Division of Organic Chemistry, National Institute of Health Sciences, Kawasaki-shi 210-9501, Japan.
Division of Pharmaceutical Organic Chemistry, Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda-shi 756-0884, Japan.
Int J Mol Sci. 2023 Jul 21;24(14):11768. doi: 10.3390/ijms241411768.
Cell-penetrating peptides (CPPs) are widely used for the intracellular delivery of a variety of cargo molecules, including small molecules, peptides, nucleic acids, and proteins. Many cationic and amphiphilic CPPs have been developed; however, there have been few reports regarding hydrophobic CPPs. Herein, we have developed stapled hydrophobic CPPs based on the hydrophobic CPP, TP10, by introducing an aliphatic carbon side chain on the hydrophobic face of TP10. This side chain maintained the hydrophobicity of TP10 and enhanced the helicity and cell penetrating efficiency. We evaluated the preferred secondary structures, and the ability to deliver 5(6)-carboxyfluorescein (CF) as a model small molecule and plasmid DNA (pDNA) as a model nucleotide. The stapled peptide with CF, in which the stapling structure was introduced at Gly residues, formed a stable α-helical structure and the highest cell-membrane permeability via an endocytosis process. Meanwhile, peptide demonstrated remarkable stability when forming a complex with pDNA, making it the optimal choice for the efficient intracellular delivery of pDNA. The results showed that stapled hydrophobic CPPs were able to deliver small molecules and pDNA into cells, and that different stapling positions in hydrophobic CPPs can control the efficiency of the cargo delivery.
细胞穿透肽（CPPs）广泛用于将各种货物分子（包括小分子、肽、核酸和蛋白质）递送到细胞内。已经开发了许多阳离子和两亲性 CPPs；然而，关于疏水性 CPPs 的报道却很少。在这里，我们通过在 TP10 的疏水面上引入脂肪碳侧链，基于疏水性 CPP TP10 开发了订书肽疏水性 CPP。该侧链保持了 TP10 的疏水性，并增强了螺旋性和细胞穿透效率。我们评估了首选的二级结构，以及作为模型小分子的 5(6)-羧基荧光素 (CF) 和作为模型核苷酸的质粒 DNA (pDNA) 的递药能力。带有 CF 的订书肽，其订书结构被引入甘氨酸残基中，形成了稳定的α-螺旋结构，并通过内吞作用具有最高的细胞膜通透性。同时，肽 与 pDNA 形成复合物时表现出显著的稳定性，使其成为有效递送入胞 pDNA 的最佳选择。结果表明，订书肽疏水性 CPP 能够将小分子和 pDNA 递送到细胞内，并且疏水性 CPP 中的不同订书位置可以控制货物递药的效率。
