RESONANCE SPECTROSCOPY OF METALLOPROTEINS

我们的研究重点是与电子有关的铁蛋白。 转移、可逆氧结合和/或酶反应。 具体地说，我们计划研究辣根过氧化物酶，乳过氧化物酶， 霉菌中的氯过氧化物酶和过氧化氢酶 黄微球菌、细胞色素P450CAM和甲酚羟基酶 恶臭假单胞菌，酵母菌的末端细胞色素氧化酶和 来自大肠杆菌的细胞色素d氧化酶、三氯氰菊酯和紫色酸性磷酸酶 来自猪的尿囊液和牛肉的脾。所有这些系统都有一个 含有铁的活性中心，对特定的 蛋白质的功能。我们的目标是阐明这些物质的性质 通过各种物理技术的活动中心并将它们与 生物功能。实验是在密切合作下进行的 生物化学家们正在积极研究这些系统。我们用的是57Fe穆斯堡尔 用光谱学、EPR和Endor探测铁和铜的电子态 它与配体的相互作用。从测量结果的组合来看 在不同的条件下，我们可以表征分子的电子态 在酶循环的不同阶段激活中心，并尝试 对反应机理进行模型化。只要有可能，蛋白质就会被浓缩。 在穆斯堡尔研究中使用了57Fe和其他同位素富集物 用于恩多实验。我们计划将早期的恩多研究扩展到 细胞色素P450CAM到单晶，以深入了解 亚铁血红素复合体。我们还特别感兴趣的是对 观察到半整数和整数自旋系统之间的交换耦合 在过氧化物酶初级化合物的卟啉自由基/铁基络合物中，或 在半甲基红蛋白和紫酸的双核铁配合物中 磷酸酶。

Our research focuses on iron proteins that are involved in electron transfer, reversible oxygen binding and/or enzymatic reactions. Specifically, we plan to study horseradish peroxidase, lactoperoxidase, choloroperoxidase from the mold Caldariomyces fumago, catalase from Micrococcus luteus, cytochrome P450CAM and cresol hydroxylase from Pseudomonas putida, the terminal cytochrome oxidase from yeast and a cytochrome d oxidase from E. coli, hemerythrin, and purple acid phosphatase from pig allantoic fluid and from beef spleen. All these systems have an active center that contains iron and is reponsible for the specific function of the protein. The goal is to elucidate the properties of these active centers by various physical techniques and to correlate them with the biological function. Experiments are done in close collaboration with biochemists actively working on these system. We use 57Fe Mossbauer spectroscopy, EPR and ENDOR to probe the electronic state of the iron and its interaction with ligands. From a combination of measurements taken under different conditions we can characterize the electronic state of the acive center at different stages of the enzymatic cycle and attempt to model the reaction mechanism. Whenever possible the proteins are enriched in 57Fe for the Mossbauer studies, and other isotopic enrichments are used for ENDOR experiments. We plan to extend earlier ENDOR studies on cytochrome P450CAM to single crystals to gain insight into the geometry of the heme complex. We are particularly interested also in the analysis of exchange coupling between half integer and integer spin systems as observed in the porphyrin radical/ferryl complex of peroxidase primary compounds, or in the binuclear iron complexes of semimethemerythrin and purple acid phosphatase.