Cyclic Cell-Penetrating Peptides

描述（由申请方提供）：任何预期用于细胞内靶点的治疗剂都需要能够穿过细胞膜并进入细胞内部。蛋白质、肽和小干扰RNA（siRNA）代表一些新兴/扩展类别的治疗剂。然而，这些生物分子本身通常是膜不可渗透的，必须被递送到适当的细胞内位置。细胞穿透肽（CPP）是具有穿透真核细胞质膜而不引起显著膜损伤的能力的短肽（通常<30个氨基酸）。已经发现了许多CPP，并且一些CPP已经用于将各种各样的货物递送到细胞中。先前CPP的主要限制在于，由于低效的内体逃逸，它们具有较差的总体递送效率。一个新的环状CPP家族，例如，cyclo（F？RRRRQ）在哪里？是2-萘基丙氨酸），最近在该实验室中被发现，并被发现有效地从内体逃逸。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作为生物活性分子细胞内递送的通用转运体。具体目标1是合成和筛选集中的环肽文库，以鉴定额外的和潜在的更具活性的环状CPP。具体目标2是测试可以由环状CPP递送的限制，并确定CPP内体释放的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CPP来设计针对细胞内蛋白质如癌蛋白Ras的细胞渗透性抑制剂。

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.