Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA.
J Drug Target. 2011 Sep;19(8):675-80. doi: 10.3109/1061186X.2010.531729. Epub 2010 Dec 9.
Properties of different arginine-rich peptides, including net charge and charge distribution, were evaluated for their influence on surface binding, internalization, and intracellular localization. The peptides were radiolabeled and subsequently tested for surface binding and internalization in CHO-K1 cells. Subcellular fractionation assays were performed to separate the amount of peptides associated within vesicles from those inside the cytosol. Net neutral charged peptides, YGR(6)E(6) and YG(RE)(6), showed large decreases in both surface binding and cell uptake compared to their net positive charged counterparts, YGR(6)G(6) and YG(RG)(6). The peptides with clustered arginine residues, YGR(6)G(6) and YGR(6)E(6), exhibited significantly higher binding and uptake than those with alternating arginine and glycine/glutamate residues, YG(RG)(6) and YG(RE)(6). The intracellular distribution analysis for all of the peptides tested showed that, regardless of the net uptake, the arginine-rich peptides were preferentially localized in the cytosolic compartment of the cells. Both net positive charge and a clustered arginine sequence enhance the surface binding and internalization of peptides; however, the cytosolic versus vesicular intracellular distribution does not change. The results presented in this report provide important information regarding the specificity of binding and internalization of arginine-rich peptides, which is necessary for the future design of targeted drug delivery systems.
不同精氨酸丰富肽的性质，包括净电荷和电荷分布，因其对表面结合、内化和细胞内定位的影响而被评估。这些肽被放射性标记，随后在 CHO-K1 细胞中测试其表面结合和内化。进行亚细胞分级分离测定以将与囊泡内相关的肽的量与细胞质内的肽的量分离。与带净正电荷的对应物 YGR(6)G(6)和 YG(RG)(6)相比，净中性带电荷的肽 YGR(6)E(6)和 YG(RE)(6)在表面结合和细胞摄取方面均大大减少。带聚集精氨酸残基的肽 YGR(6)G(6)和 YGR(6)E(6)表现出比具有交替的精氨酸和甘氨酸/谷氨酸残基的肽 YG(RG)(6)和 YG(RE)(6)更高的结合和摄取。对所有测试的肽的细胞内分布分析表明，无论净摄取如何，富含精氨酸的肽都优先定位于细胞的细胞质区室中。正净电荷和聚集的精氨酸序列均增强了肽的表面结合和内化；然而，细胞内囊泡内与细胞质内的分布并没有改变。本报告中提出的结果提供了关于富含精氨酸的肽的结合和内化特异性的重要信息，这对于靶向药物递送系统的未来设计是必要的。
