CHARACTERIZATION OF THE STRUCTURE OF A LEAD-DEPENDENT DNAZYME

铅依赖性脱氧核糖核酸酶的结构表征

• 批准号: 7722004
• 负责人: GERARD C WONG
• 金额: $ 0.31万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7722004
• 关键词: 3-Dimensional; Adopted; Binding; Binding Sites; Buffers; Catalytic DNA; Catalytic Domain; Chemicals; Complex; Computer Retrieval of Information on Scientific Projects Database; Condition; Dependence; Environment; Fluorescence Resonance Energy Transfer; Funding; Grant; Institution; Ions; Knowledge; Metals; Process; Research; Research Personnel; Resources; Sodium Chloride; Source; Structure; System; United States National Institutes of Health; cofactor; lead concentration; lead ion; three dimensional structure

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have previously characterized the structure of the 17E DNAzyme using Fluorescence Resonance Energy Transfer (FRET). This study revealed that in the presence of Zn2+ the DNAzyme undergoes a two-step folding process in order to adopt a more compact structure. We propose to use EXAFS to further study the three-dimensional structure of the 17E catalytic core when bound to Pb2+. Pb has core-shell levels that are accessible using EXAFS. The catalytic activity of the Pb DNAzyme and the dependence of activity on Pb concentration and buffer conditions have been thoroughly characterized. The chemical environment around the Pb binding site is expected to be complex. However, spatial correlations in complex, noncrystalline systems are routinely studied using EXAFS. We intend to investigate the EXAFS of Pb in order to determine the distances between the Pb metal ion cofactor and key atoms in the DNAzyme catalytic core. The DNAzyme structure will be investigated as a function of Pb concentration, monovalent salt concentration, and pH. This 3-D information will then be combined with existing knowledge of the sequence and structure of the DNAzyme in order to form a better understanding of the functional structure of the DNAzyme.

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们以前已经用荧光共振能量转移(FRET)表征了17E DNAzyme的结构。本研究表明，在锌离子存在下，DNAzyme经历了两步折叠过程，以采用更紧密的结构。我们建议用EXAFS进一步研究17E催化核与Pb2+结合时的三维结构。PB具有可使用EXAFS访问的核心-外壳级别。对铅脱氧核酶的催化活性以及活性与铅浓度和缓冲条件的依赖关系进行了详细的表征。铅结合部位周围的化学环境预计将是复杂的。然而，复杂的非晶态系统中的空间关联通常是用EXAFS来研究的。我们打算研究铅的EXAFS，以确定铅金属离子辅因子与DNAzyme催化核心中关键原子之间的距离。DNAzyme的结构将作为铅浓度、单价盐浓度和pH的函数进行研究。然后，这些三维信息将与现有的DNA酶序列和结构知识结合起来，以便更好地理解DNA酶的功能结构。