物理化学学报 >> 2015, Vol. 31 >> Issue (9): 1787-1794.doi: 10.3866/PKU.WHXB201507241

光化学和辐射化学 上一篇    下一篇

酪氨酸猝灭Eosin Y的荧光

王经东,李爽,吕荣,于安池()   

  • 收稿日期:2015-04-17 发布日期:2015-09-06
  • 基金资助:
    国家自然科学基金(21373269)

Fluorescence Quenching of Eosin Y by Tyrosine

Jing-Dong. WANG,Shuang. LI,Rong. LÜ,An-Chi. YU()   

  • Received:2015-04-17 Published:2015-09-06
  • Supported by:
    the National Natural Science Foundation of China(21373269)

摘要:

氨基酸残基对探针分子的荧光猝灭行为可以为生物大分子的结构及构象动力学研究提供重要的信息.本文运用飞秒瞬态吸收光谱和时间相关单光子计数实验系统研究了在水(H2O)和氘代水(D2O)溶液中乙酰基取代酪氨酸(AcTyr)对Eosin Y的超快荧光猝灭动力学过程.发现导致AcTyr对Eosin Y荧光猝灭的主要原因是由于它们之间形成了短寿命的基态复合物.我们还发现Eosin Y与AcTyr形成的基态复合物的激发态寿命具有明显的动力学同位素效应,表明AcTyr对Eosin Y的荧光猝灭是通过质子耦合电子转移过程发生的.

关键词: 飞秒瞬态吸收光谱, 时间相关单光子计数, 基态复合物, 酪氨酸猝灭, 质子耦合电子转移

Abstract:

Quenching of a fluorescent probe by amino acid residues can provide valuable information about the structural and conformational dynamics of a biopolymer. Herein, we systematically investigated the ultrafast fluorescence quenching dynamics of Eosin Y in the presence of N-acetyl-tyrosine (AcTyr) in H2O and D2O solutions using both femtosecond transient absorption and time-correlated single-photon counting experiments. We found that the quenching of the fluorescence of Eosin Y by AcTyr in aqueous solution is mainly because of the formation of a ground-state complex between Eosin Y and AcTyr. We also found that the lifetime of the ground-state complex formed between Eosin Y and AcTyr showed a clear kinetic isotope effect, indicating that the quenching of the fluorescence of Eosin Y by AcTyr in aqueous solution is via a proton-coupled electron transfer process.

Key words: Femtosecond transient absorption spectroscopy, Time-correlated single-photon counting, Ground-state complex, Tyrosine quenching, Proton-coupled electron transfer

MSC2000: 

  • O643