Cyclic Cell-Penetrating Peptides

描述(由申请人提供)：能够穿过细胞膜并进入细胞内部是任何用于细胞内靶点的治疗剂的要求。蛋白质、多肽和小干扰RNA(SiRNA)代表了一些新兴的/扩展的治疗药物类别。然而，这些生物分子本身通常是不透膜的，必须被输送到适当的细胞内位置。细胞穿透肽(CPPs)是一种短肽(通常为30个氨基酸)，具有穿透真核细胞质膜的能力，而不会对细胞膜造成明显的损伤。已经发现了许多CPP，其中一些被用来将各种各样的货物输送到细胞中。以前的CPP的一个主要局限性是，由于低效的内体逃逸，它们的总体递送效率较低。一类新的环状CPP，如Cyclo(F？RRRQ)(Where？2-萘丙氨酸)，是最近在本实验室发现的，并被发现能有效地从内体逃逸。本项目的总体目标是阐明CPP摄取和内体逃逸的机制，并开发更有效的CPP作为细胞内递送生物活性分子的通用转运体。具体目标1是合成和筛选一个有针对性的环多肽文库，以鉴定额外的和可能更有活性的环状多肽。具体目的2是测试循环CPP所能传递的限度，并确定CPP的内体释放机制以及控制内体逃逸效率的因素。最后，具体目标3是利用环状CPPs来设计针对细胞内蛋白(如癌蛋白RAS)的细胞通透性抑制剂。

DESCRIPTION (provided by applicant): The ability to cross the cell membrane and gain access to the cell interior is a requirement for any therapeutic agent intended for an intracellula target. Proteins, peptides, and small interfering RNA (siRNA) represent some of the emerging/expanding classes of therapeutic agents. However, these biological molecules are generally membrane impermeable on their own and must be delivered to the proper intracellular locations. Cell-penetrating peptides (CPPs) are short peptides (usually <30 amino acids) that have the ability to penetrate the plasma membrane of eukaryotic cells without causing significant membrane damage. Many CPPs have been discovered and some have been used to deliver a wide variety of cargos into cells. A major limitation of previous CPPs is that they have poor overall delivery efficiency due to inefficient endosomal escape. A new family of cyclic CPPs, e.g., cyclo(F?RRRRQ) (where ? is 2-naphthylalanine), was recently discovered in this laboratory and found to escape from the endosome efficiently. The overall objective of this project is to elucidate the mechanisms of CPP uptake and endosomal escape and develop more potent CPPs as general transporters for intracellular delivery of biological active molecules. Specific Aim 1 is to synthesize and screen a focused cyclic peptide library to identify additional and potentially more active cyclic CPPs. Specific Aim 2 is to test the limits of what ca be delivered by the cyclic CPPs and determine the mechanism of CPP endosomal release as well as the factors that control the endosomal escape efficiency. Finally, Specific Aim 3 is to utilize the cyclic CPPs to design cell permeable inhibitors against intracellular proteins such as the oncoprotein Ras.