Fluorescence dynamics of N-terminal Trp–Trp residues in polypeptide: intrinsic indicators for monitoring p H  

作　　者：Lei Li Hua Yi Mengfang Chang Xiaodan Cao Zhongneng Zhou Cuifang Qin Sanjun Zhang Haifeng Pan Yan Chen Jianhua Xu 

机构地区：[1]State Key Laboratory of Precision Spectroscopy, East China Normal University [2]Tongji Hospital Affiliated to Tongji University

出　　处：《Science Bulletin》2015年第24期2129-2134,共6页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(61108077;61178085);the Science and Technology Commission of Shanghai Municipality(15520711500;15ZR1411700);the Program of Introducing Talents of Discipline to Universities(B12024)

摘　　要：pH plays a vital role in various cellular activities, and real-time observation of the intracellular p H through a p H indicator is very important for studying many physiological processes. In this paper, we studied the p H response of Trp–Trp dipeptide and its derivatives(NATrp_2Me, NBTrp_2 and Trp_2Me) by steady-state and time-resolved fluorescence spectroscopy. Both the fluorescence intensities and lifetimes of Trp–Trp dipeptide as well as Trp2 Me were functions of p H in the physiological range from 5.5 to 9.0. However, NATrp_2 Me and NBTrp_2 showed no difference. The exposed amino was found to be pivotal for its p H dependence. Moreover, an artificially synthesized tetrapeptide(Trp–Trp–Ala–Ser) confirmed the p H sensitivity of N-terminal Trp–Trp residues. The p H values could be quantitatively determined from the fluorescence intensities and lifetimes of the N-terminal Trp–Trp residue. Thus, the N-terminal Trp–Trp residues may be fused into the polypeptides/proteins to serve as an intrinsic p H indicator in fluorescence spectroscopy and imaging.pH plays a vital role in various cellular activities, and real-time observation of the intracellular pH through a pH indicator is very important for studying many physiological processes. In this paper, we studied the pH response of Trp-Trp dipeptide and its derivatives （NATrp2Me, NBTrp2 and Trp2Me） by steady-state and time-resolved fluorescence spectroscopy. Both the fluorescence intensities and lifetimes of Trp-Trp dipeptide as well as Trp2Me were functions of pH in the physiological range from 5.5 to 9.0. However, NATrp2Me and NBTrp2 showed no difference. The exposed amino was found to be pivotal for its pH dependence. Moreover, an artificially synthesized tetrapeptide （Trp-Trp-Ala-Ser） confirmed the pH sensitivity of N-terminal Trp-Trp residues. The pH values could be quantitatively determined from the fluorescence intensities and lifetimes of the N-terminal TrpTrp residue. Thus, the N-terminal Trp-Trp residues may be fused into the polypeptides/proteins to serve as an intrinsic pH indicator in fluorescence spectroscopy and imaging.

关 键 词：Trp-Trp dipeptide FluorescenceIntrinsic pH sensors 

分 类 号：Q51[生物学—生物化学]