NMR STUDIES OF BIOMOLECULAR STRUCTURE, FUNCTION, AND DYNAMICS

生物分子结构、功能和动力学的核磁共振研究

• 批准号: 3755451
• 负责人: R LONDON
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3755451
• 关键词: Escherichia coli infections; analytical method; benzene; boric acids; carbon; chemical binding; chemical structure function; conformation; environmental contamination; estrogen receptors; fluorine; galactose; glucose receptor; ligands; macromolecule; molecular dynamics; molecular site; nuclear magnetic resonance spectroscopy; physical chemical interaction; purine nucleoside phosphorylase; stable isotope; subtilisins; tubercidin

The aims of this project are: (1) to develop and modify NMR methodologies for the assignment of resonances and the analysis of the structure and dynamics of molecules in solution, and (2) to apply these methods to problems of concern in relation to environmental health. During the past year, the main emphasis of this project has been on the development of the transferred NOE (TRNOE) technique and its application to the determination of the conformation of the nucleoside drug tubercidin in the complex with E. coli purine nucleoside phosphorylase (PNPase). Several methods were developed to analyze binding kinetics, and dissociation rate constants of 2400 s-1 and 1200 s-1 and 20xC and 10xC, respectively, were determined. Specific deuteration of the 2' position of the inhibitor tubercidin has been carried out in order to reduce or eliminate several important spin diffusion pathways in the inhibitor. Unexpectedly, bound tubercidin was found to correspond to two very different conformations: a major syn conformation and a minor, anticonformation. Ligand competition studies involving tubercidin and 9-deazainosine further suggest that both modes of binding involve interaction with the active sites of the enzyme. Other studies have continued to probe the interaction of benzeneboronic acid (BBA) derivatives with the serine protease subtilisin and with model ligands. In addition to these macromolecular studies, a new approach to editing 1H NMR spectra selectively based on the shifts of scalar coupled carbon-13 nuclei has been evaluated and applied to several model systems. Proton NMR studies were also carried out to determine the structure of corticosterone and deoxycorticosterone metabolites produced by mutated forms of cytochrome P450. A new initiative involving the use of NMR spectroscopy to study structural and conformational aspects of the human estrogen receptor has recently begun.

该项目的目标是：(1) 开发和修改 NMR 方法 用于共振分配和结构分析 溶液中分子的动力学，以及（2）将这些方法应用于 与环境健康有关的问题。 过去期间 今年，该项目的主要重点是开发 转移NOE（TRNOE）技术及其在 核苷类药物结核菌素构象的测定 与大肠杆菌嘌呤核苷磷酸化酶 (PNPase) 形成复合物。 一些 开发了分析结合动力学和解离率的方法 常数分别为 2400 s-1 和 1200 s-1 以及 20xC 和 10xC 决定。 抑制剂 2' 位的特异性氘化 结核菌素的使用是为了减少或消除几种 抑制剂中重要的自旋扩散途径。 没想到，绑定了 发现结核菌素对应于两种截然不同的构象： 主要的顺式构象和次要的反构象。 配体 进一步涉及结核菌素和9-脱氮肌苷的竞争研究 表明两种结合模式都涉及与活性物质的相互作用 酶的位点。 其他研究仍在继续探索 苯硼酸（BBA）衍生物与丝氨酸的相互作用 蛋白酶枯草杆菌蛋白酶和模型配体。 除了这些 大分子研究，编辑 1H NMR 谱的新方法 选择性地基于标量耦合碳 13 原子核的位移 已被评估并应用于多个模型系统。 质子核磁共振研究 还进行了确定皮质酮和 由细胞色素突变形式产生的脱氧皮质酮代谢物 P450。 一项涉及使用核磁共振波谱进行研究的新举措 人类雌激素受体的结构和构象方面 最近开始。