SPECTROSCOPIC SPECIATION OF SULFUR IN WHOLE CELLS

描述：(申请者摘要)生物化学围绕 碳的化学，但许多其他元素起着至关重要的作用。硫磺是 这是一种在结构、催化和新陈代谢中起作用的元件 有机体。特别是在人类中，同型半胱氨酸血症和低 S-腺苷蛋氨酸水平，已被认为与冠心病有关 在动脉粥样硬化性疾病中。我们的目标是开发硫磺K-Edge X射线 吸收近边光谱学，因此它可以用于监测和 提高我们对生命系统中硫代谢的理解。确实有 目前还没有有效的硫在生物体系中的光谱探针。 X射线吸收光谱分析将检测出硫的所有化学形态 样品，固体、水溶液或任何其他形式，不同 硫磺的形态表现出明显不同的光谱。没有任何前处理是 而且这种技术至少是潜在的非破坏性的。这个 我们在此提出的工作的最终潜力是在体内提供一种 新陈代谢状态的探查。 为此，我们为这项初步研究提出以下具体目标： 1.生成一系列生物硫光谱的库 在一系列生理相关条件下的重要化合物。 2.开发统计严格的曲线拟合例程，用于评估 复杂混合物，并定量评估颗粒大小和 集中效应。3.评估辐射带来的潜在问题 损坏，包括对样品进行冷冻保护的要求。4. 通过对简单生物系统的初步研究来验证我们的方法 硫在新陈代谢中起着非常重要的作用。5.应用已开发的 更具挑战性的真核系统的技术。后一个目标可能不会 将在赠款的初期实现这一目标。

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.