INTRINSIC FLUORESCENCE DECAY MECHANISMS OF PROTEINS

蛋白质的内在荧光衰变机制是一种多层次的 调查员，结合时间分辨的多学科项目 核磁共振荧光和分子模拟。我们的目标是 确定三种芳香族化合物的时间分辨荧光 色氨酸、酪氨酸和苯丙氨酸可用于 获取有关结构和构象动力学的信息 蛋白质。这需要了解如何以及在多大程度上 基态和激发态过程影响荧光 强度衰减动力学。核磁共振被用来帮助定义 重要的基态过程。分子模拟，基于X- 射线晶体结构，正被用来计算 芳香族氨基酸的本地环境与 从荧光和核磁共振中得到结论。在这首字母中 授权期内，我们正在研究定义明确、简单的多肽和 具有单一芳香族氨基酸的多肽类似物 系统地在每个芳香族氨基酸中取代相同的 在多肽链中的位置。这些关于多肽和 多肽是扩大研究范围的基础 几种结构上相关的单一酪氨酸蛋白。结果是 这种跨学科的方法，强调酪氨酸 荧光，将通过继续应用，用于 将这一研究扩展到蛋白质的色氨酸荧光。 这项工作将进一步加深我们对时间分辨的理解 芳香族残基的荧光，大大增加了我们的 关于溶液结构和构象动力学的知识 蛋白质，并使时间分辨荧光技术 分析蛋白质结构的有力工具。

Intrinsic Fluorescence Decay Mechanisms of Proteins is a multi- investigator, multidisciplinary project combining time-resolved fluorescence with NMR and molecular modeling. Our objective is to determine how time-resolved fluorescence of the three aromatic amino acids tryptophan, tyrosine, and phenylalanine can be used to obtain information about structure and conformational dynamics of proteins. This requires understanding how and to what extent ground-state and excited-state processes affect the fluorescence intensity decay kinetics. NMR is being used to help define important ground-state processes. Molecular modeling, based on X- ray crystal structures, is being used to compute properties of an aromatic amino acid's local environment for comparison with the conclusions obtained from fluorescence and NMR. In this initial grant period we are investigating well-defined, simple peptide and polypeptide analogues having a single aromatic amino acid by systematically substituting in each aromatic amino acid at the same position in the peptide chain. These studies on peptides and polypeptides are the basis for extending the investigation into several structurally related single-tyrosine proteins. The results of this interdisciplinary approach, emphasizing tyrosine fluorescence, will be used, through a continuation application, to extend this investigation to tryptophan fluorescence of proteins. This work will further our understanding of the time-resolved fluorescence of the aromatic residues, add significantly to our knowledge of the solution structure and conformational dynamics of proteins, and make time-resolved fluorescence techniques a more powerful tool for analyzing protein structure.