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

XAS 作为蛋白质 SU 电子结构和反应性的新型探针

• 批准号: 7721804
• 负责人: PIERRE KENNEPOHL
• 金额: $ 0.38万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7721804
• 关键词: Anions; Biological; Biological Process; Buffers; Catalysis; Computer Retrieval of Information on Scientific Projects Database; Disulfides; Effectiveness; Electron Spin Resonance Spectroscopy; Electron Transport; Electronics; Electrons; Environment; Funding; Goals; Grant; Hydrogen Bonding; Institution; Ocular orbit; Oxidation-Reduction; Peptides; Post-Translational Protein Processing; Proteins; Range; Research; Research Personnel; Resources; Roentgen Rays; Signal Transduction; Source; Spectrum Analysis; Structure; Sulfur; System; United States National Institutes of Health; absorption; base; novel; tool

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 different protein environments using Sulfur K-edge X-ray Absorption Spectroscopy as a novel probe of the electronic structure of these biologically-important peptidic radicals. Cysteinyl radicals ([Cys¿]) and 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. Electron paramagnetic resonance has been the primary tool used to characterize these radical species but direct observation is compromised by spin-orbit broadening of the signals, which has diminished the effectiveness of the approach. The S 1s->3p pre-edge transition that results from radical character on a sulfur atom is being used to directly probe the electronic structure of these radical species and to investigate the effect of factors such as hydrogen bonding and electron delocalization on the reactivity of these radicals in various protein environments. An important goal of this effort is to develop S K-edge XAS as a powerful and general probe of sulfur radical species to investigate a wide range of biological systems.

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 用硫K边X射线吸收光谱作为一种新的探针来研究这些具有生物重要性的多肽自由基的电子结构，研究了这些以硫为中心的自由基在各种不同的蛋白质环境中的基本反应活性。半胱氨基自由基([Cys])和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、远程电子转移、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。电子顺磁共振一直是用来表征这些自由基物种的主要工具，但直接观测受到信号自旋轨道展宽的影响，这降低了该方法的有效性。利用硫原子上自由基的性质所产生的S 1s-gt；3p前缘跃迁直接探测了这些自由基物种的电子结构，并研究了氢键和电子离域等因素对这些自由基在不同蛋白质环境中的反应活性的影响。这项工作的一个重要目标是发展S K-EDGE XAS作为一种强大而通用的硫自由基物种探针，以研究广泛的生物体系。