MAGNETIZATION STUDIES OF METALLOPROTEINS

过渡金属离子的交换耦合簇位于所有 生物化学中的多电子催化事件， 贯穿于氧化还原生物化学中。 交换耦合的耦合强度 在各种金属蛋白中涉及Fe、Mn或Ni的二聚体将是 为了实现理解结构的长期目标， 和这些集群的功能。 待研究的蛋白质包括： （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;（含镍）：尿素酶和甲基-CoM还原酶; （含Mn）：假过氧化氢酶和Mn核糖核苷酸还原酶。 土星- 将使用SQUID磁强计收集离子磁化数据， 结合EPR和穆斯堡尔研究的自我相同的样品， 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 将扩大结构信息交换的范围， 耦合参数，包括交换耦合 小于零场分裂。 * 第二个重点将是比较饱和磁化研究 金属蛋白具有活性部位，其中单个原子为Fe或 或Mn。 这将利用Mn和Mn的化学性质中已知的相似性。 铁和作为检查新的饱和磁化技术， 与Fe相比，可以应用穆斯堡尔谱。 目的 是发展饱和磁化强度来测量磁性 锰金属蛋白。 该项目将包括Mn和 Fe超氧化物歧化酶和Mn和Fe双加氧酶。 最后，含有更多金属蛋白的磁性 包括细胞色素c氧化酶、亚硫酸盐和亚硝酸盐的复杂簇， 将研究乳糖酶、CO脱氢酶、Ni氢化酶和固氮酶。 激动 饱和磁化技术结合EPR和 穆斯堡尔谱将被开发，以使研究中间 氧化还原态、周转络合物和捕获的反应中间体。

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.