NEW PROBES AND REAGENTS FOR BIOLOGICAL STUDIES

总体研究计划的中心主题是设计， 化学合成、表征和协同应用 新的探针和试剂，旨在克服一些 目前在生物和医学研究中严重的obsticals。 四个子领域构成了这个五年项目的重点。 （a）新的 用于磁共振成像的对比度增强剂。 的 长期目标是开发改进的、临床上可接受的 顺磁剂，选择性地增强对比度， 靶组织和器官的MRI应用。 为了 最大化造影剂的有效性， 大量的顺磁中心可以附着在 化学定义明确的方式将被合成。 “分子” 然后将“放大器”连接到靶向装置，e.例如，在一个实施例中，一个 抗体或脂质体，通过化学反应臂。因此， 可能能够实现良好的对比度与相对较小的 顺磁中心的数量。 放大器的概念预计 适用于其他领域，E。例如，在一个实施例中，硼-10中子俘获 疗法 扩增也将寻求通过合成 高顺磁性脂质体，并通过修饰 分子盒，脱铁铁蛋白。 B）用于单重态的新ESR探针 氧气 单线态氧可能是一种氧化剂， 生物系统中的光动力效应。 水溶性类似物 我们成功的蒽氮氧化物为基础的ESR单线态氧 这是需要的，这是我们的目标。 的意义 这一部分是为研究开发新的工具， 氧化是生物系统中的基本过程。 （c）新的 小型、高电子密度电子显微镜标签。 方法 将开发用于在我们的新的放射性标记中引入放射性标记， 基于杂多钨酸盐（HPT）的EM标记，允许独立的 生物系统中标记水平的定量。 我们打算 合成一种光标记的，HPT标记的ATP， 旨在确定ATP结合位点位置的研究 在F0 F1-ATP酶中，一种普遍存在的ATP合成酶。 d）合成 全氘代N-丙基氮氧化物自旋标记及其应用。 为了提高化学稳定性的灵敏度， 在我们的实验室开发的乙酰基氮氧自由基自旋标记，我们打算 开发一条合成全氘代-15 N-丙氧基化合物的简便路线。 一种化学性质明确的自旋标记磷脂酰肌醇（PI） 以及标记的膦酸酯类似物将被合成， 脂质-蛋白质协同生物物理研究 PI和膜蛋白之间的相互作用 与膜受体转导。

The central theme of the overqall research program is the design, chemical synthesis, characterization, and collaborative application of new probes and reagents designed to overcome some of the currently serious obsticals in biological and medical research. Four subareas form the focus of this five year project. a) New Contrast-Enhancing Agents for Magnetic Resonance Imaging. The long-term objective is to develop improved, clinically acceptable paramagnetic agents that selectively enhance the contrast of targety tissues and organs in MRI appplications. In order to maximize effectiveness of the contrast agent, moleccules to which a larage number of paramagnetic centers may be attached in a chemically well defined manner will be synthesized. The "molecular amplifier" is then attached to the targeting device, e. g., an antibody or liposome, through a chemically reactive arm. Thus, one might be able toachieve excellent contrast with a relatively small number of paramagnetic centers. The amplifier concept is expected to be applicable to other areas, e. g., boron-10 neutron capture therapy. Amplification wil also be sought through the synthesis of highly paramagnetic liposomes and through modification of the "molecular box", apoferritin. b) New ESR Probes for Singlet Oxygen. Singlet ocygen is a likely oxidant associated with the photodynamic effect in biological systems. A water soluble analog of our successful anthracene nitroxide-based ESR singlet oxygen probe is needed and this is our objective. The significance of thes segment is the development of new tools for the study of oxidation, a fundamental process in biological systems. c) New Small, Highly Electron Dense Electron Microscopy Labels. Methods will be developed for the introduction of a radiolabel in our new heteropolytungstate (HPT)-based EM labels, permitting independent quantitation of labeling levels in a biological system. We intend to synthesize a photolabeled, HPT-labeled ATP for a collaborative study aimed at determining the location of the ATP binding sites in F0F1-ATPase, a ubiquitous ATP-synthesizing enzyme. d) Synthesis and Applications of Perdeutero N-Proxyl Nitroxide Spin Labels. With the aim of enhancing the sensitivity of the chemically robust proxyl nitroxide spin labels developed in our laboratory, we intend to develop a convenient synthetic route to perdeutero-15N-proxyls. A chemically well defined spin labeled phosphatidylinositol (PI) as well as a labeled posphonate analog will be synthesized for collaborative biophysical investigation of lipid-protine interactions occurring between PI and membrane proteins associated with membrane recptor transduction.