IRON K-EDGE XAS STUDIES OF NON-HEME IRON ENZYMES, INTERMEDIATES, AND MODEL SYSTE

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 在蛋白质研究中，特别是对于反应中间体，有几种情况下，光谱方法，如共振拉曼，EPR，UV-vis，和MCD不能提供一个完整的图片的电子和几何结构的活性位点。在这种情况下，就像许多非血红素铁酶的情况一样，使用Fe-K XAS边缘和EXAFS技术可以提供关键信息。Fe的K边分析可以解决模糊的氧化态和细化金属配位，EXAFS可以澄清配体排列，键长和整体配位范围。为了了解配位环境如何影响酶活性位点的电子结构以及机械营业额，我们特别建议将XAS与我们的其他光谱技术相结合，以了解几种非血红素铁酶，模型系统和反应中间体的活性位点。特别感兴趣的系统包括：酪氨酸羟化酶，卤化酶，Rieske双加氧酶，intradiol双加氧酶，几个{FeNO}7类似物，模型配合物的FeIV=O系统，和双核铁系统？因为费利？在核糖核苷酸还原酶的活性位点的多肽。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In the study of proteins, in particular for reaction intermediates, there are several cases in which spectroscopic methods such as resonance Raman, EPR, UV-vis, and MCD are unable provide a complete picture of the electronic and geometric structure of the active site. In such situations, as is the case for many non-heme iron enzymes, the use of Fe-K XAS edge and EXAFS techniques can provide crucial information. Fe K-edge analysis can resolve ambiguous oxidation states and refine metal coordination, and EXAFS can clarify ligand arrangement, bond length, and the overall coordination sphere. In order to understand how coordination environment affects electronic structure of enzymatic active sites as well as mechanistic turnover, we propose specifically to integrate XAS with our other spectroscopic techniques in order to understand the active sites of several non-heme iron enzymes, model systems, and reaction intermediates. Systems of specific interest include: tyrosine hydroxylase, halogenases, Rieske dioxygenases, intradiol dioxygenases, several {FeNO}7 analogs, model complexes of FeIV=O systems, and the binuclear iron systems of ?due ferri? polypeptides for the active site in ribonucleotide reductases.