SPECTROSCOPIC STUDIES OF VISUAL PIGMENTS

视觉颜料的光谱研究

• 批准号: 3262628
• 负责人: BRYAN E KOHLER
• 金额: $ 14.44万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-04 至 1995-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3262628
• 关键词: chemical models; cholecalciferol; cis trans isomerization; electronic spectra; ionization; laser spectrometry; molecular dynamics; photochemistry; polyenes; retinoids; rhodopsin; spectrometry; visible light; visual pigments

This research is part of a general program to measure the electronic structure of biologically important molecules in those instances where there is good evidence that the electronic structure is essential to the biological function. The present work is concerned with polyene photoisomerization in the visual pigment and vitamin D 3. In order to understand the process of vision on a microscopic scale it is necessary to determine the nature of the interactions between opsin and retinal, both before and after the absorption of a photon. This description in turn rests on a detailed description of the electronic states of the visual pigments and their behavior under perturbation. This description is to be derived from measurements of the optical absorption and emission spectra of model systems and rhodopsin. A similar situation holds for vitamin D3 and its precursors. The emphasis is on developing new information by exploiting recent advances in polyene electronic structure and the application of tunable lasers to solve spectroscopic problems. This proposal describes experiments aimed at 1) Determining those 1-photon and 2-photon spectra for hexatriene and butadiene that are needed to establish the relative energies and conformations of the low lying excited singlet states, especially the 2(1)A(g) state. 2) Measuring fully resolved spectra for retinal derivatives seeded in supersonic helium expansions. 3) Elaborating the mechanism by which the model polyene octatetraene photoisomerizes in a condensed phase molecular cavity. 4) Extending these high resolution spectroscopic analyses to rhodopsin through measurements of photochemical hole burning.

这项研究是测量电子的一般计划的一部分 在那些情况下，生物学上重要的分子的结构 有充分的证据表明电子结构对 生物功能。目前的工作与多烯有关 视觉色素和维生素D 3中的光异构化。 为了理解微观量表的视觉过程，这是 确定Opsin和Opsin和 视网膜，在吸收光子之前和之后。此描述 反过 视觉颜料及其在扰动下的行为。此描述是 源自光吸收和发射的测量 模型系统和视紫红质的光谱。类似情况也适合 维生素D3及其前体。重点是开发新的 通过利用多烯电子结构的最新进展来提供信息 以及可调激光器在解决光谱问题上的应用。 该提案描述了针对1）确定1份的实验 以及六芳烯和丁二烯的2光子光谱 建立低躺式兴奋的相对能量和构象 单线表，尤其是2（1）A（g）状态。 2）测量完全解决的 视网膜衍生物的光谱在超音速氦膨胀中。 3） 阐述模型多烯八烯的机制 光异构体在凝结的相分子腔中。 4）扩展这些 高分辨率光谱分析通过测量 光化学孔燃烧。