TRIPLET STATE PHOTOPHYSICS OF TRYPTOPHAN & TRYPTOPHAN ANALOGS

色氨酸磷光已经使用了20多年， 研究蛋白质在生理条件下的构象和柔性 条件 这项研究的基础是 色氨酸三重态对分子猝灭的敏感性 蛋白质弹性（Protein Flexibility） 的三重态电子物理 色氨酸和它的类似物是不充分的理解;很少有人知道 碰撞淬火的实际物理机制 三重态，几乎对三重态一无所知 色氨酸类似物的光物理学和非辐射衰变（其可以 在体内被掺入蛋白质中以产生光谱增强的 蛋白质）。 这个项目将研究三重态 色氨酸及其类似物在室温下玻璃态的电子物理 糖基质和温度和粘度对这些的影响 性质，其他研究将测定氘的影响 对色氨酸的非辐射衰变进行替代， C-H拉伸/弯曲模式对T向S推进的影响 过渡 荧光三重态量子产率的测量 状态形成，磷光将与寿命相结合 测量，以生成完整的地球物理特性， 这一重要的生物学类别的激发态电子物理学 发色团 详细比较了 刚性（玻璃糖）和移动的（粘性溶液）环境将 允许评估由于碰撞导致的猝灭速率常数， 色氨酸和每种类似物。

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.