Biogeochemistry of Iron, Iodine and Boron in Marine Plant-like Linages: Synchrotron Radiation Methods for Visualizing Chemical State, Localization and Potential Interactions

获得这一奖项的是美国国家科学基金会化学部生命过程化学项目，支持卡尔·J·卡拉诺和弗里斯约夫·C·库珀关于海藻如何吸收和储存重要的微量元素(铁、硼和碘)，以及这些元素如何相互作用从而影响植物生物学的研究。海藻是一种重要的资源，在食品、化妆品和化肥工业中有着广泛的用途。作为生物燃料的来源，它们也吸引了越来越多的关注，这些生物燃料不会与陆地植物竞争食物生产。该项目利用先进的高分辨率同步辐射方法来确定铁、碘和硼在两种重要海藻中的准确位置和化学状态，并利用这些信息来帮助确定它们之间相互作用的生物学重要性。这项工作还为研究生和本科生提供了广泛的重要技术培训。此外，由于圣地亚哥州立大学拥有较高的少数民族人口(在美国少数民族学士学位授权者中排名第十)，因此这一研究项目有望对少数民族的科学培训产生积极影响。外展活动也在进行中。虽然在细胞质中，许多金属蛋白是以复杂的混合物形式存在的，但在没有事先具有潜在破坏性的情况下，很难进行简单的分析，当然也没有潜在的破坏性、分离和纯化。许多其他金属蛋白储存、隔离或定位在细胞/细胞器内的离散位置，也很难分离和研究。随着同步辐射(SR)的分辨率和通量密度的提高，有可能精确定位这样的系统，并直接在原位分析和表征它们，而不需要分离或纯化。因此，这项研究的一个目标是，鉴于第三代同步加速器能力的不断增强，在显著进步(在亮度和分辨率方面)的情况下，将应用于生物样品的痕量元素的化学状态、定位和潜在相互作用可视化的SR方法的限制是什么。该项目利用先进的高分辨率(微米到亚微米)SR方法，即微探针、3D断层成像、IR/拉曼、XANES和EXAFS，来确定两种模式海洋大型藻类(Etocarpus silulsis，Macrocystis pyrifera)中铁、碘和硼的精确位置和化学状态。研究人员使用这些信息来帮助确定元素之间相互作用的生物学重要性。海藻是一种重要的资源，在食品、化妆品和化肥工业中有着广泛的用途。作为生物燃料的来源，它们也吸引了越来越多的关注，这些生物燃料不会与陆地植物竞争食物生产。

With this award the Chemistry of Life Processes Program of the Chemistry Division of NSF are supporting Carl J. Carrano and Frithjof C. Kupper's study of how important trace elements (iron, boron and iodine) are taken up and stored in seaweeds, and how these elements interact with each other so as to affect the plant biology. Seaweeds represent an important resource with a wide range of uses in the food, cosmetic, and fertilizer industries. They are also attracting increasing attention as a source for biofuels that do not compete with terrestrial plants for food production. The project utilizes advanced high resolution synchrotron radiation methods to define the precise locations and chemical states of iron, iodine and boron in two important seaweeds and uses this information to assist in determining the biological importance of interactions between them. This work also provide training for graduate and undergraduate students in a wide range of important techniques. In addition, since San Diego State University has a high minority population (10th largest grantor of minority bachelor's degrees in the USA), this research project is thus expected to favorably impact minority training in the sciences. Outreach activities are also in progress.While in the cytoplasm many metalloproteins are present as a complicated mixture not easily amenable to simple analysis without prior potentially destructive, and certainly disruptive, isolation and purification. Many other metalloproteins are stored, sequestered or localized in discrete locations within the cell/organelles and are also difficult to isolate and study. As the resolution and flux density of synchrotron radiation (SR) increases, it may be possible to pinpoint such systems and analyze and characterize them directly in situ without need for isolation or purification. Thus, one goal of this research is to see what the limits are for SR methods for visualizing the chemical state, localization and potential interactions of trace elements as applied to biological samples given the increasing capabilities of 3rd generation synchrotrons where significant progress (both in terms of brilliance and resolution) has been evident. The project is using utilizing advanced high resolution (micron to submicron) SR methods, i.e. microprobe, 3D tomography, IR/Raman, XANES and EXAFS to define the precise locations and chemical states of iron, iodine and boron in two model marine macroalgae (Ectocarpus siliculosis, Macrocystis pyrifera). The investigators use this information to assist in determining the biological importance of interactions between the elements. Seaweeds represent an important resource with a wide range of uses in the food, cosmetic, and fertilizer industries. They are also attracting increasing attention as a source for biofuels that do not compete with terrestrial plants for food production.