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：(申请人提供)表格中的金属多肽 M(II).Xaa-Xaa-His[式中，MU(II)是Ni(II)或Co(III)，Xaa是a-氨基 酸]根据氨基酸的不同，选择性地与DNA相互作用 构图、手性和整体形状。鉴于金属多肽是 由自然使用的相同化学功能组成，以促进 通过抗肿瘤天然产物和蛋白质选择性结合DNA，目标是 该项目旨在开发金属多肽的化学多样性，以更好地 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 目标将通过合成组合肽-配体来实现 文库，使用自然产生的氨基酸和选择非自然的 氨基酸。这些文库将在寡核苷酸结合和 裂解试验用来确定氨基酸的特性，这些氨基酸对 特定的DNA结合位点，并对所有 包括氨基酸。通过上述屏幕获得的信息将被使用 在两个方面：(1)特定DNA位点最好的氨基酸将用于 合成用于结构研究的离散金属多肽(核磁共振，DNA纤维EPR， 和分子模拟)来了解氨基酸-DNA接触 形成的和(2)给定的所有氨基酸的相对排序 结合部位将用来进行比较分子场 分析(CoMFA)/定量构效关系研究以协助从头设计更好的配体 促进特定DNA位点的结合。除了以上几点， Co(II)+的氧活化和DNA识别/修饰活性 Lys-Gly-His将被探索。这种金属多肽可以激活环境中的氧气 (通过形成超过氧二聚体)介导高度选择性的 DNA的修饰。该系统的氧活化将通过以下方式进行评估 O2摄取和过氧化氢释放的量化。S形成的脱氧核糖核酸损伤 这一综合体也将通过使用 寡核苷酸底物。中的碱基修饰和替换 这些DNA底物的金属肽结合部位将被用来 确定促进金属肽识别的DNA结构特征 和反应。Co(II)~(2+)选择性三肽配体的能力 (Lys-Xaa-His&Xaa-Lys-His)在Alternative促进好氧DNA修饰 DNA序列也将进行评估。