CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Laboratoire des Biomolécules, Paris, France.
PLoS One. 2019 Jan 23;14(1):e0210985. doi: 10.1371/journal.pone.0210985. eCollection 2019.
Cell penetrating peptides (CPPs) are able to transport hydrophilic molecules inside cells. To reach the cytosol, the peptide associated with a cargo must cross the plasma or the endosomal membrane. Different molecular mechanisms for peptide internalisation into cells have been proposed and it is becoming clear that the cellular internalisation mechanisms are different depending on the peptide sequence and structure and the target membrane. Herein, the penetration of three peptides into large unilamellar vesicles were studied: the homeodomain derived 16-residues penetratin, nona-arginine (R9), and a small peptide containing 6 arginine and 3 tryptophan residues (RW9). The membrane models were composed of phospholipids from natural sources containing different molecular species. We observed that among the three peptides, only the amphipathic peptide RW9 was able to cross the membrane vesicles in the liquid disordered state. The changes in the distribution of the previously characterized cholesterol-pyrene probe show that cholesterol-pyrene molecules dissociate from clusters upon membrane interaction with the three peptides and that the cholesterol environment becomes more disordered in the presence of RW9. Finally, we studied the effect of the peptides on lipid ordering on giant plasma membrane vesicles. The amphipathic peptides RW9 and its longer homologue RW16 induced lipid de-packing in plasma membrane vesicles. Overall, the data suggest that a disordered membrane favours the translocation of RW9, that the membrane cholesterol is redistributed during peptide interaction, and that the peptide amphipathic character is important to increase membrane fluidity and peptide membrane translocation.
细胞穿透肽 (CPPs) 能够将亲水分子运送到细胞内部。为了到达细胞质，与货物结合的肽必须穿过质膜或内体膜。已经提出了不同的肽内化到细胞中的分子机制，并且越来越清楚的是，细胞内化机制取决于肽序列和结构以及靶膜而不同。本文研究了三种肽进入大单室囊泡的穿透情况：同源域衍生的 16 个残基穿透肽、非精氨酸 (R9) 和含有 6 个精氨酸和 3 个色氨酸残基的小肽 (RW9)。膜模型由含有不同分子种类的天然来源的磷脂组成。我们观察到，在这三种肽中，只有两亲肽 RW9 能够穿过处于无序状态的膜囊泡。先前表征的胆固醇-芘探针的分布变化表明，胆固醇-芘分子在与三种肽相互作用时从簇中解离，并且在 RW9 存在下胆固醇环境变得更加无序。最后，我们研究了肽对巨细胞膜囊泡中脂质有序性的影响。两亲肽 RW9 和其较长的同源物 RW16 诱导质膜囊泡中的脂质去组装。总的来说，数据表明无序膜有利于 RW9 的转位，肽相互作用过程中膜胆固醇重新分布，并且肽的两亲性特征对于增加膜流动性和肽膜转位很重要。
