MAGNETIZATION STUDIES OF METALLOPROTEINS

过渡金属离子的交换耦合团簇位于所有 生物化学中的多电子催化事件 贯穿整个氧化还原生物化学。交换耦合的耦合强度 涉及各种金属蛋白中的铁、锰或镍的二聚体将是 研究以实现理解结构的长期目标 以及这些集群的功能。待研究的蛋白质包括： (含铁)：杂氰菊酯、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； (含锰)：假催化酶和锰核苷酸还原酶。SATURA- 将使用SQUID磁感仪收集磁化数据，并 结合EPR和穆斯堡尔谱研究自同样品的产额 这些金属蛋白的磁性的完整描述。 还将研究合适的合成模型。一个具体目标 将扩大结构性信息交流的范围 耦合参数以包括交换耦合所在的小值 小于零场分裂。 *第二个重点将是比较饱和磁化研究 具有单个铁原子的活性中心的金属蛋白 或者是MN。这将利用已知的锰和铜的化学相似性。 Fe和作为对新的饱和磁化技术的检查 与可以应用穆斯堡尔谱的铁进行比较。其目的是 是发展饱和磁化强度来测量磁性 锰金属蛋白。包括在这个项目中的是MN和 铁超氧化物歧化酶和锰、铁双加氧酶。 最后，含有更多的金属蛋白的磁性 包括细胞色素C氧化酶、亚硫酸盐和亚硝酸盐的络合物簇-Re- 将研究导管酶、一氧化碳脱氢酶、镍氢酶和固氮酶。 有格子的。结合EPR和EPR的饱和磁化技术 穆斯堡尔谱学将被开发，以使中间体的研究成为可能 氧化还原态、周转络合物和捕获反应中间体。

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.