Barcellona M L, Gratton E
Department of Physics, University of Illinois, Urbana-Champaign 61801.
Biophys Chem. 1991 Jul;40(3):223-9. doi: 10.1016/0301-4622(91)80022-j.
The photophysical mechanisms which determine the spectral properties and decay rates of 4',6-diamidine-2-phenylindole (DAPI) in solution and in association with nucleic acids have not yet been fully elucidated. We have performed steady-state and time-resolved fluorescence experiments on DAPI in a wide pH range to investigate the hypothesis that different ground-state conformations are responsible for the photophysical properties of the probe. Several excited-state mechanisms are investigated and it is concluded that among the proposed models, the hypothesis of ground-state heterogeneity with rapid interconversion among conformations is the only one consistent with the experiments in the entire pH range investigated.
决定4',6-二脒基-2-苯基吲哚（DAPI）在溶液中以及与核酸结合时的光谱特性和衰减速率的光物理机制尚未完全阐明。我们在很宽的pH范围内对DAPI进行了稳态和时间分辨荧光实验，以研究不同基态构象决定该探针光物理性质的假说。研究了几种激发态机制，得出的结论是，在所提出的模型中，基态具有构象间快速相互转化的不均一性这一假说是唯一与在所研究的整个pH范围内的实验结果相一致的。
