Cell-Penetrating Peptide Induces Leaky Fusion of Liposomes Containing Late Endosome-Specific Anionic Lipid
Cell-Penetrating Peptide Induces Leaky Fusion of Liposomes Containing Late Endosome-Specific Anionic Lipid
复制标题
DOI：
10.1016/j.bpj.2010.08.029
复制
发表时间：
2010-10-20
影响因子：
3.4
通讯作者：
Melikov, Kamran
中科院分区：
文献类型：
--
作者：
Yang, Sung-Tae;Zaitseva, Elena;Melikov, Kamran
阳离子细胞穿透肽是一种很有前途的大分子药物载体。尽管许多研究表明CPP通过内吞作用进入细胞，但它们穿过内体膜的机制仍然不清楚。在脂质体实验的基础上，我们提出CPP逃逸到胞质溶胶中是基于渗漏融合（即，与膜透化相关的融合）的晚期内体的双（单酰基甘油）磷酸（BMP）富集膜。在我们的实验中，原型CPP HIV-1达特肽不与模拟质膜外小叶的脂质体相互作用，但当它易位到模拟晚期内体脂质组成的脂质体中时，它确实诱导脂质混合和膜渗漏。膜渗漏和脂质混合都依赖于BMP含量，并在酸性pH下得到促进，这是晚期内体的特征。BMP与其结构异构体，磷脂酰甘油（PG）的取代，显着减少了从脂质体和脂质体之间的脂质混合的水性探针的泄漏。虽然亲和性结合到达特是相似的BMP和PG，BMP表现出更高的倾向，支持倒置的六边形相比PG。最后，膜渗漏和肽易位都被抑制的脂质混合的抑制剂，进一步证实了假设，阳离子肽跨BMP富集膜诱导泄漏之间的融合。
Cationic cell-penetrating peptides (CPPs) are a promising vehicle for the delivery of macromolecular drugs. Although many studies have indicated that CPPs enter cells by endocytosis, the mechanisms by which they cross endosomal membranes remain elusive. On the basis of experiments with liposomes, we propose that CPP escape into the cytosol is based on leaky fusion (i.e., fusion associated with the permeabilization of membranes) of the bis(monoacylglycero)phosphate (BMP)-enriched membranes of late endosomes. In our experiments, prototypic CPP HIV-1 TAT peptide did not interact with liposomes mimicking the outer leaflet of the plasma membrane, but it did induce lipid mixing and membrane leakage as it translocated into liposomes mimicking the lipid composition of late endosome. Both membrane leakage and lipid mixing depended on the BMP content and were promoted at acidic pH, which is characteristic of late endosomes. Substitution of BMP with its structural isomer, phosphatidylglycerol (PG), significantly reduced both leakage of the aqueous probe from liposomes and lipid mixing between liposomes. Although affinity of binding to TAT was similar for BMP and PG, BMP exhibited a higher tendency to support the inverted hexagonal phase than PG. Finally, membrane leakage and peptide translocation were both inhibited by inhibitors of lipid mixing, further substantiating the hypothesis that cationic peptides cross BMP-enriched membranes by inducing leaky fusion between them.