Cytosolic Targeting of Macromolecules Using a pH-Dependent Fusogenic Peptide in Combination with Cationic Liposomes
Cytosolic Targeting of Macromolecules Using a pH-Dependent Fusogenic Peptide in Combination with Cationic Liposomes
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DOI：
10.1021/bc800530v
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发表时间：
2009-05-01
影响因子：
4.7
通讯作者：
Futaki, Shiroh
中科院分区：
文献类型：
--
作者：
Kobayashi, Sachiko;Nakase, Ikuhiko;Futaki, Shiroh
pH 敏感肽和聚合物已被用作添加剂，通过促进药物和基因的内体逃逸来增强药物和基因的胞质递送。然而，人们很少关注这些肽和聚合物的细胞内命运。在这项研究中，我们探索了利用 GALA（一种 pH 敏感的融合肽）作为细胞质靶向载体的可能性。与阳离子脂质体 Lipofectamine 2000 (LF2000) 结合，通过在含血清介质中递送抗生物素蛋白 (68 kDa) 和链霉抗生物素蛋白包被的量子点 (15-20 nm)，例证了这种方法用于胞质靶向蛋白质和纳米粒子的可行性。阳离子脂质体的使用对于增强 GALA 缀合物的细胞表面粘附和最终内体摄取至关重要。圆二色性研究表明，GALA 可以在 pH 值降低的情况下从阳离子脂质体中释放出来，形成螺旋结构，这可能最终导致内体膜的破坏，从而实现 GALA 缀合物有效渗漏到细胞质中。
pH-Sensitive peptides and polymers have been employed as additives to enhance the cytosolic delivery of drugs and genes by facilitating their endosomal escape. However, little attention has been paid to the intracellular fate of these peptides and polymers. In this study, we explored the possibility of utilizing GALA, a pH-sensitive fusogenic peptide, as a cytosol-targeting vehicle. In combination with cationic liposomes, Lipofectamine 2000 (LF2000), the feasibility of this approach for the cytosolic targeting of proteins and nanoparticles was exemplified through the delivery of avidin (68 kDa) and streptavidin-coated quantum dots (15-20 nm) in serum-containing medium. The use of cationic liposomes is critical to enhance the cell-surface adhesion of the GALA conjugates and eventual endosomal uptake. Circular dichroism studies suggest that the GALA can be liberated from cationic liposomes at a reducing pH to form a helical structure and this may eventually lead to disruption of the endosomal membrane to achieve an efficient leakage of the GALA conjugates into the cytosol.