DNA RECOGNITION BY BETA TURN PEPTIDES & PEPTIDOMIMETICS

β 转肽的 DNA 识别

• 批准号: 2459521
• 负责人: ERIC C. LONG
• 金额: $ 10.41万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2459521
• 关键词: DNA binding protein; DNA footprinting; antineoplastics; chemical binding; chemical models; circular dichroism; computer simulation; conformation; drug design /synthesis /production; molecular shape; nuclear magnetic resonance spectroscopy; peptide analog; protein structure function

This research plan represents a first step toward the design of artificial DNA-interactive agents based on protein motifs that closely resemble known antitumor drugs. These studies seek, in the long term, to develop molecules with pharmacological properties based on the hypothesis that agents designed to imitate DNA binding proteins may exhibit a targeted bioactivity with diminished cytotoxicity in comparison to conventional natural products that associate with DNA. The following proposal will investigate synthetic analogues of a tandem beta-turn motif found in RNA polymerase II (Tyr-Ser-Pro-Thr-Ser-Pro-Ser-Tyr) that: 1) closely resembles antitumor agents of the quinoxaline class (i.e., triostins and echinomycin); 2) binds to DNA in a fashion similar to bis-intercalating drugs; and 3) exhibits a selectivity for AT-rich DNA regions. Specifically, the proposed studies will attempt to increase the structural integrity and DNA binding affinity of this naturally-occurring motif through strategic substitutions of natural and unnatural amino acids and peptidomimetics that are known to support a type II beta-turn conformation. The modifications to be employed have been chosen to minimally perturb the peptide nature of these structures while also representing a first step toward the development of agents with drug-like stability and protease resistance. The structures of these redesigned motifs will be investigated using 2D NMR, circular dichroism (CD) spectroscopy, and molecular modeling. In parallel, investigations of DNA sequence-selectivity through hydroxyl radical footprinting techniques and evaluations of their mechanism(s) of nucleic acid binding will be carried out to fully develop a model of beta-turn-DNA interaction(s). These studies are particularly interested in correlating motif structure and conformational rigidity to DNA selectivity and helical distortion. This direction represents a novel approach to the rational design of agents that bind to DNA; while most studies in this area have been aimed at redesigning and understanding natural products that interact with DNA, these studies will harness and improve upon the designs utilized by DNA binding proteins.

该研究计划是迈向人工设计的第一步 基于蛋白质基序的DNA相互作用剂，与已知的蛋白质基序非常相似 抗肿瘤药物。从长远来看，这些研究寻求发展 具有药理学特性的分子基于以下假设 旨在模仿DNA结合蛋白的药物可能表现出靶向的 与常规的生物活性和细胞毒性降低 与DNA相关的天然产品。以下建议将 研究RNA中发现的串联β-转变基序的合成类似物 聚合酶II（Tyr-ser-pro-th-ser-pro-ser-tyr）：1）与 Quinoxaline类的抗肿瘤剂（即三位一 eChinomycin）; 2）以类似于双裂的方式与DNA结合 毒品； 3）表现出对富含DNA区域的选择性。 具体而言，拟议的研究将尝试增加结构性 这种天然出现的基序的完整性和DNA结合亲和力 通过自然和不自然氨基酸的战略替代，以及 已知支持II型β-转弯的肽仪 构象。已选择要使用的修改 最小化这些结构的肽性质 代表朝着类似药物的代理开发的第一步 稳定性和抗蛋白酶抗性。这些重新设计的结构 将使用2D NMR，圆形二色性（CD）研究基序 光谱和分子建模。同时，对DNA的研究 通过羟基自由基足迹技术和序列选择性 评估其核酸结合机制的评估 以完全开发β-扭转-DNA相互作用的模型。这些 研究特别感兴趣地关联基序结构和 DNA选择性和螺旋变形的构象刚性。这 方向代表了代理理性设计的一种新颖方法 与DNA结合；虽然该领域的大多数研究都是针对的 重新设计和理解与DNA相互作用的天然产品， 这些研究将利用并改进DNA使用的设计 结合蛋白。