Metallopeptide-DNA Recognition and Reactivity

描述：（由申请人提供）以下形式的金属肽 M（II）.Xaa-Xaa-His [其中MU（II）是Ni（II）或Co（III）且Xaa是α-氨基 氨基酸]作为其氨基酸的功能选择性地与DNA相互作用 组成、手性和整体形状。鉴于金属肽是 由自然界用来促进 抗肿瘤天然产物和蛋白质的选择性DNA结合， 该项目旨在利用金属肽的化学多样性， 了解天然DNA结合剂的识别活性， 产生具有有效和选择性结合性质的模型化合物。这些 目标将通过合成组合肽-配体来实现 文库，使用天然存在的氨基酸和选择的非天然氨基酸， 个氨基酸这些文库将在寡核苷酸结合中筛选， 切割测定以确定最适合于本发明的氨基酸的同一性。 特定的DNA结合位点，并定量排名的能力，所有的 包括氨基酸。通过上述屏幕获得的信息将用于 （1）特定DNA位点的最佳氨基酸将用于 合成用于结构研究（NMR，DNA纤维EPR， 和分子建模）来了解氨基酸-DNA接触， 形成和（2）相对排名排序的所有氨基酸的给定 结合位点将用于进行比较分子领域 分析（CoMFA）/QSAR研究，以协助从头设计更好的配体 促进特定DNA位点的结合。除上述内容外， Co（II）+的氧活化和DNA识别/修饰活性 将探索Lys-Gly-His。这种金属肽可以激活周围的分子氧 （通过形成u-过氧二聚体）介导高选择性的 DNA的改变。该系统的氧活化将通过以下方式进行评估： O2吸收和过氧化物释放的定量。DNA损伤形成于 该复合体也将通过使用 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 & Xaa-Lys-His）以促进交替的需氧DNA修饰 还将评估DNA序列。

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.