NEW PROBES AND REAGENTS FOR BIOLOGICAL STUDIES

首席调查员总体研究计划的中心主题 是设计、化学合成、表征和协作 新探针、新试剂在生物学研究中的应用 系统。五个分领域构成了这一五年计划的重点。A)新增 基于氮氧化物的分子pH指示剂。室内pH值的测量 细胞和囊泡是许多生物学研究的基础 流程。我们建议将我们的阿尔法-氨基氮氧化物系列扩展为 依赖于pH的ESR超精细分裂常数An包括 在pH值为6-8的范围内有最佳反应。B)新的氮氧化物取代冠醚 乙醚。细胞内钠离子和钠离子活性的测定 钾离子是膜离子转运分子研究的中心 细胞生物学中的过程。我们设想了一系列氮氧化物自旋标记 冠醚和密码，其中的一个是敏感的活动 生理活性浓度范围内的金属离子， 建立一种新的、高灵敏的测定离子的ESR方法 活动。C)新的高度电子密度的小型EM标签。高分辨率 EM生物学研究需要开发更小的、高度电子的 能够附着在大分子上特定位置的致密标记。 有机官能化杂多钨离子在这方面有很好的前景 敬重。其中几种标记的合成和应用是 建议。D)一种新的单线态氧ESR探头。单氧是一种 生物中与光动力效应相关的可能氧化剂 系统。我们打算开发出作为灵敏电子自旋共振的氮杂菲。 通过与ESR相关的过氧化产物的形成来探测这种氧化剂 光谱变化。E)新的基于氮氧化物的核磁共振全身医学成像 特工。核磁共振在全身医学成像中的应用正在进行中 爆炸性发展。增强器官之间对比度的试剂有 需要的。如果抵抗原位还原，氮氧化物可能是答案 可以嵌入到分子中。这是我们的目标。它的意义 这项研究项目的一部分是使新的分子成为可能 旨在克服目前生物学领域中的一些严重障碍 和医学研究。

The central theme of the principal investigator's overall research program is the design, chemical synthesis, characterization and collaborative application of new probes and reagents for the study of biological systems. Five subareas form the focus of this five year project. a) New Nitroxide-Based Molecular pH Indicators. The measurement of pH inside cells and vesicles is fundamental to the study of many biological processes. We propose to extend our series of Alpha-amino notroxides with pH dependent ESR hyperfine splitting constants aN to include those which respond optimally in the range pH 6-8. b) New Nitroxide Substituted Crown Ethers. Measurement of the intracellular activities of sodium and potassium ions is central to molecular studies of membrane ion transport processes in cell biology. We envisage a series of nitroxide spin labeled crown ethers and cryptands in which aN is sensitive to the activity of the metal ion in the physiologically interesting concentration range, constituting a new, highly sensitive ESR method for determination of ion activities. c) New Small Highly Electron Dense EM labels. High resolution EM biological studies require the development of smaller, highly electron dense labels capable of attachment to specific sites on a macromolecule. Organic functionalized heteropolytungstate ions hold high promise in this regard. The synthesis and application of several of these labels is proposed. d) A New ESR Probe for Singlet Oxygen. Single oxygen is a likely oxidant associated with the photodynamic effect in biological systems. We intend to develop anthracene nitroxides as sensitive ESR probes for this oxidant through endoperoxide formation with associated ESR spectral changes. e) New Nitroxide-Based NMR Whole Body Medical Imaging Agents. The use of NMR for whole body medical imaging is undergoing explosive development. Agents which enhance contrast between organs are needed. Nitroxides may be the answer if resistance to in situ reduction can be built into the molecules. This is our objective. The significance of this research project is to make available new molecules which have been designed to overcome some of the currently serious obstacles in biological and medical research.