Watson Gabrielle M, Kulkarni Ketav, Brandt Rebecca, Del Borgo Mark P, Aguilar Marie-Isabel, Wilce Jacqueline A
Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Wellington Road, Clayton, VIC 3800, Australia.
ACS Omega. 2017 Feb 28;2(2):670-677. doi: 10.1021/acsomega.6b00561. Epub 2017 Feb 23.
Delivery across the cell membrane is of critical importance for the development of therapeutics targeting intracellular proteins. The use of cell-penetrating peptides (CPPs), such as Penetratin (P16), has facilitated the delivery of otherwise cell-impermeable molecules allowing them to carry out their biological function. A truncated form of Penetratin (RRMKWKK) has been previously described as the minimal Penetratin sequence that is required for translocation across the cell membrane. Here, we performed a detailed comparison of cellular uptake by Penetratin (P16) and the truncated Penetratin peptide (P7), including their ability to deliver G7-18NATE, a cyclic peptide targeting the cytosolic cancer target Grb7-adapter protein into cells. We identified that both P16 and P7 were internalized by cells to comparable levels; however, only P16 was effective in delivering G7-18NATE to produce a biological response. Live-cell imaging of fluorescein isothiocyanate-labeled peptides suggested that while P7 may be taken up into cells, it does not gain access to the cytosolic compartment. Thus, this study has identified that the P7 peptide is a poor CPP for the delivery of G7-18NATE and may also be insufficient for the intracellular delivery of other bioactive molecules.
对于针对细胞内蛋白质的治疗药物的开发而言，跨细胞膜递送至关重要。使用细胞穿透肽（CPPs），如穿膜肽（P16），有助于递送原本无法穿透细胞的分子，使其能够发挥生物学功能。穿膜肽的截短形式（RRMKWKK）先前已被描述为跨细胞膜转运所需的最小穿膜肽序列。在此，我们对穿膜肽（P16）和截短的穿膜肽（P7）的细胞摄取进行了详细比较，包括它们将靶向胞质癌靶点Grb7衔接蛋白的环肽G7-18NATE递送至细胞内的能力。我们发现P16和P7均被细胞内化至相当水平；然而，只有P16能够有效地递送G7-18NATE以产生生物学反应。异硫氰酸荧光素标记肽的活细胞成像表明，虽然P7可能被细胞摄取，但它无法进入胞质区室。因此，本研究确定P7肽对于递送G7-18NATE而言是一种较差的细胞穿透肽，对于其他生物活性分子的细胞内递送可能也不足。
