James D R, Demmer D R, Steer R P, Verrall R E
Biochemistry. 1985 Sep 24;24(20):5517-26. doi: 10.1021/bi00341a036.
The time-resolved fluorescence of the lone tryptophanyl residue of ribonuclease T1 was investigated by using a mode-locked, frequency-doubled picosecond dye laser. The fluorescence decay could be characterized by a single exponential function with a lifetime of 3.9 ns. The fluorescence was readily quenched by uncharged solutes but was unaffected by iodide ion. These observations are interpreted in terms of the electrostatic properties of the amino acid residues at the active site of the protein, which would appear to restrict the access of solute species to the tryptophanyl residue. The temperature dependence of the fluorescence lifetime and anisotropy decay time could be rationalized in terms of a model which postulates a significant ordering of the solvent layer immediately surrounding the surface of the protein.
利用锁模倍频皮秒染料激光器研究了核糖核酸酶T1中单个色氨酸残基的时间分辨荧光。荧光衰减可用寿命为3.9 ns的单指数函数表征。荧光很容易被不带电荷的溶质淬灭，但不受碘离子影响。这些观察结果根据蛋白质活性位点氨基酸残基的静电性质进行了解释，这似乎限制了溶质分子接近色氨酸残基。荧光寿命和各向异性衰减时间的温度依赖性可以根据一个假设蛋白质表面紧邻的溶剂层有显著有序排列的模型来解释。
