Helsinki Biophysics and Biomembrane Group, Department of Biomedical Engineering and Computational Sciences, Aalto University, Espoo, Finland; Department of Medical Biochemistry, College of Medicine, Shaqra University, Shaqra, 11961, Saudi Arabia.
Institute of Biomedicine, University of Eastern Finland, 70211 Kuopio, Finland.
Int J Pharm. 2021 May 15;601:120556. doi: 10.1016/j.ijpharm.2021.120556. Epub 2021 Mar 30.
An endosomal trap is a major barrier in gene therapy. We have designed an endosomolytic peptide based on the leucine zipper sequence and characterized it both structurally and functionally. The results illustrated that leucine zipper endosomolytic peptide (LZEP) exhibited appreciable hemolysis of human red blood cells (hRBCs) at pH 5.0, but negligible hemolysis at pH 7.4. Calcein release experiment indicated that only at pH 5.0 but not at pH 7.4, LZEP was able to permeabilize hRBCs. LZEP revealed significant self-assembly as well as peptide induced α-helical structure at pH 5.0. Unlike at pH 5.0, LZEP failed to self-assemble and showed a random coil structure at pH 7.4. Transfection data depicted that lipoplexes modified with LZEP resulted in significantly higher gene expression as compared to lipoplexes without LZEP. Interestingly, the transfection efficacy of LZEP modified lipid nanoparticles reached the levels of Lipofectamine 2000 (LF 2000), without any cellular toxicity as observed by MTT assay. The results suggest a novel approach for designing endosomolytic peptides by employing the leucine zipper sequence and simultaneously the designed peptides could be utilized for enhancing gene delivery into mammalian cells.
内体陷阱是基因治疗的主要障碍。我们设计了一种基于亮氨酸拉链序列的内体溶酶肽，并对其结构和功能进行了表征。结果表明，亮氨酸拉链内体溶酶肽（LZEP）在 pH5.0 时对人红细胞（hRBC）有明显的溶血作用，但在 pH7.4 时几乎没有溶血。钙黄绿素释放实验表明，只有在 pH5.0 时，LZEP 才能通透 hRBC，而在 pH7.4 时则不能。LZEP 在 pH5.0 时表现出显著的自组装以及肽诱导的α-螺旋结构，而在 pH7.4 时则不能自组装，呈现无规卷曲结构。转染数据表明，用 LZEP 修饰的脂质体比没有 LZEP 修饰的脂质体导致更高的基因表达。有趣的是，LZEP 修饰的脂质纳米粒的转染效率达到了 Lipofectamine 2000（LF2000）的水平，而通过 MTT 测定没有观察到任何细胞毒性。结果表明，通过使用亮氨酸拉链序列设计内体溶酶肽是一种新的方法，同时设计的肽可以用于增强哺乳动物细胞的基因传递。
