Organometallic Sensors for Cellular Small Molecule Detection

7.项目总结/摘要 非生物过渡金属催化剂在生物系统中的应用已经经历了适应性调整， 近年来，从人工金属酶到分子酶， 用于检测一氧化碳等挑战性分析物的探针。PI对以下方面有长期利益 发现、开发和理解用于检测具有挑战性的生物相关性的策略 分子通过过渡金属的独特反应性。最近，米歇尔集团报告说， 乙烯探针（BEPs）作为第一个荧光活性传感器（ABS），用于检测 生物系统中的乙烯。这些ABS采用公知的钌烯烃复分解催化剂， 已知容易与乙烯反应。 虽然乙烯长期以来一直被认为是一种重要的植物激素，但它也被证明是 在哺乳动物中产生的氧化应激是许多疾病的标志。特别是 乙烯由脂质过氧化物和/或其形成过程中的中间体的自由基断裂产生。 脂质过氧化物的形成是活性氧的结果，活性氧被认为是发挥作用的重要因素。 压力或信号作用，包括癌症，心血管疾病， 神经退行性疾病等。虽然有一些复杂的光谱方法 为了灵敏地测量呼出气中的生物标志物乙烯，这些方法是必要的。 受空间分辨率和样本复杂度的限制。自从报告了我们最初的ABS方法以来，我们的团队 进行了系统的配体调节研究，以提高探针的响应时间和灵敏度。 通过这项工作，检测限提高了近两个数量级。尽管有这些 尽管取得了一些进展，但在内源性乙烯检测的广泛应用中仍存在重要问题 涉及进一步提高灵敏度同时在生物系统中保持稳健稳定性的修饰。 开发这项技术的下一阶段将建立在机械洞察力和最新进展的基础上 催化烯烃复分解。这将通过跨学科的综合方法来实现， 分析和生物物理表征以及亚细胞定位研究。预计该 拟议的研究将导致高度敏感的乙烯ABS定位于亚细胞位置， 预期发现乙烯的浓度最高。我们希望进一步探索新的 乙烯检测策略超出了通常用于乙烯的剂量测定响应， 其他小分子分析物。正如过去10-15年的情况一样，我们设想， 在细胞环境中运行的过渡金属催化剂的持续增长， 否则无法实现的功能。拟议方案的研究和概念将 继续为这一领域做出重大贡献。 1

7. Project Summary/Abstract The adaptation of abiotic transition metal catalysts for applications in biological systems has undergone remarkable growth in recent years with examples ranging from artificial metalloenzymes to molecular probes for detection of challenging analytes such as carbon monoxide. The PI has a standing interest in discovery, development, and understanding of strategies for detecting challenging biologically relevant molecules via the unique reactivity of transition metals. Most recently, the Michel group reported BODIPY Ethylene Probes (BEPs) as the first profluorescent Activity Based Sensors (ABS) for the detection of ethylene in biological systems. These ABS adapted well-known ruthenium olefin metathesis catalyst, which are known to readily react with ethylene. While ethylene has long been known as an important plant hormone it has also been demonstrated to be produced in mammals as a result of oxidative stress that is hallmark to numerous diseases. In particular ethylene arises from the radical fragmentation of lipid peroxides and/or intermediates in their formation. The formation of lipid peroxides is a result of reactive oxygen species, which are implicated as playing stress or signaling roles in numerous diseases including cancer, cardiovascular disease, and neurodegenerative diseases amongst others. While there are some sophisticated spectroscopic methods for sensitively measuring the biomarker ethylene in exhaled breath, these approaches are necessarily limited in spatial resolution and complexity of sample. Since reporting our initial ABS approach, our group has conducted systematic ligand modulation studies to improve probe response time and sensitivity. Through this work the limit-of-detection was improved nearly two orders of magnitude. Despite these advancements, important questions remain for broad applications in the detection of endogenous ethylene related to modifications that further improve sensitivity while retaining robust stability in biological systems. The next stage of developing this technology will build on mechanistic insight and recent advancements in catalytic olefin metathesis. This will be accomplished through an interdisciplinary approach of synthesis, analytical and photophysical characterization, and subcellular localization studies. It is anticipated that the proposed research will result in highly sensitive ethylene ABS localized to subcellular locations where ethylene is expected to be found in the highest concentrations. Further we expect to explore novel strategies for ethylene detection beyond the dosimetric responses generally employed for ethylene and other small molecule analytes. As has been the case over the past 10-15 years, we envision that there will be continued growth of transition metal catalysts operating in cellular environments to perform critical functions that would otherwise not be possible. The research and concepts of the proposed program will continue to significantly contribute to this field. 1