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

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 用硫K边X射线吸收光谱(S K边XAS)作为一种新的探针，研究了硫心自由基在多种多肽/蛋白质体系中的基本反应性，作为一种新的探针来研究这些具有重要生物意义的肽类自由基的电子结构。半胱氨基自由基([CysS？])及其亚砜基衍生物([CysSOn]？)二硫键阴离子自由基([CysS？SCys]1-)被观察到或推测为多种生物学功能的中间体，包括酶催化、远程电子传递、多肽翻译后修饰、细胞氧化还原缓冲，甚至细胞氧化还原信号转导。蛋氨酸自由基([Mets？])据信参与了神经退行性疾病的途径，如淀粉样β斑块的形成。电子顺磁共振是表征自由基物种的主要工具，但硫物种的自旋轨道展宽使这种方法变得复杂。《S》第三集

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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