SULFUR SPECIATION IN PLANT LEAVES/LICHENS, AND STUDIES OF METAL-CYS COMPLEXES US

植物叶子/地衣中的硫形态以及金属-CYS 复合物的研究

• 批准号: 7954197
• 负责人: FARIDEH JALILEHVAND
• 金额: $ 0.52万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7954197
• 关键词: Air; Alberta province; Amino Acids; Area; Canada; Chemicals; Chemistry; Complex; Computer Retrieval of Information on Scientific Projects Database; Cysteine; Digestion; Drug Metabolic Detoxication; Electronics; Elements; Environment; Funding; Gases; Grant; Heating; Heavy Metals; Institution; Ions; Lichen - organism; Life; Ligands; Metals; Methods; Monitor; Organism; Physiological; Plant Leaves; Plants; Research; Research Personnel; Resources; Roentgen Rays; Sampling; Sampling Studies; Site; Solutions; Source; Spectrum Analysis; Structure; Sulfhydryl Compounds; Sulfur; Sulfur Metabolism Pathway; United States National Institutes of Health; X-Ray Crystallography; absorption; carboxylate; metal complex; solid state; structural biology; synchrotron radiation

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. Sulfur is an essential element for plants, being converted into cysteine and then to other sulfur metabolites. Current research on sulfur metabolism in plants is severely restricted by the present "wet chemistry" methods for identifying sulfur species, which require digestion/heating/destruction of the sample and only provide rather inaccurate "total organic" vs. "total inorganic" amounts of sulfur. By means of sulfur K-edge X-ray absorption spectroscopy (XAS) we will perform detailed speciation analyses of the major sulfur species present in intact plant leaves to clarify the key steps in the sulfur metabolism. We will also study samples from areas in Alberta, Canada, exposed to well-documented extensive sour gas emissions, to investigate the effects on the sulfur metabolism. Lichens, which only take up sulfur from the air, are great natural monitors for sour gas effects. Cysteine and its derivatives are medically used for heavy metal detoxification. Cysteine, one of 21 amino acids found in living organisms, contains three coordinating sites: the amino, thiol and carboxylate groups. The thiol group can form strong bonds and accumulate ions of soft, heavy metals. Coordination chemical studies have so far been focused on metal complexes in the solid state, mostly by elemental analysis, IR and in a few cases, X-ray crystallography. Little is known about the structure and coordination in solution, near to physiological conditions. We will use metal and sulfur XAS to study the local structure around the metal center, i.e. the metal-ligand bond distances, number and type of coordinating atoms, as well as the electronic environment around the sulfur atom in complexes of heavy metals, e.g. Pb, Cd, Hg and Ag, with cysteine and its derivatives.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 硫是植物的重要元素，被转化为半胱氨酸，然后转化为其他硫代谢物。当前对植物中硫代谢的研究受到当前的“湿化学”方法的严格限制，这些方法需要消化/加热/加热/破坏样品，并且仅提供相当不准确的“总有机物”与“总无机”硫量。通过硫K边缘X射线吸收光谱（XAS），我们将对完整植物叶片中存在的主要硫种类进行详细的物种形成分析，以阐明硫代谢的关键步骤。我们还将研究来自加拿大艾伯塔省的地区的样品，暴露于有据可查的广泛的酸性气体排放中，以研究对硫代谢的影响。地衣只占据空气中的硫，是酸气效应的绝佳天然监测器。半胱氨酸及其衍生物用于重金属排毒。半胱氨酸是生物体中发现的21种氨基酸之一，其中包含三个配位地点：氨基，硫醇和羧酸盐基团。硫醇群可以形成牢固的键并积聚软金属的离子。迄今为止，协调化学研究集中在固态的金属络合物上，主要是通过元素分析，IR和少数情况下的X射线晶体学。关于溶液中的结构和协调知之甚少，接近生理条件。我们将使用金属和硫XAS研究金属中心周围的局部结构，即金属配体键距离，配位原子的数量和类型以及重金属络合物中硫原子周围的电子环境，例如。 PB，CD，HG和AG，具有半胱氨酸及其衍生物。