Department of Chemical Engineering, and ‡Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada.
Biochemistry. 2013 May 21;52(20):3428-35. doi: 10.1021/bi4001326. Epub 2013 May 7.
The development of safe and efficient nonviral gene delivery carriers has received a great deal of attention in the past decade. A class of amphipathic peptides has shown to be able to cross cell membranes and deliver cargo to the intracellular environment. Here, we introduce an 18-mer amphipathic peptide, C6M1, as a modified version of peptide C6 for short interfering RNA (siRNA) delivery. The importance of tryptophan residues and the effect of peptide sequence modification on its solubility, secondary structure, cytotoxicity, and uptake efficiency were investigated. The solubility of C6M1 in aqueous solutions was greatly enhanced compared to that of C6, confirmed by surface tension and anilinonaphthalene-8-sulfonic acid fluorescence measurements. C6M1 had a random/helical structure in water with the ability to attain a helical conformation in the presence of anionic components or membrane-mimicking environments. The modification significantly reduced the cytotoxicity of the peptide, making it a safer carrier for siRNA delivery. C6M1 was also found ∼90% more efficient than C6 in delivering Cy3-labeled siRNA in Chinese hamster ovary cells.
在过去的十年中，安全有效的非病毒基因传递载体的开发受到了极大的关注。一类两亲性肽已被证明能够穿过细胞膜并将货物递送到细胞内环境中。在这里，我们介绍了一种 18 个氨基酸的两亲性肽 C6M1，它是短干扰 RNA（siRNA）传递的肽 C6 的改良版本。我们研究了色氨酸残基的重要性以及肽序列修饰对其溶解度、二级结构、细胞毒性和摄取效率的影响。与 C6 相比，C6M1 在水溶液中的溶解度大大提高，这通过表面张力和蒽酮萘-8-磺酸荧光测量得到了证实。C6M1 在水中具有无规/螺旋结构，并且在存在阴离子成分或模拟膜环境时能够获得螺旋构象。这种修饰显著降低了肽的细胞毒性，使其成为更安全的 siRNA 传递载体。在中华仓鼠卵巢细胞中，C6M1 比 C6 更有效地传递 Cy3 标记的 siRNA，效率提高了约 90%。
