CAREER: Determining the Metabolic Organization and Enzymology of the Fundamentally Important Flavonoid Biosynthetic Pathway

新陈代谢，即在维持生命的细胞内发生的一系列化学反应，通常以线性方式表示，每个反应的输入和输出被认为与支配这些反应的酶的空间排列无关。这项工作的一个主要目标是将新陈代谢的观点从目前的线性二维模型扩展到更全面的三维表示。新陈代谢是一组酶，它们通过相互作用以三维方式组织起来，产生一台可以引导流动并影响整个系统的路径的“机器”。新陈代谢形成的测定提供了关于不同化合物如何在活体中产生的基本信息，并使人们深入了解如何操纵这些系统来改进感兴趣的化合物的产生。本工作以柑橘为材料，研究类黄酮生物合成途径中代谢产物的组织结构，为人类利用类黄酮生物合成途径服务。这项工作的更广泛的影响包括类黄酮研究的内在本质，类黄酮具有重要的健康和营养特性。与学生的额外工作将包括参与研究本身的机会，外展努力将教会学生如何种植自己的食物。这些活动将包括一项有重点的努力，将在科学领域代表性不足的太平洋岛民包括在内。希望这些活动能吸引年轻人的兴趣，使他们接触到目前在科学和农业领域取得成功的导师。该项目的总体研究目标是确定橙子中类黄酮生物合成途径的代谢组织和酶学。中心假设是，橙子中黄酮类最终产物的积累取决于新陈代谢的形成。这项研究的基本原理是，确定橙类黄酮生物合成途径的酶学和代谢组织将确定目标，以改进类黄酮代谢物的含量和质量，应用于有益于人类的应用。这些目标将通过确定参与橙类黄酮生物合成的代谢酶的结构-功能关系，并确定组成金发和橙血品种的类黄酮代谢的酶的组织结构来实现。这项工作是在先前使用拟南芥模型系统的基础上扩展的，使用了在农业上具有重要意义的物种橙子，这使得分析积累早期和晚期类黄酮的物种之间代谢形成的差异。糖基转移酶也将被研究，因为它们有助于产生大多数在体内积累但目前研究不足的类黄酮化合物。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Metabolism, or the set of chemical reactions that occur inside cells that sustain life, is typically represented in a linear fashion, with inputs and outputs of each reaction considered independent of the spatial arrangement of enzymes that govern those reactions. A primary objective of this work is to expand the view of metabolism beyond current linear two-dimensional models to more holistic three-dimensional representations. A metabolon is a group of enzymes that organize in three dimensions by interacting together to generate a “machine” that can direct flow and influence the path through the overall system. Determining metabolon formation provides fundamental information on how different compounds are produced in living organisms and gives insight into how to manipulate these systems to improve the production of compounds of interest. This work focuses on using orange (Citrus sinensis) to determine metabolon organization of the flavonoid biosynthetic pathway, which can be utilized for human benefit. The Broader Impact of this works includes the intrinsic nature of the research on flavonoids, which have important health and nutritional qualities. Additional work with students will include opportunities to become involved in the research itself and outreach efforts will teach students how to grow their own food. The activities will include a focused effort to include Pacific Islanders who are underrepresented in science. It is hoped these activities will capture the interest of young people due to the hands-on components and expose them to mentors who are currently successful in science and agriculture.The overall research objective for this project is to determine the metabolic organization and enzymology of the flavonoid biosynthetic pathway in orange. The central hypothesis is that accumulation of flavonoid end products in orange depends upon formation of a metabolon. The rationale for the proposed research is that a determination of the enzymology and metabolic organization of the orange flavonoid biosynthetic pathway will identify targets for improving the content and quality of flavonoid metabolites for applications beneficial to humanity. These objectives will be achieved by identifying structure-function relationships of metabolon enzymes involved in biosynthesis of orange flavonoids, and determine the organization of enzymes comprising flavonoid metabolons of blonde and blood varieties of orange. The work expands from prior use of the model system Arabidopsis thaliana by employing the fundamentally and agriculturally important species orange, which allows analysis of differences in metabolon formation between species that accumulate early and late flavonoids. Glycosyltransferase enzymes will also be studied as they contribute to the production of the majority of flavonoid compounds which accumulate in vivo but are currently understudied.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.