O2 ACTIVATION BY MOSSBAUER SPECTROSCOPY

拟议的研究旨在阐明其结构和功能 含铁蛋白质。 还建议探索电子化 模仿结构特征的合成配合物的结构 在蛋白质中观察到的金属中心。 实验技术 采用的是 57Fe 穆斯堡尔谱和电子顺磁 共振（EPR）。 (1) 铁氧蛋白甲烷双核簇的研究 单加氧酶和核糖核苷酸还原酶将继续，重点是 FeIIFeII簇形式和中间体的电子结构 的氧反应。 (2) 本研究将得到同核和 铁氧蛋白的异核模型复合物。 (3) 穆斯堡尔测量探索结构和化学 嗜热栖热菌细胞色素 ba3 的双氧还原位点 将继续。 将努力表征电子 耦合细胞色素 a3/CuB 位点的结构并寻找 催化反应的中间体。 (4) 最近开始的新型 FeIV 配合物的研究将继续进行 扩大了。 (5) 还建议研究含有 Fe 的配合物 或通过桥连配体连接到 Fe4S4 簇的 Ni 位点。 这样的 复合物是大肠杆菌亚硫酸盐活性位点的有趣模型 还原酶，或许还有 CO 脱氢酶。 (6) CO脱氢酶和异青霉素N合酶的研究 继续。 (7) 最后，我们将继续开发整数自旋EPR，目标是 进一步改进这项新技术的定量方面。

The research proposed seeks to elucidate the structure and function of iron-containing proteins. It is also proposed to explore the electronic structure of synthetic complexes which mimick structural features of the metal centers observed in the proteins. The experimental techniques employed are 57Fe Mossbauer spectroscopy and Electron Paramagnetic Resonance (EPR). (1) Studies of the binuclear clusters of the iron-oxo proteins methane monooxygenase and ribonucleotide reductase will be continued, with focus on the electronic structure of the FeIIFeII cluster forms and intermediates of the oxygen reactions. (2) This research will be complemented by studies of homonuclear and heteronuclear model complexes of iron-oxo proteins. (3) Mossbauer measurements to explore the structure and chemistry of the dioxygen reduction site of cytochrome ba3 from Thermus thermophilus will be continued. Efforts will be made to characterize the electronic structure of the coupled cytochrome a3/CuB site and to search for intermediates of the catalytic reaction. (4) Recently begun studies of novel FeIV complexes will be continued and expanded. (5) It is also proposed to study complexes which contain either an Fe or a Ni site linked by a bridging ligand to an Fe4S4 cluster. Such complexes are interesting models for the active sites of E. coli sulfite reductase and, perhaps, CO dehydrogenase. (6) Studies of CO dehydrogenase and isopenicillin N synthase will be continued. (7) Finally, we will continue to develop integer spin EPR with the goal of further improving the quantitative aspects of this new technique.