A MULTIDISCIPLINARY APPROACH TO PEPTIDE-BASED ANTAGONISTS OF PCNA

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 细胞增殖依赖于细胞内和细胞外多价相互作用。开发新型 治疗疾病的方法需要开发效应物和抑制剂， 细胞增殖的许多过程的基础。有效的多价配体的开发 蛋白质、DNA和细胞表面需要多学科的方法，包括（a） 用于各个结合位点的优化配体;（B）能够高度精确地分离 单价配体用于在靶上的多个位点处优化相互作用， 焓和熵，而不引入通常观察到的显著熵或熵罚 （c）以多价连接多个配体和间隔元件的连接方法， 方式在这个子项目中，我们描述了一个多学科的方法来开发新的肽为基础的 增殖细胞核抗原（PCNA）的拮抗剂。PCNA是一种三聚体蛋白， 通过与包括复制DNA在内的许多蛋白质相互作用的细胞增殖调节因子 聚合酶。肿瘤抑制因子p21通过与PCNA结合并阻止其他细胞蛋白发挥作用 获取增殖细胞核抗原我们正在开发的方法，以获得高效的配体的PCNA通过一个 多学科的方法，采用以下具体目标：（1）新的PCNA的发展 通过噬菌体肽库和环肽库筛选配体;（2）PCNA检测方法的发展 DNA聚合酶活性的结合和拮抗作用;（3）二价和三价抑制剂的开发 通过开发能够最佳地将多个配体置于PCNA上的新型间隔区和接头， PCNA和防止PCNA与其他细胞靶点的相互作用。这种方法，其中单个配体， 间隔子和连接子元件快速组合以识别优化的配体，被用作模型 系统的发展新的类别的缓蚀剂，对未来的应用，作为一种通用的方法， 控制细胞通讯和细胞增殖。广泛考虑，这项工作将开发新的方法 了解和控制细胞之间和细胞内的通讯，这在炎症中很重要， 癌症、细菌感染和组织再生。这些方法将有应用程序来理解 疾病的原因以及开发新的有效的疾病治疗方法。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cell proliferation depends on intracellular and extracellular polyvalent interactions. The development of novel approaches to treat diseases requires the development of effectors and inhibitors that exploit the polyvalent basis of numerous processes in cell proliferation. The development of effective polyvalent ligands for proteins, DNA, and cell surfaces requires a multidisciplinary approach that includes the combination of (a) optimized ligands for the individual binding sites; (b) spacer elements capable of highly precisely separating the monovalent ligands for optimized interaction at multiple sites on the target to maximize favorable enthalpy and entropy without introducing the significant entropic or enthalpic penalties commonly observed in polyvalency; and (c) ligation methodologies to link the multiple ligand and spacer elements in a precise manner. In this subproject, we describe a multidisciplinary approach to develop novel peptide-based antagonists of the proliferating cell nuclear antigen (PCNA). PCNA is a trimeric protein that is a master regulator of cell proliferation via its interactions with numerous proteins including the replicative DNA polymerase. The tumor suppressor p21 functions by binding to PCNA and preventing other cellular proteins from accessing PCNA. We are developing approaches to achieve highly effective ligands of PCNA via a multidisciplinary approach that employs the following specific aims: (1) The development of novel PCNA ligands by peptide phage display and from cyclic peptide libraries; (2) the development of assays of PCNA binding and antagonism of DNA polymerase activity; (3) the development of bivalent and trivalent inhibitors of PCNA via the development of novel spacers and linkers capable of optimally placing multiple ligands on PCNA and preventing PCNA interaction with other cellular targets. This approach, in which individual ligand, spacer, and linker elements are rapidly combined to identify optimized ligands, is being used as a model system for the development of new classes of inhibitiors, toward future application as a general approach to control cell communication and cell proliferation. Broadly considered, this work will develop new approaches to understand and control communication between cells and within cells, which is important in inflammation, cancer, bacterial infection, and tissue regeneration. These approaches will have applications to understand the causes of disease and in the development of novel and effective treatments for disease.