Papp S, Vanderkooi J M
Photochem Photobiol. 1989 Jun;49(6):775-84. doi: 10.1111/j.1751-1097.1989.tb05576.x.
Fluorescence and phosphorescence resemble each other and in many ways can give the same type of information. Both originate from a dipolar interaction between light and the molecule. In this regard, both are polarized and subject to the same type of quenching phenomena. In other respects the information which they divulge are complementary. The fluorescence quantum yield is higher for exposed tryptophans and this is expressed in longer lifetime (Grinvald and Steinberg, 1976); in contrast long lifetime of phosphorescence appears to correlate with burial. Phosphorescence, spin-disallowed, is much longer lived than fluorescence. This allows the structural/dynamic characterization of proteins to be studied on a new time regime. A really remarkable finding of studies of protein phosphorescence is that there is such variability both in phosphorescence lifetime and quenchability. We would interpret this to indicate that the tryptophan environment can range from essentially a crystal, almost comparable in rigidity as found at 77 K, to tryptophans in a flexible environment, almost as flexible as free in solution. An interesting task will be to examine the relationship between the yield and lifetime of phosphorescence and details of the tryptophan environment in terms of rigidity and adjacent amino acids among the proteins with known three dimensional structure.
荧光和磷光彼此相似，在许多方面能够提供相同类型的信息。二者均源于光与分子之间的偶极相互作用。就此而言，二者都具有偏振性，并会受到相同类型的猝灭现象影响。在其他方面，它们所揭示的信息是互补的。对于暴露在外的色氨酸，荧光量子产率更高，这表现为更长的寿命（格林瓦尔德和斯坦伯格，1976年）；相反，磷光的长寿命似乎与埋藏有关。磷光由于自旋禁阻，其寿命比荧光长得多。这使得能够在新的时间尺度上研究蛋白质的结构/动力学特征。蛋白质磷光研究的一个非常显著的发现是，磷光寿命和可猝灭性都存在如此大的变异性。我们将此解释为表明色氨酸环境可以从本质上类似于晶体，其刚性几乎与在77K时发现的相当，到处于柔性环境中的色氨酸，几乎与溶液中的自由色氨酸一样柔性。一项有趣的任务将是根据具有已知三维结构的蛋白质的刚性和相邻氨基酸，研究磷光产率和寿命与色氨酸环境细节之间的关系。
