Determination of the Biological Roles and Chemical Mechanisms of the Glutamate Ra

谷氨酸 Ra 的生物学作用和化学机制的测定

• 批准号: 7740323
• 负责人: Michael Ashley Spies
• 金额: $ 19.81万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-06 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7740323
• 关键词: Address; Affinity; Anabolism; Anthrax disease; Antibiotics; Bacillus anthracis; Bacteria; Binding; Biochemistry; Biological; Cell Wall; Chemicals; D Glutamate; Development; Drug Delivery Systems; Enzymes; Future; Generations; Glutamate racemase; Glutamates; Goals; Grant; In Vitro; Infectious Agent; Knowledge; Mammals; Methodology; Modeling; Outcome; Pathogenesis; Peptidoglycan; Pharmaceutical Preparations; Pharmacologic Substance; Property; Reaction; Research; Role; Screening procedure; Source; Structure; Validation; Work; analog; antimicrobial; antimicrobial drug; base; computational chemistry; design; enzyme activity; enzyme substrate complex; in vivo; inhibitor/antagonist; pathogen; pathogenic bacteria; public health relevance; racemization; small molecule; weapons

DESCRIPTION (provided by applicant): Studies proposed in this R21 application address the urgent need to develop new classes of antibiotics against emerging infectious agents, as well as pathogenic bacteria with the potential to be used as bio-weapons. The long-term goal of the work proposed in this application is to develop a new class of inhibitors against glutamate racemases, which catalyze the stereo-inversion of L- to D-glutamate, an important metabolite for cell wall biosynthesis. Glutamate racemases are essential in several bacteria, but not found in mammals, and are thus predicted to be excellent antibiotic targets. Notably, at least three pharmaceutical companies are currently developing glutamate racemase inhibitors as potential antimicrobial drugs, thereby supporting the potential importance of the glutamate racemases as antimicrobial targets. However, our strategy for inhibitor design is entirely different than these companies, and is based on the transition state structure of glutamate racemase, which we predict will bind to the enzyme with higher affinity than do drugs based on the ground state enzyme-substrate complexes. In this R21 application, we propose exploratory studies towards the goals of (i) characterizing the importance and properties of the two Bacillus anthracis glutamate racemases, RacE1 and RacE2, in vitro and in vivo, and, (ii) generating models of the transition state structures of the reactions catalyzed by both enzymes. This highly interdisciplinary application consolidates considerable expertise in bioorganic and computational chemistry, biochemistry, and bacterial pathogenesis. The Specific Aims are: Specific Aim 1. To characterize the importance and roles of racE1 and racE2. Specific Aim 2. To characterize the transition states of RacE1- and RacE2-catalyzed racemization. The anticipated outcomes of these specific aims will be validation of glutamate racemase as a drug-target in B. anthracis, and the generation of transition state models for both RacE1 and RacE2. From these models, we will identify small molecule transition state analogs that will be screened for inhibitory activities against RacE1 and/or RacE2 enzyme activities. The results from these studies will provide the experimental and conceptual framework for future work to optimize small molecule "leads" into ultra-specific, reaction-based inhibitors with antimicrobial activity. PUBLIC HEALTH RELEVANCE: This application addressed an existing and urgent need to develop new classes of antibiotics against emerging infectious agents, as well as those agents that may potentially be used as bio-weapons. Completion of these studies will result in a new class of inhibitors with potential antimicrobial activity against Bacillus anthracis, which causes anthrax. The methodologies developed by work supported by this grant will also be potentially applicable to the development of antibiotics against other biomedically important pathogenic bacteria.

描述（由申请人提供）：在本R21应用程序中提出的研究涉及开发针对新兴感染剂的新类别的抗生素类别的需求，以及有可能用作生物武器的致病细菌。本应用中提出的工作的长期目标是开发一类针对谷氨酸种族酶的新型抑制剂，该抑制剂催化了L-至D-谷氨酸的立体声，这是细胞壁生物合成的重要代谢物。在几种细菌中，谷氨酸种族酶是必不可少的，但在哺乳动物中未发现，因此被预测为极好的抗生素靶标。值得注意的是，目前至少有三家制药公司正在开发谷氨酸种族酶抑制剂作为潜在的抗菌药物，从而支持谷氨酸种族酶作为抗菌靶标的潜在重要性。但是，我们的抑制剂设计策略与这些公司完全不同，并且基于谷氨酸种族酶的过渡状态结构，我们预测，该结构将与基于基态酶 - 含量复合物的药物更高的亲和力结合。在此R21应用中，我们提出了探索性研究，以（i）表征两种蒽N芽孢杆菌谷氨酸芽孢杆菌种族的重要性和特性，即Race1和Race2，体外和体内，以及（II）产生两种反应的过渡状态结构的模型。这种高度跨学科的应用巩固了在生物有机和计算化学，生物化学和细菌发病机理方面的大量专业知识。具体目的是：特定目的1。表征Race1和Race2的重要性和角色。具体目标2。要表征Race1和Race2催化的种族化的过渡状态。 这些特定目标的预期结果将是将谷氨酸种族酶作为炭疽芽孢杆菌的药物靶向验证，以及Race1和Race2的过渡状态模型的产生。从这些模型中，我们将确定小分子过渡状态类似物，这些类似物将筛选针对Race1和/或Race2酶活性的抑制作用。这些研究的结果将为将来的工作提供实验和概念框架，以优化小分子“铅”成具有抗菌活性的超特异性，基于反应的抑制剂。公共卫生相关性：该应用程序解决了现有且迫切的需求，以开发针对新兴的传染性药物以及可能被用作生物武器的那些代理商。这些研究的完成将导致一类新的抑制剂对炭疽芽孢杆菌的潜在抗菌活性，这会导致炭疽。由该赠款支持的工作开发的方法也可能适用于针对其他生物医学上重要的致病细菌的抗生素开发。