XAS AS A NOVEL PROBE OF ELECTRONIC STRUCTURE AND REACTIVITY FOR PROTEIN-BASED SU

该子项目是利用 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。列出的机构是 中心，不一定是研究者的机构。 硫为中心的自由基的基本反应性正在研究在各种肽/蛋白质系统中使用硫K-边X射线吸收光谱（S K-边XAS）作为这些生物重要的肽自由基的电子结构的新探针。半胱氨酰自由基（[CysS？]），它们的亚砜基衍生物（[CysSOn]？）二硫阴离子自由基（[CysS？SCys]1-）已被观察到或假定为若干生物功能中的中间体，包括酶催化、远程电子转移、肽翻译后修饰、细胞氧化还原缓冲、甚至细胞氧化还原信号传导。甲硫基（[MetS？]）被认为参与神经变性疾病途径，例如淀粉样蛋白-β斑块的形成。电子顺磁共振是用于表征自由基物质的主要工具，但这种方法由于硫物质中的自旋轨道加宽而变得复杂。S 3P

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. The basic reactivity of sulfur-centered radicals is being studied in a variety of peptide/protein systems using Sulfur K-edge X-ray Absorption Spectroscopy (S K-edge XAS) as a novel probe of the electronic structure of these biologically-important peptidic radicals. Cysteinyl radicals ([CysS?]), their sulfoxyl derivatives ([CysSOn]?) disulfide anion radicals ([CysS?SCys]1-) have been observed or postulated as intermediates in several biological functions including enzymatic catalysis, long-range electron transfer, peptide post-translational modification, cellular redox buffering, and even cellular redox signaling. Methionine radicals ([MetS?]) are believed to be involved in neurodegenerative diseases pathways such as the formation of amyloid-beta plaques. Electron paramagnetic resonance is the primary tool used for characterization of radical species but this approach is complicated by spin orbit broadening in sulfur species. The S 3p