SPECTROSCOPIC SPECIATION OF SULFUR IN WHOLE CELLS

描述：（申请人的摘要）生物化学围绕 碳的化学性质，但许多其他元素也起着重要作用。 硫 这样一种元素，在结构，催化和新陈代谢中发挥作用， 有机体 特别是在人类中，同型半胱氨酸血症，连同低 腺苷甲硫氨酸水平，已牵连在冠状动脉疾病 和动脉粥样硬化性疾病。 我们的目标是开发硫K边X射线 吸收近边光谱，使其可用于监测和 提高我们对生命系统中硫代谢的理解。 有 目前还没有生物系统中硫的有效光谱探针。 X射线吸收光谱将检测所有化学形式的硫在一个 样品，在固体中，在水溶液中或在任何其他形式，和不同的 硫的形态显示出明显不同的光谱。 无预处理 需要，并且该技术至少是潜在的非破坏性的。 的 我们在此提出的工作的最终潜力是提供一种体内 代谢状态的探针。 为此，我们建议这项初步研究的具体目标如下： 1. 生成一系列生物样品的硫光谱库 在一系列生理学相关条件下的显著化合物。 2. 开发统计上严格的曲线拟合程序，用于评估 复杂的混合物，并定量评估粒度和 浓度效应。 3. 评估辐射的潜在问题 损坏，包括样品冷冻保护的要求。 4. 通过对简单生物系统的初步研究， 硫在新陈代谢中起着重要作用。 5. 应用开发的 技术到更具挑战性的真核系统。 后一个目标可能不会 在补助金发放的最初阶段实现。

DESCRIPTION: (applicant's abstract) Biochemistry revolves around the chemistry of carbon, but many other elements play vital roles. Sulfur is such an element, with roles in structure, catalysis and metabolism in all organisms. Specifically in humans, homocysteinemia, together with low S-adenosyl methionine levels, has been implicated in coronary artery disease and in atherosclerotic disease. Our goal is to develop sulfur K-edge X-ray absorption near-edge spectroscopy so that it can be used to monitor and to improve our understanding of sulfur metabolism in living systems. There are currently no effective spectroscopic probes of sulfur in biological systems. X-ray absorption spectroscopy will detect all chemical forms of sulfur in a sample, in solid, in aqueous solution or in any other form, and different forms of sulfur display strikingly different spectra. No pre-treatment is needed and the technique is at least potentially non-destructive. The ultimate potential of the work we propose herein is to provide an in vivo probe of metabolic status. To this end, we propose the following specific aims for this initial study: 1. Generate a library of sulfur spectra of a range of biologically significant compounds under a range of physiologically relevant conditions. 2. Develop statistically rigorous curve-fitting routines for evaluation of complex mixtures, and quantitatively evaluate particle size and concentration effects. 3. Evaluate the potential problems from radiation damage, including the requirement for cryo-protection of the sample. 4. Validate our approach by initial studies of simple biological systems where sulfur plays very major roles in metabolism. 5. Apply the developed techniques to more challenging eukaryotic systems. This latter aim may not be achieved in the initial period of the grant.