DNA RECOGNITION BY BETA TURN PEPTIDES & PEPTIDOMIMETICS

β 转肽的 DNA 识别

• 批准号: 2188472
• 负责人: ERIC C. LONG
• 金额: $ 10.01万
• 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/2188472
• 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人工智能设计的第一步。 基于与已知蛋白质非常相似的蛋白质基序的DNA相互作用试剂 抗肿瘤药物。从长远来看，这些研究寻求发展 具有药理特性的分子，其基础假设是 设计用来模拟DNA结合蛋白的药物可能会显示出靶向 与常规方法相比，细胞毒性降低的生物活性 与DNA有关的天然产物。以下提案将 研究在RNA中发现的串联β转角基序的合成类似物 聚合酶II(Tyr-Ser-Pro-Thr-Ser-Pro-Ser-Tyr)：1)非常相似 喹恶啉类抗肿瘤药物(即Triostins和 棘霉素)；2)以类似于双嵌插的方式与DNA结合 药物；以及3)对富含AT的DNA区域表现出选择性。 具体地说，拟议的研究将尝试增加结构 这个自然产生的基序的完整性和DNA结合亲和力 通过战略替代天然和非天然氨基酸和 已知支持II型Beta-Turn的多肽类药物 构象。将采用的修改已被选择为 最小限度地干扰这些结构的多肽性质，同时还 代表着朝着开发具有类药物的药物迈出的第一步 稳定性和耐酶活性。这些重新设计的结构 模体将用2D核磁共振、圆二色谱(CD)进行研究 光谱学和分子建模。同时，对DNA的研究 通过羟基足迹技术和 将对它们的核酸结合机制(S)进行评估 完全发展了一个β-转体-脱氧核糖核酸相互作用模型(S)。这些 研究特别感兴趣的是基序结构和 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智能体的新方法 它与DNA结合；而这一领域的大多数研究都是针对 重新设计和理解与DNA相互作用的天然产品， 这些研究将利用和改进DNA所利用的设计 结合蛋白。