are presented in a wide range of CHOL concentrations. The key idea is to systematically extract all structural and enthalpic properties relevant to the formulation of a lattice model of these systems and express them in dependence of the acyl chain order parameters. Detailed interpretation is simplified by the observation that, to a good approximation, the interaction effects do not depend on the total CHOL concentration, but only on the local CHOL arrangement. The resulting information can be used to motivate the agglomeration of CHOL molecules, the relevance of entropic rather than enthalpic effects for understanding the stronger influence of CHOL on DPPC compared to DLiPC, or the thermodynamic background of raft formation. It is verified that the interaction functions hardly change during the transition from binary to ternary mixtures, suggesting the applicability of the concepts to more complex mixtures.
