Metallopeptide-DNA Recognition and Reactivity

金属肽-DNA 识别和反应

• 批准号: 6636602
• 负责人: ERIC C. LONG
• 金额: $ 18.16万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6636602
• 关键词: DNA; DNA binding protein; aminoacid; binding sites; chemical binding; chemical synthesis; cobalt; copper; electron spin resonance spectroscopy; intermolecular interaction; metal complex; metalloproteins; molecular dynamics; molecular shape; nickel; nuclear magnetic resonance spectroscopy; nucleic acid sequence; nucleic acid structure; oligonucleotides; peptide library; surface plasmon resonance

DESCRIPTION: (provided by applicant) Metallopeptides of the form M(II).Xaa-Xaa-His [where MU(II) is Ni(II) or Co(III) and Xaa is an a-amino acid] interact selectively with DNA as a function of their amino acid composition, chirality and overall shape. Given that metallopeptides are composed of the same chemical functionalities used by Nature to promote selective DNA binding by anti-tumor natural products and proteins, the goal of this project is to exploit the chemical diversity of metallopeptides to better understand the recognition activities of natural DNA binding agents and to generate model compounds with efficient and selective binding properties. These goals will be pursued through the synthesis of combinatorial peptide-ligand libraries, using both naturally occurring amino acids and select unnatural amino acids. These libraries will be screened in oligonucleotide binding and cleavage assays to determine the identity of amino acids that are best for a particular DNA binding site and to rank quantitatively the ability of all the amino acids included. Information gained through the above screen will be used in two ways: (1) the best amino acids for a particular DNA site will be used to synthesize discrete metallopeptides for structural studies (NMR, DNA fiber EPR, and molecular modeling) to understand the amino acid-DNA contacts that are formed and (2) the relative rank-ordering of all amino acids for a given binding site will be used to carry out a comparative molecular field analysis(CoMFA)/QSAR study to assist in the de novo design of better ligands that promote the binding of select DNA sites. In addition to the above, the oxygen activation & DNA recognition/modification activities of Co(II) + Lys-Gly-His will be explored. This metallopeptide can activate ambient dioxygen (through the formation of a u-peroxo dimer) to mediate the highly selective modification of DNA. Oxygen activation by this system will be evaluated through a quantification of 02 uptake and peroxide release. The DNA lesion(s) formed by this complex will also be identified and characterized through the use of oligonucleotide substrates. Nucleobase modifications and substitutions within the metallopeptide binding site of these same DNA substrates will be used to determine the DNA structural features that promote metallopeptide recognition and reaction. The ability of Co(II) + alternative tripeptide ligands (Lys-Xaa-His & Xaa-Lys-His) to promote aerobic DNA modification at alternative DNA sequences will also be evaluated.

描述：（由申请人提供）形式的金属肽 M(II).Xaa-Xaa-His [其中 MU(II) 是 Ni(II) 或 Co(III)，Xaa 是 a-氨基 酸]根据其氨基酸选择性地与 DNA 相互作用 成分、手性和整体形状。鉴于金属肽是 由与大自然所使用的相同化学功能组成，以促进 抗肿瘤天然产物和蛋白质选择性结合 DNA，其目标 该项目旨在利用金属肽的化学多样性来更好地 了解天然 DNA 结合剂的识别活性并 生成具有高效和选择性结合特性的模型化合物。这些 将通过组合肽-配体的合成来实现目标 文库，使用天然存在的氨基酸并选择非天然的氨基酸 氨基酸。这些文库将在寡核苷酸结合中进行筛选 裂解测定以确定最适合的氨基酸的身份 特定的 DNA 结合位点并对所有结合位点的能力进行定量排名 包括氨基酸。通过上述屏幕获得的信息将被使用 有两种方式：（1）特定 DNA 位点的最佳氨基酸将被用于 合成离散金属肽用于结构研究（NMR、DNA 纤维 EPR、 和分子建模）来了解氨基酸-DNA 接触 形成和（2）给定的所有氨基酸的相对排序 结合位点将用于进行分子领域的比较 分析（CoMFA）/QSAR 研究，协助从头设计更好的配体 促进选定 DNA 位点的结合。除上述内容外， Co(II) + 的氧活化和 DNA 识别/修饰活性 Lys-Gly-His 将被探索。这种金属肽可以激活环境中的分子氧 （通过形成u-过氧二聚体）介导高度选择性 DNA 的修饰。该系统的氧气活化将通过以下方式进行评估 O 2 吸收和过氧化物释放的量化。 DNA 损伤由 该复合体也将通过使用来识别和表征 寡核苷酸底物。内的核碱基修饰和取代 这些相同 DNA 底物的金属肽结合位点将用于 确定促进金属肽识别的 DNA 结构特征 和反应。 Co(II) + 替代三肽配体的能力 （Lys-Xaa-His 和 Xaa-Lys-His）促进有氧 DNA 修饰 DNA 序列也将被评估。