XAS ELECTRONIC AND GEOMETRIC STRUCTURAL STUDIES OF COPPER REDOX CENTERS

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。我们建议扩展我们以前对塑性花青素的研究，使用S K-、铜L-和铜K-EDGE和EXAFS光谱相结合的方法来确定含铜电子转移蛋白的电子结构和几何结构。我们的研究的第一部分将集中于了解经典的蓝色铜位和扰动的蓝色铜位之间的差异。一系列天然的和突变的蛋白质，其中轴向配体是系统地变化的，将提供关于轴向配体的作用和控制蓝色铜位置上的氧化还原活性的其他因素的洞察。我们第二部分的研究将集中在细胞色素c氧化酶和一氧化二氮还原酶的CUA中心。我们感兴趣的是确定CuA中基态波函数的性质，定义对位置离域的贡献，以及深入了解配位场对金属-金属键形成的贡献。这将通过在铜K边、S K边和铜L边的各向同性研究以及通过极化的铜K边和S K边的研究来实现。

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. We propose to extend our previous studies on plastocyanin, using a combination of S K-, Cu L-, and Cu K-edge and EXAFS spectroscopies, to define the electronic and geometric structure of Cu-containing electron transfer proteins. The first part of our studies will focus on the understanding the differences between classic blue Cu sites and perturbed blue copper sites. A series of native and mutant proteins, where the axial ligand is systematically varied, will provide insight into the role of the axial ligand and other factors that control redox activity in blue copper sites. The second part of our studies will focus on the CuA center of cytochrome c oxidase and nitrous oxide reductase. We are interested in determining the nature of the ground state wave function in Cu A, defining contributions to the delocalization of the site, and gaining insight into ligand field contributions to metal-metal bond formation. This will be achieved through isotropic studies at the Cu K-, S K-, and Cu L-edge, as well as through polarized Cu K- and S K-edge studies.