Femtosecond Studies of Tryptophan Fluorescence Dynamics in Proteins: Local Solvation and Electronic Quenching
详细信息 查看全文
- 作者：Luyuan Zhang ; Ya-Ting Kao ; Weihong Qiu ; Lijuan Wang ; Dongping Zhong
- 刊名：Journal of Physical Chemistry B
- 出版年：2006
- 出版时间：September 21, 2006
- 年：2006
- 卷：110
- 期：37
- 页码：18097 - 18103
- 全文大小：2195K
- 年卷期：v.110,no.37(September 21, 2006)
- ISSN：1520-5207
文摘
We report our systematic examination of tryptophan fluorescence dynamics in proteins with femtosecondresolution. Distinct patterns of femtosecond-resolved fluorescence transients from the blue to the red side ofemission have been characterized to distinguish local ultrafast solvation and electronic quenching. It is shownthat tryptophan is an ideal local optical probe for hydration dynamics and protein-water interactions as wellas an excellent local molecular reporter for ultrafast electron transfer in proteins, as demonstrated by a seriesof biological systems, here in melittin, human serum albumin, and human thioredoxin, and at lipid interfaces.These studies clarify the assignments in the literature about the ultrafast solvation or quenching dynamics oftryptophan in proteins. We also report a new observation of solvation dynamics at far red-side emissionwhen the relaxation of the local environment is slower than 1 ps. These results provide a molecular basis forusing tryptophan as a local molecular probe for ultrafast protein dynamics in general.