Synchrotron studies of selenium environmental chemistry

硒环境化学的同步加速器研究

• 批准号: RGPIN-2016-05810
• 负责人: Pickering, Ingrid
• 金额: $ 4.44万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=662148
• 关键词: Synchrotron; studies; selenium; environmental; chemistry

Selenium in the environment. As a micronutrient element required for all kingdoms of life, selenium (Se) is one of the least abundant micronutrients in the earth's crust. World Se distribution is highly variable; while Canada's prairie soils are among the richest yielding higher Se crops, globally soils are more likely to provide inadequate Se. Moreover, Se has a smaller difference between sufficient and excess dietary amounts than perhaps any other element. There is growing concern over slightly elevated Se in aqueous environments in several areas of Canada due to mining or other anthropogenic activities, since bioaccumulation of Se can cause problems for top predators. This delicate balance between insufficient and excess is just one challenge of Se.****Selenium in organisms. The twenty-first amino acid selenocysteine occurs in active sites of key enzymes such as glutathione peroxidase. In addition Se has enigmatic biological interactions with toxic elements including mercury, arsenic and cadmium. While some Se chemical forms can protect against such elements, in other scenarios Se can increase toxicity. Although the former is at least partly understood, the latter mechanisms remain a mystery. ******Objectives. The program seeks a holistic view of the roles and interactions of Se at the molecular level both in the environment and in impacting human health. Knowing the chemical form of Se is key to understanding its function and impact, whether detrimental, benign or beneficial. ******Scientific approach. Building upon career contributions, the program will use and develop synchrotron techniques, sharing refinements with the research community especially at the Canadian Light Source BioXAS beamlines where the applicant is scientific co-lead. X-ray absorption spectroscopy provides speciation information while X-ray fluorescence imaging yields microscopic elemental distributions in biological samples with little pretreatment. Studies will include structural characterization of purified biomolecules to determine Se functions. Other projects will address Se distribution, chemical forms and interactions with other elements in plants and animal models in order to understand underlying mechanisms.******Training. Highly qualified personnel trained through cross-disciplinary projects to use and develop specialized synchrotron tools will be more generally adept at adapting technologies to solve problems, positioning them for high profile careers.******Strategic relevance. High soil Se in Canada's prairies leads to crops rich in Se, potentially increasing their nutritional value. Conversely, slightly elevated Se in mining runoff can be environmentally problematic. Both positive and negative faces of Se have significant economic consequences. This work advances understanding of Se's contrasting roles in living organisms, essential in assessing both positive and negative aspects of Se in Canada. **

环境中的硒作为所有生命王国所需的微量营养元素，硒（Se）是地壳中含量最少的微量营养元素之一。世界硒的分布是高度可变的，而加拿大的草原土壤是最富有的高产硒作物，全球土壤更有可能提供不足的硒。此外，硒在充足和过量膳食量之间的差异可能比任何其他元素都小。由于采矿或其他人为活动，加拿大几个地区的水环境中硒含量略有升高，这一点越来越引起人们的关注，因为硒的生物积累会给顶级捕食者带来问题。这种不足和过剩之间的微妙平衡只是Se. * 的挑战之一。有机体中的硒第二十一个氨基酸硒代半胱氨酸出现在关键酶如谷胱甘肽过氧化物酶的活性位点。此外，硒与汞、砷和镉等有毒元素具有神秘的生物相互作用。虽然一些硒的化学形式可以保护这些元素，但在其他情况下，硒可以增加毒性。虽然前者至少部分地被理解，但后者的机制仍然是一个谜。* 目标。该计划旨在从分子水平上全面了解硒在环境和影响人类健康方面的作用和相互作用。了解硒的化学形式是了解其功能和影响的关键，无论是有害的，良性的还是有益的。* 科学方法。在职业贡献的基础上，该计划将使用和开发同步加速器技术，与研究界分享改进，特别是在加拿大光源BioXAS光束线，申请人是科学共同领导。X射线吸收光谱法提供了物种信息，而X射线荧光成像产生的生物样品中的微观元素分布，几乎没有预处理。研究将包括纯化的生物分子的结构表征，以确定硒功能。其他项目将涉及硒的分布，化学形式以及与植物和动物模型中其他元素的相互作用，以了解潜在的机制。训练通过跨学科项目培训的高素质人员使用和开发专业的同步加速器工具，将更普遍地善于适应技术来解决问题，使他们能够从事高调的职业。战略相关性。加拿大大草原的土壤硒含量高，导致农作物富含硒，可能增加其营养价值。相反，采矿径流中硒含量稍高可能会造成环境问题。硒的正面和反面都有显著的经济后果。这项工作促进了对Se在生物体中不同作用的了解，这对于评估加拿大Se的积极和消极方面至关重要。**