Natural product discovery and biosynthetic pathway elucidation from the human pathogen Legionella

人类病原体军团菌的天然产物发现和生物合成途径阐明

• 批准号: 10751257
• 负责人: Zheng Cui
• 金额: $ 7.86万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10751257
• 关键词: Acute; Affect; Anabolism; Bioinformatics; Biological; Biological Assay; Chemical Structure; Cytotoxic agent; Emerging Communicable Diseases; Enzymes; Fatality rate; Fever; Gene Cluster; Gene Expression; Gene Targeting; Genes; Health care facility; Homologous Gene; Host Defense; Impairment; Infection; Investigation; Legionella; Legionella pneumophila; Legionellosis; Legionnaires' Disease; Mediating; Medicine; Natural Products; Nature; Neighborhoods; Nitrites; Nitroreductases; Organism; Outcome; Pathway interactions; Play; Prodrugs; Proteins; Reaction; Research; Resistance; Role; Source; Substrate Specificity; Testing; Time; Virulence; Virulent; Work; bioactive natural products; biomarker identification; combat; design; drug candidate; fighting; human pathogen; inhibitor; knockout gene; metabolomics; metalloenzyme; microbial; mutant; novel; pathogenic microbe; pharmacophore; secondary metabolite; small molecule

Project Summary: Natural products play essential biological roles in producing organisms and have been a historically important source of medicines. Microbial natural products research has focused largely on environmental organisms; natural products, especially the potential small molecule virulent factor produced by pathogenic microbes, are much less understood. Legionella infection causes Legionellosis, which can be present in its non-pneumonic form as Pontiac fever or acute pneumonic form as Legionnaires’ disease. The fatality rate of legionnaires disease is about 10% due to complications and about 25% for those infected in the healthcare facility. While how the protein effectors of Legionella affect the host have been intensively studied, identifying the secondary metabolites Legionella produce and the roles these natural products play in Legionella infection are understudied. The proposed work will identify and characterize the potential bioactive nature products from the human pathogen Legionella. Using a gene-targeting approach to identify a potential novel metalloenzyme that catalyzes unusual oxidative rearrangement to generate the N-nitroso product, one homolog conserved in over 170 Legionella pneumophila subspecies and another homolog conserved in Legionella drozanskii was discovered. Activity assay shows this homolog catalyzes similar reactions but utilizes different substrates. Bioinformatic analysis of the gene neighborhood identifies the biosynthetic gene cluster (BGC) encodes resistance enzyme and a prodrug activating enzyme, possibly indicating the biosynthesis of potential bioactive metabolites. Aim 1 will identify the natural product and bioactivity from the biosynthetic gene cluster from Legionella to uncover the potential virulent factor. Aim 2 will initiate the characterization and mechanistic study of two enzymes in the BGC involving the biosynthesis of the potential pharmacophore to facilitate the understanding and pave the way for the inhibitor design of this new class of pharmacophore-producing enzyme pair. Successful completion of these aims will identify the chemical structure of the potential bioactive natural products from the human pathogen Legionella. In addition, two key enzymes involving the potential pharmacophore biosynthesis will also be characterized. Identification of those natural products and their biosynthesis will possibly reveal new virulence pathways that can be targeted to combat Legionella infection. Ultimately, the overall workflow will be generalized to investigate other novel natural products or potential virulent factors from the human pathogen Legionella to fight the emerging infectious disease by expanding the pool of 1) new classes of cytotoxic drug candidates/virulent factors and 2) new inhibition targets from the biosynthetic pathway.

项目摘要： 天然产品在生产生物中起着重要的生物学作用，并且一直是历史上重要的 药物来源。微生物天然产品研究主要集中在环境生物上。 天然产物，尤其是致病微生物产生的潜在的小分子毒物，是 不了解。军团菌感染会导致军团病，可以存在于其非pneumonic中 形式为庞蒂亚克热或急性肺炎形式作为军团疾病。军团疾病的死亡率 由于并发症，大约10％的人，在医疗机构中被感染的人约为25％。而如何 军团菌的蛋白质作用影响宿主已经进行了强烈的研究，识别次要 这些天然产物在军团菌感染中的代谢产物和这些天然产物的作用被了解。 拟议的工作将确定并表征人类潜在的生物活性自然产品 病原体军团菌。使用靶向基因的方法来识别催化潜在的新型金属酶 不寻常的氧化物重排以生成N-硝基产品，一种配置的同源物 170 Legionella pneumophila亚种和在军团菌中保存的另一个同源物是 发现。活动评估表明，这种同源物催化相似的反应，但利用了不同的底物。 基因邻域的生物信息学分析识别生物合成基因簇（BGC）编码 抗性酶和前药激活酶，可能表明潜在生物活性的生物合成 代谢物。 AIM 1将从生物合成基因簇从军团菌到 发现潜在的有毒因素。 AIM 2将启动两种酶的表征和机械研究 在涉及潜在药效团的生物合成的BGC中，以促进理解和铺路 这类新型药效生产酶对的抑制剂设计的方式。成功的 这些目标的完成将确定潜在的生物活性天然产物的化学结构 人病原体军团菌。此外，两个关键酶涉及潜在的药效团生物合成 也将被描述。这些天然产品及其生物合成的识别可能会揭示新的 可以针对对抗军团菌感染的病毒途径。最终，整体工作流将是 普遍研究其他新型天然产物或人类潜在的毒物 病原体军团菌通过扩展1）新类细胞毒性来对抗新兴疾病 候选药物/有毒因素和2）生物合成途径的新抑制靶标。