Spectroscopic and Magnetic Studies of Metalloprotein Active Sites

在具有不同生物学功能的多种蛋白质中，存在一个偶联的双核非血红素铁活性部位。杂氯菊酯(HR)与O2结合，甲烷单加氧酶激活O2进行羟化，还原的核苷酸还原酶与O2反应生成催化活性的酪氨酸自由基，还原的紫色酸性磷酸酶在磷酸盐存在下被氧化失活。这些蛋白质位点(和类似的模型络合物)可以在三种氧化状态下获得。所罗门博士对这些位置及其底物和小分子结合形式的光谱研究强调了用于探测激发态的吸附、圆二色谱和磁性圆二色谱(MCD)，以及用于探测基态亚能级分裂的变温、变场MCD。这些数据能够确定每个铁的几何结构，以及与桥联连接相关的交换耦合。这项研究的目的是定义与生物活性变化相关的活性部位的几何和电子结构差异。

A coupled binuclear non-heme iron active site exists in a variety of proteins which perform different biological functions. hemerythrin (Hr) binds O2, methane monooxygenase activates it for hydroxylation, reducted ribonucleotide reductase reacts with O2 to generate a catalytically active tyrosyl radical, and reduced purple acid phosphatase is oxidatively inactivated in the presence of phosphate. These protein sites (and analogous model complexes) can be obtained in three oxidation states. Dr. Solomon's spectral studies on these sites and their substrate and small molecule bound forms emphasize bsorption, circular dichrosims, and magnetic circular dichroism (MCD) to probe the excited states, and variable- temperature, variable-field MCD to probe ground state sublevel splittings. This data enables a determination of the geometry of each iron, and the exchange coupling which is associated with bridging ligation. The goal of this research is to define active site geometric and electronic structural diffeences which correlate with variation in biological reactivity.