Elucidation of Pathways: Bacterial and Mass Spectrometric Studies

细菌与人体密切相关；有益细菌通过帮助消化、防止感染和刺激免疫系统来支持健康和福祉。细菌产生的物质称为代谢物，是定义细菌与宿主关系的分子信号。为了通过揭示疾病治疗的新方向来潜在地受益于生活质量，我们的方法是彻底研究变异梭杆菌，这是一种通常在动物肠道中发现的细菌，可能导致肠道疾病的发生。 我们的研究项目还专注于与质谱学相关的化学过程，这是一种分子首先被带电，然后在输入能量时被分解成碎片的技术。形成的具体片段是诊断性的，为在各种情况下识别毒品、环境污染物和爆炸物提供了基础，并使人们能够得出具有广泛影响的结论(例如，在体育运动中使用违禁物质)。为了更深入地了解这些重要应用背后的基本原理，我们选择了模拟当前药物和候选药物结构的物质，并且可以在一个以上位置容纳电荷，从而增加了它们以两种或多种不同方式分解的可能性(即碎片路径)。随着我们的解释性发展，质谱学将提供更丰富和更可靠的信息，增加其作为表征药物代谢物的基本工具的价值，并缩短完成未来新药开发这一关键步骤所需的时间。 作为对遗传学研究的补充，我们正在进行的化学研究已经证明了肠道细菌的代谢多样性导致了八种物质的产生，其中一种可能具有意想不到的分子信号功能，与肠道疾病有关。通过确定形成这些代谢物的途径，厌氧细菌中独特的代谢过程可以被评估为选择性代谢抑制剂的靶点，这是一种新的合理设计策略，用于产生新型抗生素的先导化合物，有效地对抗目前抗生素治疗的病原菌。此外，排出的三种细菌代谢物具有重要的实际应用，作为可持续的化学原料使用，例如，在生物医学应用的生物降解聚合物的制造中。 在这项申请中，申请资金是为了进行两项看似不同的研究调查。然而，我们对途径阐明的机械性研究方法的思维过程中的共同点和所研究物质的性质提供了显著的重叠。对于每一条途径，我们设计和合成探针来测试途径假说，使用标有稳定同位素的物质收集证据，并在逻辑上吸收证据，以提供对每条途径的可靠描述。总体而言，我们解决了肠道细菌和人类宿主之间关系的基本问题，这是一个复杂且相对未被探索的领域，位于细菌和人类新陈代谢的交叉点。我们在基础科学方面的研究计划将为解释和应用重要的连续化学过程、实施可持续发酵方法以及潜在的药物研究和发现的新途径提供新的见解。

Bacteria are intimately associated with the human body; beneficial bacteria support health and well-being by aiding digestion, protecting against infection, and stimulating the immune system. Substances produced by bacteria, known as metabolites, act as molecular signals defining the bacterium-host relationship. To potentially benefit the quality of life by revealing new directions for the treatment of disease, our approach is to thoroughly study Fusobacterium varium, a bacterium typically found in the intestines of animals that may contribute to the initiation of bowel disease. Our research program also focuses on chemical processes associated with mass spectrometry, a technique in which molecules are first charged and then broken into pieces upon input of energy. The specific pieces formed are diagnostic, providing a basis for the identification of drugs, environmental contaminants and explosives in various situations and allowing conclusions to be drawn that have broad implications (e.g., the use of banned substances in sports). To develop a deeper understanding of fundamentals behind these important applications, we choose substances that mimic the structures of current drugs and drug candidates, and can accommodate charge in more than one location, increasing their likelihood to break apart in two or more different ways (i.e., fragmentation pathways). With our interpretative developments, mass spectrometry will provide enriched and more reliable information, increasing its value as an essential tool for the characterization of drug metabolites and shortening the time needed to complete this essential step in the development of prospective new drugs. As a complement to genetic studies, our on-going chemical research has demonstrated metabolic diversity in the intestinal bacterium leading to the production of eight substances, of which one may have an unanticipated function as a molecular signal with implications in bowel disease. By identifying the pathways used to form these metabolites, unique metabolic processes in anaerobic bacteria can be evaluated as targets for selective metabolic inhibitors, a novel rational design strategy for the generation of lead compounds for novel antibiotics effective against pathogenic bacteria resistant to current antibiotic treatments. Also, three of the bacterial metabolites excreted have important practical applications as sustainable chemical feed stocks used, for example, in the manufacture of biodegradable polymers with biomedical applications. In this application, funding is requested to pursue two seemingly diverse research investigations. However, commonalities in the thought process of our mechanistic investigative approach to pathway elucidation and the nature of the substances studied provide significant overlap. For each, we design and synthesize probes to test pathway hypotheses, collect evidence using substances labelled with stable isotopes, and logically assimilate the evidence to provide a reliable description of each pathway. Overall, we tackle fundamental questions in the relationship between intestinal bacteria and human hosts, a complex and relatively unexplored area at the intersection of bacterium and human metabolism. Our research program in fundamental science will offer new insights for the interpretation and application of important sequential consecutive chemical processes, the implementation of sustainable fermentation methods, and potentially new avenues of drug research and discovery.