EPR and Mossbauer Characterization of Mn and Fe Proteins, Models, Intermediates

描述（由申请人提供）：锰蛋白和酶在多种生物功能中都很重要。锰在人体中的相对含量和分布是已知的，然而，由于锰的结合相对较弱，锰影响人类健康的机制现在才刚刚开始被阐明。锰在真核生物和原核生物的许多细胞过程中发挥着重要作用。本提案将研究两种单核锰酶（双加氧酶和丙酮羧化酶），因为它们具有独特的底物激活机制。此外，金属传输和调节系统也是一个不断发展的研究领域。最近，Mn 转运调节蛋白 (MntR) 的结构特征表明其具有双核 Mn 位点。将研究 MntR 中 Mn 中心的光谱表征以及它如何识别 DNA 响应 Mn。单核和双核 Mn 中心 EPR 谱解释的根本性进步将带来前所未有的能力来定量表征蛋白质和酶的活性 Mn 位点。这将应用于上述蛋白质，也可用于双核 Mn 酶噬菌体 lambda 磷酸酶的表征。通过仿生复合物的研究，可以深入了解锰和铁酶激活氧和氮的机制。此类机制中中间体的检测和表征对于理解该机制至关重要。将表征两个不同家族的仿生复合物及其氧或氮衍生中间体。

DESCRIPTION (provided by applicant): Manganese proteins and enzymes are important in a diverse range of biological functions. The relative amounts and distribution of Mn in humans is known, however, due to the relatively weak binding of Mn, the mechanisms by which Mn can affect human health are only now beginning to be unraveled. Manganese plays an essential role in many cellular processes of both eukaryotes and prokaryotes. Two mononuclear Mn enzymes (Dioxygenase and Acetone Carboxylase) will be investigated in this proposal due to their unique mechanisms of substrate activation. In addition, metal transport and regulation systems are a growing area of study. Recently, a Mn transport regulatory protein (MntR) has been structurally characterized to show a dinuclear Mn site. A spectroscopic characterization of the Mn centers in MntR and how it recognizes DNA in response to Mn will be investigated. A fundamental advance in the interpretation of EPR spectra for both mono- and dinuclear Mn centers will allow an unprecedented ability to quantitatively characterize the active Mn sites of proteins and enzymes. This will be applied to the above proteins, and also for a characterization of the dinuclear Mn enzyme Bacteriophage lambda-Phosphatase. Insight into the mechanism of oxygen and nitrogen activation by Mn and Fe enzymes will be derived from studies of biomimetic complexes. The detection and characterization of intermediates in such mechanisms is critical for an understanding of the mechanism. Two different families of biomimetic complexes and their oxygen or nitrogen derived intermediates will be characterized.