Developing fluorescent probes for the endogenous gaseous transmitters NO and H2S

项目摘要/摘要 这位候选人在加州大学伯克利分校获得博士学位，由肯尼斯·雷蒙德和 罗伯特·伯格曼在那里他研究了主客体化学、分子识别和水溶性催化 超分子络合物。他目前是麻省理工学院斯蒂芬·利帕德实验室的NIH博士后研究员 致力于开发一氧化氮的荧光探针。该候选人的研究兴趣涉及以下领域 分子识别，特别关注微观过程如何导致个体识别 原子、官能团和分子。应聘者将利用他在机械学研究和 作为一名首席研究员，他从事分子识别方面的研究兴趣。他的独立研究将 专注于开发用于检测和成像生物学小分子的新工具。 一氧化氮(NO)和硫化氢(H2S)现在被认为是具有重要生物意义的气体 发射机。一氧化氮和硫化氢都是由内源性产生的，并受到身体的精细调节。一氧化氮是 在低细胞浓度下有利于血管扩张和免疫活性，但过度生产会导致 与癌症发生和几种退行性疾病有关的反应性一氧化氮物种的增殖 神经疾病，包括阿尔茨海默氏症(AD)、帕金森氏症和亨廷顿病，以及多发性 硬化症。同样，硫化氢也与阿尔茨海默病、唐氏综合症和其他形式的金属缺乏症有关。硫化氢 也在炎症和血压调节中发挥积极作用。尽管公认的重要性 在这两种气体传递器中，目前在活细胞中检测的方法都是有限的。 博士后阶段的拟议研究将集中在开发新的非选择性 解决目前检测不到的局限性的荧光探针。过渡金属基无键合位 将用于开发可可逆结合NO的探测器和在近红外光谱中发射的探测器。建议数 荧光探针家族将使用顺磁性(S=1/2)金属作为荧光的双重角色 猝灭剂，无结合部位。NO的配位作用将形成一个抗磁性(S=0)的络合物，并使 悬挂式荧光团的荧光。这类络合物对增溶的吸附或共价吸附 单壁碳纳米管(SWNTs)将用于开发在近红外光谱中发射的非选择性探针。 拟议研究的独立研究阶段将调查硫化氢选择性的设计。 用于内源产生的硫化氢成像的荧光探针。目前，这样的硫化氢检测方法有 缺乏，而且大多数测量依赖于大块组织测量。新型硫化氢选择性荧光探针 用于活细胞将为研究硫化氢的生物功能提供急需的工具。独一无二的 在设计硫化氢选择性荧光探针时，将充分利用硫化氢的物理性质。荧光团 将用特殊设计的保护基团进行衍生化，这些基团只能被硫化氢去除。移除 荧光团保护基团将恢复荧光，从而形成一个打开的硫化氢探针。

Project Summary/Abstract The candidate received his Ph.D. from the UC Berkeley, under the joint direction of Kenneth Raymond and Robert Bergman where he studied host-guest chemistry, molecular recognition, and catalysis in water-soluble supramolecular complexes. He is currently an NIH postdoctoral fellow in Stephen Lippard's laboratory at MIT working on developing fluorescent probes for nitric oxide. The candidate's research interests span the field of molecular recognition with a specific focus on how microscopic processes lead to the recognition of individual atoms, functional groups and molecules. The candidate will use his background in mechanistic studies and molecular recognition to pursue his research interests as a principle investigator. His independent research will focus on the development of new tools for the detection and imaging of small molecules in biology. Nitric oxide (NO) and hydrogen sulfide (H2S) are now accepted as biologically important gaseous transmitters. Both NO and H2S are produced endogenously and are finely regulated by the body. Nitric oxide is beneficial for vasodilation and immune activity at low cellular concentrations but overproduction can lead to the proliferation of reactive NO species that have been implicated in carcinogenesis and several degenerative neurological disorders, including Alzheimer's (AD), Parkinson's, and Huntington's disease, as well as multiple sclerosis. Similarly, H2S has been implicated in AD, Downs syndrome and other forms of metal deficiency. H2S also plays an active role in inflammation and in blood pressure regulation. Despite the recognized importance of both of these gaseous transmitters, the current methods for detection in live cells are limited. The postdoctoral phase of the proposed research will focus on the development of new NO-selective fluorescent probes that address current limitations of NO detection. Transition metal based NO binding sites will be used to develop probes that can reversibly bind NO and probes that emit in the NIR. The proposed family of fluorescent probes will use paramagnetic (S=1/2) metals serving the dual role as both fluorescence quencher and NO binding site. Coordination of NO will form a diamagnetic (S=0) complex and restore the fluorescence of the pendant fluorophore. Adsorption or covalent attachment of such complexes to solubilized single-walled carbon nanotubes (SWNTs) will be used to develop NO-selective probes that emit in the NIR. The independent research phase of the proposed research will investigate the design of H2S-selective fluorescent probes for the imaging of endogenously produced H2S. Currently, such H2S detection methods are lacking and most measurements rely on bulk tissue measurements. The new H2S-selective fluorescent probes for use in live cells will provide much needed tools for the study of the biological functions of H2S. The unique physical properties of H2S will all be exploited in the design of H2S-selective fluorescent probes. Fluorophores will be derivatized with specially designed protecting groups that can only be removed by H2S. Removal of the fluorophore protecting group will restore the fluorescence, thus forming a turn-on probe for H2S.