Structure-function studies on glutamate-1-semialdehyde aminomutase (GSAM)- A key enzyme in chlorophyll biosynthesis

叶绿素生物合成关键酶谷氨酸-1-半醛氨基变位酶（GSAM）的结构功能研究

• 批准号: 342077-2012
• 负责人: Stetefeld, Jörg
• 金额: $ 2.48万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=527571
• 关键词: Structure; function; studies; glutamate; semialdehyde

Cofactors like heme, chlorophyll, coenzyme F430, and carotinoids are constructed from eight molecules of 5-aminolevulinate, which forms the building block for all tetrapyrrols. In plants and bacteria, this compound is synthesized by the negative cooperative key enzyme glutamate-1-semialdehyde aminomutase (GSAM). The primary goal of the proposed research program is to understand in detail the structure-function relationship and catalytic mechanism of GSAM. The purpose is to obtain mechanistic and chemical information about this enzyme with the goal (i) to investigate the evolutionary relationship between the C5 -and the Shemin-pathways, (ii) to shed light into the inter-subunit signaling during catalytic turnover and (iii) to design and analyze specific inhibitors against GSAM. Because no counterpart of this enzyme exists in animals, it is a promising target for safe, selective herbicides and the rational design of such compounds. In the Stetefeld laboratory, an integrated approach will be performed. These studies involve a combination of structural (X-ray crystallography and solution NMR), spectroscopical (UV-VIS and Foerster Resonance Electron Transfer) techniques together with functional assays and kinetic studies. These experiments will be complemented by Molecular Dynamic simulations. Not only will the research enhance our knowledge of the allosteric communication during enzyme catalysis, but insights will be gained into structure-based drug design of highly selective herbicides. Understanding the complex mechanisms of enzyme promiscuity during evolutionary selection will provide further information about protein chemistry with great biotechnological relevance. The results will contribute to basic knowledge under the global perspective of designing specific and targeted inhibitors.

血红素、叶绿素、辅酶 F430 和类胡萝卜素等辅助因子由 8 个 5-氨基乙酰丙酸盐分子构成，它构成了所有四吡咯的基础材料。在植物和细菌中，该化合物由负协同关键酶谷氨酸-1-半醛氨基变位酶 (GSAM) 合成。该研究计划的主要目标是详细了解 GSAM 的结构-功能关系和催化机制。目的是获得有关该酶的机制和化学信息，目标是 (i) 研究 C5 和 Shemin 途径之间的进化关系，(ii) 揭示催化周转过程中的亚基间信号传导，以及（ iii) 设计和分析 GSAM 的特异性抑制剂。由于动物体内不存在这种酶的对应物，因此它是安全、选择性除草剂和此类化合物的合理设计的有希望的目标。 Stetefeld 实验室将采用综合方法。这些研究涉及结构（X 射线晶体学和溶液核磁共振）、光谱（UV-VIS 和福斯特共振电子转移）技术以及功能测定和动力学研究的组合。这些实验将得到分子动力学模拟的补充。该研究不仅将增强我们对酶催化过程中变构通讯的了解，还将深入了解基于结构的高选择性除草剂药物设计。了解进化选择过程中酶混杂的复杂机制将提供有关具有重大生物技术相关性的蛋白质化学的进一步信息。研究结果将有助于在全球视角下设计特异性和靶向抑制剂的基础知识。