We investigate the effects on the distribution of lipids in the plasma membrane that are caused by the insertion of a protein, Piezo1, that significantly distorts the membrane toward the cytosol. From coarse-grained molecular dynamics simulations, we find that the major effects occur in the outer, extracellular, leaflet. The mol fraction of cholesterol increases significantly in the curved region of the membrane close to Piezo1, while those of phosphatidylcholine and of sphingomyelin decrease. In the inner leaflet, mol fractions of cholesterol and of phosphatidylethanolamine decrease slightly as the protein is approached, while that of phosphatidylserine increases slightly. The mol fraction of phosphatidylcholine decreases markedly as the protein is approached. Most of these results are understood in the context of a theoretical model that utilizes two elements: 1) a coupling between the leaflets’ actual curvatures and their compositionally dependent spontaneous curvatures and 2) the dependence of the spontaneous curvatures not only on the mol fractions of the phospholipids, but also on the effect that cholesterol has on the spontaneous curvatures of the phospholipids.

我们研究了由插入蛋白质 Piezo1 引起的质膜中脂质分布的影响，该蛋白质显着扭曲细胞质膜。从粗粒度分子动力学模拟中，我们发现主要影响发生在外部、细胞外、小叶中。在靠近 Piezo1 的膜弯曲区域，胆固醇的摩尔分数显着增加，而磷脂酰胆碱和鞘磷脂的摩尔分数则降低。在内叶中，胆固醇和磷脂酰乙醇胺的摩尔分数随着蛋白质的接近略有下降，而磷脂酰丝氨酸略有增加。随着接近蛋白质，磷脂酰胆碱的摩尔分数显着降低。这些结果中的大部分是在利用两个元素的理论模型的背景下理解的：1）传单的实际曲率与其成分相关的自发曲率之间的耦合，以及 2）自发曲率的依赖性不仅取决于摩尔分数磷脂，还有胆固醇对磷脂自发曲率的影响。