MECHANISM OF VISUAL EXCITATION

视觉兴奋机制

• 批准号: 2158119
• 负责人: THOMAS G EBREY
• 金额: $ 22.94万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-30 至 1995-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2158119
• 关键词: Anura; Raman spectrometry; alternatives to animals in research; bioenergetics; biological signal transduction; biophysics; cations; chromophore; cone cell; conformation; cyclic GMP; electrical potential; fluorescence; fresh water environment; guanosine diphosphate; guanosine triphosphate; laboratory mouse; light adaptations; membrane activity; monoclonal antibody; neurotransmitters; nuclear magnetic resonance spectroscopy; photochemistry; protein sequence; proton beam; retina; rhodopsin; tissue /cell culture; transducin; vision; visual photoreceptor; visual stimulus

Our long term goal is to elucidate the biochemical and biophysical mechanisms underlying visual excitation and photoreceptor metabolism. Our approach is to attack important, related problems at several organizational levels of the photoreceptor cell. These levels are first, the visual pigments themselves, especially chicken cone pigments where, besides establishing their amino acid sequences, we plan to purify and study the pigments biophysically (vibrational spectra, bleaching kinetics). Second, at the level of the action of light on the pigments, we will seek to learn the nature of the storage of the photon's energy by the primary photoproduct, bathorhodopsin, and the properties of metarhodopsin II which allows it to interact with and activate the GTP binding protein, transducin. Third is the level of the photoreceptor membrane. We want to measure and study the control of the surface potential of photoreceptor membranes, since the surface potential will have profound effects on the concentration of charged substrates (e.g. cGMP), co-factors (e.g. GRP), and enzymes (e.g. transducin) near the surface of photoreceptor membranes where activation and some subsequent enzymatic events takes place. We also plan on clarifying the topology of rhodopsin in the membrane and will purify cone photoreceptor membranes. Fourth, is the level photoreceptor cell, especially with regard to the transduction machinery itself, and the transmitters and other key small molecules within the retinal cells. Here we will utilize new approaches to transducin (Raman difference spectroscopy, cation binding, meta II initiated conformational changes) and the use of phosphorus 31 NMR spectroscopy to study intracellular transmitters and metabolites in vivo. This integrated approach will offer not only new insight into visual excitation and the control of retinal metabolism, but also lead to the development of new and more sensitive ways to assay the health and metabolic state of the retina in vivo.

我们的长期目标是阐明生化和生物物理 视觉激发和光感受器代谢的基础机制。 我们的 方法是在几个组织中攻击重要的相关问题 感光细胞的水平。 这些级别首先是视觉 颜料本身，尤其是鸡锥色素，此外 建立他们的氨基酸序列，我们计划净化和研究 颜料生物物理（振动光谱，漂白动力学）。 第二， 在颜料对颜料的动作层面上，我们将寻求学习 主要的光子能量存储的性质 光产物，沐浴狂蛋白和metarhopopsin II的特性 允许它与GTP结合蛋白相互作用并激活 透明素。 第三是感光膜的水平。 我们想 测量和研究光感受器的表面电势的控制 膜，因为表面电位将对 带电底物的浓度（例如CGMP），副因素（​​例如GRP）和 光感受器膜表面附近的酶（例如转霉素）其中 激活和随后的一些酶促事件发生。 我们也计划 阐明膜上的视紫红质的拓扑结构并将净化 锥光受体膜。 第四，是水平的感光细胞， 特别是关于转导机械本身的 视网膜细胞内的发射器和其他关键小分子。 这里 我们将利用新方法进行转霉素（拉曼差异 光谱，阳离子结合，元II引发构象变化）和 使用磷31 NMR光谱研究细胞内 在体内发射器和代谢物。 这种综合方法将提供 不仅对视觉激发和视网膜控制的新见解 新陈代谢，但也导致了新的，更敏感的方式的发展 分析体内视网膜的健康和代谢状态。