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维持健康和幸福。细菌产生的被称为代谢物的物质，作为定义细菌-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改善生活质量，我们的方法是彻底研究各种梭杆菌，一种通常在动物肠道中发现的细菌，可能有助于肠道疾病的开始。*我们的研究项目还侧重于与质谱相关的化学过程，这是一种分子首先带电，然后在输入能量时分解成碎片的技术。所形成的具体碎片是诊断性的，为在各种情况下识别药物、环境污染物和爆炸物提供基础，并可得出具有广泛影响的结论（例如，在体育运动中使用禁用物质）。为了更深入地了解这些重要应用背后的基础知识，我们选择了模仿当前药物和候选药物结构的物质，并且可以在多个位置容纳电荷，从而增加它们以两种或更多种不同方式（即破碎途径）分解的可能性。随着我们的解释性发展，质谱分析将提供丰富和更可靠的信息，增加其作为药物代谢物表征的基本工具的价值，缩短完成这一重要步骤所需的时间。*作为遗传学研究的补充，我们正在进行的化学研究已经证明肠道细菌的代谢多样性导致八种物质的产生，其中一种物质可能具有意想不到的功能，作为肠道疾病的分子信号。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作为选择性代谢抑制剂的靶标进行评估，这是一种新的合理设计策略，可以产生针对当前抗生素治疗耐药致病菌的新型抗生素先导化合物。此外，排泄的细菌代谢物中有三种具有重要的实际应用，可作为可持续的化学原料，例如用于制造具有生物医学用途的可生物降解聚合物。*在此申请中，资金被要求进行两个看似不同的研究调查。然而，在我们的途径阐明的机械调查方法的思想过程中的共性和所研究物质的性质提供了显著的重叠。对于每一个，我们设计和合成探针来测试途径假设，使用标记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每个途径的可靠描述。总的来说，我们解决了肠道细菌和人类宿主之间关系的基本问题，这是细菌和人类代谢交叉的一个复杂且相对未开发的领域。我们在基础科学方面的研究项目将为重要连续化学过程的解释和应用、可持续发酵方法的实施以及药物研究和发现的潜在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.