THE TRYPTOPHAN FLUORESCENCE LIFETIME PUZZLE - A STUDY OF DECAY TIMES IN AQUEOUS-SOLUTION AS A FUNCTION OF PH AND BUFFER COMPOSITION
THE TRYPTOPHAN FLUORESCENCE LIFETIME PUZZLE - A STUDY OF DECAY TIMES IN AQUEOUS-SOLUTION AS A FUNCTION OF PH AND BUFFER COMPOSITION
复制标题
DOI：
10.1139/v81-154
复制
发表时间：
1981-01-01
影响因子：
1.1
通讯作者：
WARE, WR
中科院分区：
文献类型：
--
作者：
GUDGIN, E;LOPEZDELGADO, R;WARE, WR
色氨酸荧光衰减动力学系统地研究了在水溶液中作为pH值的函数，以及在各种缓冲溶液中。在pH 7.0以下，衰减似乎是双指数的，具有亚纳秒分量，证实了Rayner和Szabo先前的发现。在低pH区域，其中质子浓度变得动力学显著，色氨酸荧光被[H+]以扩散控制速率碰撞淬灭，并且没有发现关于在低pH下出现新的色氨酸分子物种（即阳离子形式）的实验证据。在pH ≥7.0，衰减成为三倍指数的外观的一个长的组件，其贡献的总发射强度迅速增加，随着pH值的增加，在其他2的费用。每个衰变组分的寿命和相对强度以复杂的方式取决于pH值和缓冲液的化学组成。
Tryptophan fluorescence decay kinetics were systematically investigated in aqueous solutions as a function of pH as well as in a variety of buffer solutions. Below pH 7.0, the decay appears to be double exponential with a subnanosecond component confirming the previous findings of Rayner and Szabo. In the low pH region, where the proton concentration becomes kinetically significant, tryptophan fluorescence is collisionally quenched by [H+] with diffusion controlled rate and no experimental evidence is found regarding the appearance at low pH of a new tryptophan molecular species, namely the cationic form. At pH .gtoreq. 7.0, the decay becomes triple-exponential with the appearance of a long component whose contribution to the total emission intensity increases rapidly with increasing pH at the expense of the other 2. Lifetimes and relative intensities of each decay component depend in a complex way on pH and on the buffer chemical composition.