O2 ACTIVATION BY MOSSBAUER SPECTROSCOPY

该提案旨在阐明铁的结构和功能- 含有参与氧活化的蛋白质。 实验 采用的技术是57 Fe穆斯堡尔谱和电子能谱。 顺磁共振 (1)铁氧蛋白甲烷单加氧酶δ 9的研究 去饱和酶、甲苯-4-单加氧酶、核糖核苷酸还原酶和烷烃 羟化酶将继续特别强调的特点 FeII-FeII态的电子结构。 此外，Reaction 中间体将被捕获和研究。 (2)这项研究将得到单核细胞和 双核配合物 (3)许多方面的拟议研究涉及FeIV渗出 状态，或者在酶促反应循环的中间体中，或者作为 合成化合物反应中的瞬态。 该提案提出了一个 系统地研究蛋白质中FeIV的光谱学， 在特别制备的合成复合物中。 (4)异青霉素N合酶的研究将继续进行， 重点在于捕获假定的FeIV中间体。 (5)含有Fe 4S 4簇的胞质乌头酸酶表现出酶促活性， 活动 作为一种脱辅基蛋白，它的功能是与铁反应结合， 转铁蛋白受体和转铁蛋白生物合成中的蛋白质。 那里 是分析证据，证明除了 这些都包含在Fe 4S 4簇中。 它将试图识别和 通过穆斯堡尔谱表征额外的铁。 (6)共价键性质的实验和理论研究 Siroheme与E.大肠杆菌亚硫酸盐 还原酶将通过研究适当连接的合成 组件. (7)模型配合物中反对称交换性质的研究 氰化物抑制的细胞色素氧化酶将继续。 (8)最后，从理论上研究了电子商务的本质， FeIII-FeIV混合价态二聚体的结构将继续进行， 强调探索双交换在化合物中的作用， 低自旋网站。

This proposal seeks to elucidates the structure and function of iron- containing proteins involved in oxygen activation. The experimental techniques employed are 57Fe Mossbauer spectroscopy and electron paramagnetic resonance. (1) Studies of the iron-oxo proteins methane monooxygenase, delta9 desaturase, toluene-4-monooxygenase, ribonucleotide reductase, and alkane hydroxylase will be continued with particular emphasis on characterization of the electronic structures of the FeII-FeII states. Moreover, reaction intermediates will be trapped and studied. (2) This research will be complemented by studies of mononuclear and dinuclear complexes. (3) Many aspects of the proposed research involve the FeIV exudation state, either in intermediates of enzymatic reaction cycles or as transients in reactions of synthetic compounds. This proposal presents a systematic effort to study the spectroscopy of FeIV in proteins as well as in specially prepared synthetic complexes. (4) Studies of isopenicillin N synthase will be continued with special emphasis on trapping putative FeIV intermediates. (5) Cytosolic aconitase containing an Fe4S4 cluster exhibits enzymatic activity. As an apo-protein, it functions as the iron-responsive binding protein in the biosynthesis of transferrin receptor and transferrin. There is analytical evidence for the presence of an extra iron in addition to those contained in the Fe4S4 cluster. It will be attempted to identify and characterize the extra iron by Mossbauer spectroscopy. (6) Experimental and theoretical studies into the nature of the covalent link between the siroheme and the Fe4S4 cluster of E. coli sulfite reductase will be performed by investigating suitably linked synthetic assemblies. (7) Studies into the nature of antisymmetric exchange in model complexes for cyanide-inhibited cytochrome oxidase will be continued. (8) Finally, theoretical studies into the nature of the electronic structure of FeIII-FeIV mixed-valence dimers will be continued, with emphasis on exploring the role of double-exchange in compounds involving low-spin sites.