Chemistry and Mechanism of Direct DNA Repair Proteins

DNA直接修复蛋白的化学和机制

• 批准号: 7911190
• 负责人: CHUAN HE
• 金额: $ 11.59万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7911190
• 关键词: Abdominal colic; Alkylating Agents; Alkylation; Base Pairing; Binding; Biochemical; Cell Extracts; Chemicals; Chemistry; Complex; DNA; DNA Binding; DNA Damage; DNA Probes; DNA Repair; DNA alkyltransferase; DNA lesion; DNA repair protein; DNA-Protein Interaction; Dealkylation; Development; Disease; Escherichia; Family; Genetic; Genome; Goals; Homologous Gene; Human; Human Activities; Iron; Knowledge; Lead; Lesion; Malignant Neoplasms; Methods; Modeling; Modification; Mutation; O(6)-Methylguanine-DNA Methyltransferase; Organism; Play; Protein Biochemistry; Protein Family; Proteins; RNA; Research; Research Personnel; Resistance; Role; Single-Stranded DNA; Structure; System; Techniques; Testing; X-Ray Crystallography; anticancer treatment; base; cancer cell; chemical synthesis; chemotherapeutic agent; chemotherapy; crosslink; design; ds-DNA; extracellular; improved; inhibitor/antagonist; interest; killings; link protein; macromolecule; novel; preference; programs; repaired; success; tumor

DESCRIPTION (provided by applicant): Accumulation of genetic changes due to the presence of unrepaired DNA lesions can lead to the development of cancer and other diseases. Almost all organisms have evolved delicate systems to locate and repair these DNA lesions. This research program aims to understand the fundamental mechanisms of two direct DNA dealkylation repair protein families. Chemical synthesis, protein biochemistry, macromolecule X-ray crystallography, and various spectroscopic/physical techniques will be employed to elucidate the mechanism of the DNA base repair proteins O6-alkyguanine-DNA alkyltransferases (AGT) and AlkB. These proteins play vital roles in protecting genome integrity. The repair activity of the human AGT protein is also a major factor in tumor resistance to various alkylating chemotherapies. AlkB represents a new type of DNA repair function that has just been discovered. This family of proteins repairs alkylated base lesions by using a novel oxidative dealkylation mechanism. The structure and mechanism of the bacterial and human AlkB proteins remain mostly unknown. Both AGT and AlkB form unstable complexes with DNA, which significantly hampers efforts to characterize the protein/DNA interaction of these proteins. Proposed here are chemical strategies to stabilize or trap both specific and non-specific protein/DNA complexes of AGT and AlkB for structural characterization. DNA probes have been designed which will be synthesized and used to study the mechanism of AlkB. Various physical and biochemical methods will be employed to characterize the iron(ll) centers of AlkB. Our goal is to fully elucidate the damage-searching, -recognition and -repair mechanisms of these proteins. In addition, more potent inhibitors will be developed for human AGT, a proven target for improving the efficiency of anticancer treatments. The success of this research program will significantly advance the understanding of these two protein families and provide general mechanistic implications for other repair systems.

描述（由申请人提供）： 由于未修复的 DNA 损伤而导致的基因变化的积累可能导致癌症和其他疾病的发生。几乎所有生物体都进化出了精密的系统来定位和修复这些 DNA 损伤。该研究项目旨在了解两个直接 DNA 脱烷基修复蛋白家族的基本机制。将采用化学合成、蛋白质生物化学、高分子X射线晶体学和各种光谱/物理技术来阐明DNA碱基修复蛋白O6-烷基鸟嘌呤-DNA烷基转移酶(AGT)和AlkB的机制。这些蛋白质在保护基因组完整性方面发挥着至关重要的作用。人AGT蛋白的修复活性也是肿瘤对各种烷化化疗产生耐药性的主要因素。 AlkB代表了一种刚刚被发现的新型DNA修复功能。该蛋白质家族通过使用新型氧化脱烷基化机制来修复烷基化碱基损伤。细菌和人类 AlkB 蛋白的结构和机制仍然未知。 AGT 和 AlkB 都与 DNA 形成不稳定的复合物，这极大地阻碍了表征这些蛋白质的蛋白质/DNA 相互作用的努力。这里提出了稳定或捕获 AGT 和 AlkB 的特异性和非特异性蛋白质/DNA 复合物的化学策略，以进行结构表征。 DNA探针已被设计，将被合成并用于研究AlkB的机制。将采用各种物理和生化方法来表征 AlkB 的铁 (II) 中心。我们的目标是充分阐明这些蛋白质的损伤搜索、识别和修复机制。此外，还将开发针对人类 AGT 的更有效的抑制剂，AGT 是提高抗癌治疗效率的经过验证的目标。该研究计划的成功将显着增进对这两个蛋白质家族的理解，并为其他修复系统提供一般机制的影响。