SYNTHETIC COMPOUNDS TO PROBE MOLECULAR EVENTS IN BIOLOGY

用于探测生物学分子事件的合成化合物

• 批准号: 3756013
• 负责人: VALERIA BALOGH-NAIR
• 金额: --
• 依托单位: CITY COLLEGE OF NEW YORK
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3756013
• 关键词: G protein; Raman spectrometry; chemical binding; chemical structure function; chemical synthesis; chromophore; high performance liquid chromatography; photochemistry; protein structure; rhodopsin; spectrometry; stereochemistry; visual photoreceptor

We propose an organochemical approach to determine molecular recognition elements that the visual photoreceptors employ to trigger the cascade of biochemical events, which culminate in neural responses. We are specifically interested in: 1) the nature of molecular events at the retinal chromophore's binding site in rhodopsins that enables the ultrafast photoisomerization and wavelength regulation, 2) the mechanisms of conformational changes of the rhodopsin, initiated by retinal isomerization, that in turn create a binding domain in the tertiary structure of rhodopsin, structurally optimized for photoactivated rhodopsin - G protein (transducin) interactions. Concerted efforts of several disciplines have been successful in elucidating many aspects of this information processing system but the tertiary structures of rhodopsin and its photoactivated form are not known. Knowledge of these tertiary structures are however, a prerequisite for understanding the mechanism of the sequence of events in a structural perspective, at the molecular level, 3) the structural make-up of the G protein binding site that requires guanine nucleotides and hitherto was difficult to investigate due to the lack of appropriately labeled nucleotide analogs. We propose to achieve our goals by incorporation of synthetic probes into rhodopsins and G proteins followed by studies of the properties of functional rhodopsin and G protein analogs generated. In the case of rhodopsin, novel type of spacer-armed retinals will be employed, and in the case of G protein, isotopically labeled and site specifically modified GDPs will be used as probes of the protein's structure. The structural information obtained from employing the probes described in this project will open up a whole new area of exploratory studies. For instance, development of domain-specific rhodopsin-immunoconjugates and site-specific rhodopsin-peptide conjugates will be possible. It will also pave the way to site-specific conjugation of rhodopsins to effect their crystallization and to effect their site-specific cleavage. In the case of the G protein, Raman spectroscopic investigation employing isotopically labeled GDP analogs will yield insight into the solution structure of the interaction domain(s) of the G with the protein. The organochemical approach in this project will thus have a major impact in the area of sensory transduction, where molecular level investigations can make unique contributions towards the elucidation of the cellular events in precise structural terms, by identifying the molecular domains and chemical mechanisms involved in the activation of excitable membranes.

我们提出了一种确定分子识别的有机方法 视觉光感受器触发级联的元素 生化事件，最终导致神经反应。 我们是 特别感兴趣：1）在 视网膜发色团的结合位点在视紫红蛋白中的结合位点使得 超快光异构化和波长调节，2）机制 视网膜引发的视紫红质的构象变化 异构化，这又在第三级创建一个结合域 视紫红质的结构，用于光活化的结构优化 Rhodopsin -G蛋白（透明蛋白）相互作用。 一致的努力 几个学科已经成功地阐明了 此信息处理系统，但 视紫红质及其光活化形式尚不清楚。 了解这些 但是，三级结构是理解的先决条件 在结构的角度，在结构上的机理 分子水平，3）G蛋白结合位点的结构构成 这需要鸟嘌呤核苷酸，迄今为止很难 由于缺乏适当标记的核苷酸类似物而进行的研究。 我们建议通过将合成探针纳入到 Rhodopsins和G蛋白，然后研究 产生功能性视紫红质和G蛋白类似物。 如果是 Rhodopsin，将采用新型的间隔视网膜类型，并在 G蛋白的情况，同位素标记和特定位置 修饰的GDP将用作蛋白质结构的探针。 这 通过采用描述的探针获得的结构信息 该项目将开辟一个全新的探索性研究领域。 为了 实例，开发域特异性的Rhopopsin-rumunoconjugates和 位点特异性的视紫红蛋白肽结合将有可能。 会 还为视紫红蛋白的特定地点结合铺平了道路 它们的结晶并影响其特定地点的裂解。 在 G蛋白的病例，拉曼光谱研究采用 同位素标记的GDP类似物将产生对溶液的见解 G与蛋白质的相互作用结构域的结构。 因此，该项目中的有机化学方法将产生重大影响 在感觉转导的区域，分子水平研究 可以为阐明细胞做出独特的贡献 通过识别分子结构域的精确结构术语事件 和激活可激活的化学机制 膜。