RESONANCE SPECTROSCOPY OF METALLOPROTEINS

金属蛋白的共振光谱

• 批准号: 3268916
• 负责人: PETER G DEBRUNNER
• 金额: $ 12.82万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-01-01 至 1987-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3268916
• 关键词: Escherichia coli; Mossbauer spectrometry; catalase; chemical structure function; cytochrome P450; cytochrome c; cytochrome oxidase; electron spin resonance spectroscopy; electron transport; enzyme complex; enzyme structure; hemoglobin; hemoprotein; ligands; mathematical model; metalloproteins; molecular orbital; myoglobin; nitrites; oxidoreductase; oxygen transport; peroxidases; thermodynamics

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.

我们的研究主要集中在铁蛋白，涉及电子 转移、可逆氧结合和/或酶促反应。 具体来说，我们计划研究辣根过氧化物酶，乳过氧化物酶， 来自烟状卡尔达酵母的氯过氧化物酶，来自 藤黄微球菌、细胞色素P450 CAM和甲酚羟化酶 恶臭假单胞菌，末端细胞色素氧化酶从酵母和一个 细胞色素d氧化酶。大肠杆菌、血红蛋白和紫色酸性磷酸酶 猪尿囊液和牛脾中提取。 所有这些系统都有一个 活性中心，含有铁，并负责特定的 蛋白质的功能。 我们的目标是阐明这些性质 活动中心的各种物理技术，并将它们与 生物功能。 实验是在与 生物化学家们正在积极研究这些系统。 我们使用57 Fe穆斯堡尔谱 光谱，EPR和ENDOR来探测铁的电子状态， 与配体的相互作用。 从综合的测量结果来看 在不同的条件下，我们可以表征的电子状态的 活性中心在不同阶段的酶循环，并试图 模拟反应机制。 只要有可能， 用于穆斯堡尔研究的57 Fe，以及其他同位素富集 ENDOR实验。 我们计划将早期的ENDOR研究扩展到 细胞色素P450 CAM的单晶，以深入了解的几何形状， 血红素复合体 我们还特别感兴趣的分析， 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基/铁基复合物中，或 在半甲氰菊酯和紫酸的双核铁络合物中， 磷酸酶。