The Enzymatic Pathway of a Ubiquitin-Like Modification

泛素样修饰的酶途径

• 批准号: 7541369
• 负责人: Yuan Chen
• 金额: $ 36.69万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7541369
• 关键词: Accounting; Active Sites; Amino Acid Sequence; Binding; Binding Sites; Biochemical; Biological Assay; Biological Models; C-terminal; Catalysis; Catalytic Domain; Chemistry; Complex; Conserved Sequence; DNA Repair; Enzymatic Biochemistry; Enzyme Kinetics; Enzymes; Genetic Transcription; Goals; Knowledge; Malignant Neoplasms; Mediating; Modification; Mutation; NMR Spectroscopy; Names; Nature; Nobel Prize; Pathway interactions; Phosphorylation; Post-Translational Protein Processing; Protein translocation; Proteins; Reaction; Recruitment Activity; Regulation; Research Personnel; Role; Scientist; Site; Specificity; Structure; Study Section; Tissues; Ubiquitin; Ubiquitin Like Proteins; Ubiquitination; Variant; chemical reaction; enzyme mechanism; improved; novel; programs; protein complex; therapeutic target; ubiquitin-protein ligase

Ubiquitin-like modifications are similar to other macromolecular chemistry, such as transcription and DMArepair, in that they require multiple steps that are carried out by multi- protein complexes. Better understanding of how the multi-protein machinery catalyzes ubiquitin- like modifications is fundamentally important and will significantly improve our knowledge of how multi-protein complexes carry out macromolecular chemistry. The overall goal of this proposal is to investigate the enzymology of protein modifications by the small ubiquitin-like modifier (SUMO). Sumoylation, which is established as an important post-translational modification, is a good model system for enzymology studies, and has been proposed as a cancer therapeutic target, because of the increased levels of its enzymes in cancers. A mystery about the enzymology is that the binding substrates are too far apart from the catalytic sites in crystal structures to account for catalysis, and the prevailing view is that conformational changes must take place to bring them into close proximity. As shown in our Preliminary Studies section, while the available structures are stable complexes, less stable interactions that have not been characterized are critical to the enzymatic cycle. We will investigate how the weaker interactions may guide substrate translocations to catalytic active sites, and induce allosteric effects in the enzymes. We will use NMR spectroscopy in structural studies, which is especially suitable for characterizing weak protein complexes. Complementary biochemical and enzyme kinetic analysis will be used to identify the role of each interaction in the enzyme mechanism. The proposed studies will likely result in a paradigm shift regarding the enzymes catalyzing ubiquitin-like modifications, and improve our knowledge of the themes and variations of how multi-protein machineries catalyze macromolecular reactions.

泛素样修饰与其他大分子化学相似，例如 转录和 DMArepair，因为它们需要由多方执行的多个步骤 蛋白质复合物。更好地了解多蛋白机制如何催化泛素 类似的修改非常重要，并将显着提高我们对如何进行修改的了解 多蛋白质复合物进行大分子化学。 该提案的总体目标是研究蛋白质修饰的酶学 由小泛素样修饰剂 (SUMO) 修饰。 Sumoylation 被认为是一种重要的 翻译后修饰是酶学研究的良好模型系统，已被 被提议作为癌症治疗靶点，因为其酶水平增加 癌症。酶学的一个谜团是结合底物与底物相距太远。 晶体结构中的催化位点来解释催化作用，普遍的观点是 必须发生构象变化才能使它们更加接近。如我们的 初步研究部分，虽然可用的结构是稳定的复合物，但稳定性较差 尚未表征的相互作用对于酶循环至关重要。我们将 研究较弱的相互作用如何引导底物易位至催化活性 位点，并诱导酶的变构效应。我们将在结构分析中使用核磁共振波谱 研究，特别适合表征弱蛋白质复合物。补充 将使用生化和酶动力学分析来确定每种相互作用在 酶机制。拟议的研究可能会导致关于 催化类泛素修饰的酶，并提高我们对主题和 多蛋白机器催化大分子反应的变化。