MAGNETIZATION STUDIES OF METALLOPROTEINS

金属蛋白质的磁化研究

• 批准号: 3281189
• 负责人: EDMUND P DAY
• 金额: $ 21.25万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-12-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3281189
• 关键词: Escherichia coli; Mossbauer spectrometry; biomagnetism measurement; catalase; chemical models; circular magnetic dichroism; cytochrome oxidase; electron spin resonance spectroscopy; hemerythrin; iron; magnetism; manganese; metalloproteins; methane monooxygenase; nickel; nitrogenase; ribonucleotide reductase; sulfite reductase; superoxide dismutase; urease

Exchange coupled clusters of transition metal ions lie at the heart of all multi-electron catalytic events in biochemistry and are prevalent throughout redox biochemistry. The coupling strengths of exchange coupled dimers involving Fe, Mn or Ni in a variety of metalloproteins will be studied to accomplish the long range goal of understanding the structure and function of these clusters. The proteins to be studied include: (Fe-containing): hemerythrin, uteroferrin, ribonucleotide reductase and methane monooxygenase; (Ni-containing): urease and methyl-CoM reductase; (Mn-containing): pseudocatalase and Mn ribonucleotide reductase. Satura- tion magnetization data will be collected using a SQUID susceptometer and combined with EPR and Mossbauer studies of the self-same sample to yield complete description of the magnetic properties of these metalloproteins. Appropriate synthetic models will be studied as well. One specific goal will be to extend the range of the structurally informative exchange coupling parameter to include small values where the exchange coupling is less than the zero field splitting. * A second focus will be comparative saturation magnetization studies of metalloproteins having an active site with a single atom of either Fe or Mn. This will exploit the known similarities in the chemistry of Mn and Fe and serve as a check on the new saturation magnetization technique by comparison with Fe where Mossbauer spectroscopy can be applied. The aim is to develop saturation magnetization to measure the magnetic properties of manganese metalloproteins. Included in this project will be both Mn and Fe superoxide dismutases and Mn and Fe dioxygenases. Finally, the magnetic properties of metalloproteins containing more complex clusters including cytochrome c oxidase, sulfite and nitrite re- ductase, CO dehydrogenase, Ni hydrogenase, and nitrogenase will be inves- tigated. Saturation magnetization techniques in combination with EPR and Mossbauer spectroscopies will be developed to enable study of intermediate redox states, turnover complexes, and trapped reaction intermediates.

过渡金属离子的交换耦合簇是所有这些的核心 生物化学中的多电子催化事件很普遍 整个氧化还原生物化学。 交换耦合的耦合强度 多种金属蛋白中涉及 Fe、Mn 或 Ni 的二聚体将 研究以实现理解结构的长期目标 以及这些簇的功能。 要研究的蛋白质包括： （含铁）：血红蛋白、子宫铁蛋白、核糖核苷酸还原酶和 甲烷单加氧酶； (含Ni)：脲酶和甲基-CoM还原酶； (含Mn)：假过氧化氢酶和Mn核糖核苷酸还原酶。 饱和度- 化磁化数据将使用 SQUID 磁感应计收集 结合同一样品的 EPR 和穆斯堡尔研究得出 这些金属蛋白的磁性的完整描述。 还将研究适当的合成模型。一个具体目标 将扩大结构性信息交换的范围 耦合参数包括交换耦合处的小值 小于零场分裂。 * 第二个重点是比较饱和磁化强度研究 具有单个 Fe 原子活性位点的金属蛋白 或锰。 这将利用 Mn 和 Fe 并作为对新饱和磁化技术的检查 与可以应用穆斯堡尔光谱的 Fe 进行比较。 目的 是开发饱和磁化强度来测量磁性能 锰金属蛋白。 该项目将包括锰和 Fe 超氧化物歧化酶以及 Mn 和 Fe 双加氧酶。 最后，含有更多金属蛋白的磁性 复杂的簇，包括细胞色素c氧化酶、亚硫酸盐和亚硝酸盐重新 将研究导管酶、CO 脱氢酶、Ni 氢化酶和固氮酶 提起来。 饱和磁化技术与 EPR 相结合 将开发穆斯堡尔光谱以实现中间体的研究 氧化还原态、转换络合物和捕获的反应中间体。