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.

这项研究计划代表了设计人工智能的第一步 基于蛋白质基序的DNA相互作用剂， 抗肿瘤药物从长远来看，这些研究旨在发展 具有药理学性质的分子，其假设是， 被设计为模仿DNA结合蛋白的试剂可以表现出靶向的 生物活性，与常规方法相比细胞毒性降低 与DNA相关的天然产物。以下建议将 研究RNA中发现串联β-转角基序的合成类似物 聚合酶II（Tyr-Ser-Pro-Thr-Ser-Pro-Ser-Tyr）：1）与 喹喔啉类的抗肿瘤剂（即，曲奥斯汀和 棘霉素）; 2）以类似于双嵌入的方式与DNA结合 药物;和3）表现出对富含AT的DNA区域的选择性。 具体而言，拟议的研究将试图增加结构性 这种天然存在基序的完整性和DNA结合亲和力 通过天然和非天然氨基酸的策略性取代， 已知支持II型β-转角的肽模拟物 构象所选择的修改是为了 最小程度地干扰这些结构的肽性质， 这代表了开发具有药物样活性的药物的第一步， 稳定性和蛋白酶抗性。这些重新设计的结构 基序将使用2D NMR，圆二色性（CD） 光谱学和分子建模。与此同时，对DNA的研究 通过羟基自由基足迹技术的序列选择性， 将进行它们的核酸结合机制的评价 完全开发出一个β-turn-DNA相互作用的模型。这些 研究特别感兴趣的是相关的基序结构， 构象刚性对DNA选择性和螺旋扭曲的影响。这 方向代表了一种合理设计代理的新方法 与DNA结合;虽然这一领域的大多数研究都是针对 重新设计和理解与DNA相互作用的天然产物， 这些研究将利用和改进DNA利用的设计， 结合蛋白