TRIPLET STATE PHOTOPHYSICS OF TRYPTOPHAN & TRYPTOPHAN ANALOGS

色氨酸的三重态光物理学

• 批准号: 6328033
• 负责人: R D LUDESCHER
• 金额: $ 0.05万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6328033
• 关键词: biological products; biomedical resource; proteins

Tryptophan phosphorescence has been used for over 20 years to study the conformation and flexibility of proteins under physiological conditions. The basis for this research has been the extraordinary sensitivity of the tryptophan triplet state to quenching by molecular collisions (protein flexibility). The triplet state photophysics of tryptophan and its analogs is inadequately understood; little is known of the actual physical mechanism by which collisions quench the triplet state and almost nothing is known about the triplet state photophysics and non-radiative decay of tryptophan analogs (which can be incorporated into proteins in vivo to generate spectrally enhanced proteins). This project will investigate the triplet state photophysics of trp and trp analogs at room temperature in glassy sugar matrixes and the effect of temperature and viscosity on these properties, additional studies will assay the effect of deuterium substitution on non-radiative decay of try ptophan to evaluate the influence of C-H stretch/bending modes on promoting the T to S transition. Measurements of quantum yields for fluorescence, triplet state formation, and phosphorescence will be combined with lifetime measurements to generate a complete photophysical characterization of the excited state photophysics of this important class of biological chromophores. Detailed comparison of the photophysical behavior in rigid (glassy sugar) and mobile (viscous solution) environments will allow evaluation of the quenching rate constant due to collisions for tryptophan and each of the analogs.

色氨酸磷光已经使用了20多年来 生理条件下蛋白质构象和柔韧性的研究 条件。这项研究的基础是非同寻常的 色氨酸三重态对分子猝灭的敏感性 碰撞(蛋白质灵活性)。分子的三重态光物理 色氨酸及其类似物知之甚少；知之甚少 碰撞使之熄灭的实际物理机制 三重态，而对三重态几乎一无所知 色氨酸类似物的光物理学和非辐射衰变 在体内被结合到蛋白质中以产生光谱增强的 蛋白质)。这个项目将调查三重态 色氨酸及其类似物在玻璃中的室温光物理 糖的基质以及温度和粘度对它们的影响 性质，更多的研究将分析氢的影响 用Try-Ptophan的非辐射衰变替代来评价 C-H拉伸/弯曲模式对提升T到S的影响 过渡。三重态荧光量子产额的测量 态的形成，磷光将与寿命相结合 测量以生成完整的光物理表征 这类重要生物的激发态光物理 生色团。光物理行为的详细比较 刚性(玻璃糖)和流动(粘性溶液)环境将 允许评估因碰撞而导致的猝灭速率常数 色氨酸和每种类似物。