Spectrofluorometry of Ions and Small Molecules Based on Conformational Changes of Specific Oligonucleotides with o-Phthalaldehyde-β-mercaptoethanol  

作　　者：LIAO Qie-gen WANG Jian LONG Yun-fei LI Yuan-fang 

机构地区：[1]Key Laboratory of Lumineseence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China [2]Key Laboratory of Quality and Safety of Agricultural Products, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, R R. China

出　　处：《Chemical Research in Chinese Universities》2010年第3期360-365,共6页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China(No.20775061)

摘　　要：Specific oligonucleotides such as telomere DNA and aptamer often undergo conformational changes upon ligand binding. Composite reagent composed of o-phthalaldehyde and β-mercaptoethanol（OPAME） has been extensively applied to fluorescent detection of amino compounds based on the reaction of primary amino-group, herein we proposed a general spectrofluorometry for ions and small molecules due to conformational changes upon ligand binding taking K^＋ and ATP as examples. In a borate controlled buffer medium, telomere DNA could react with OPAME, giving a thio-subtituted isoindole compound with strong fluorescence emission at 455 nm when excited at 340 nm. It was found that however, the fluorescence emission was greatly reduced in the presence of K^＋ since the formation of the quadruplex structure inhibits the reaction activity of amino-groups of telomere DNA. In order to testify the general application of OPAME reagent based on the conformational change of oligonucleotides, we further proposed a sensitive method of ATP based on its highly selective interaction with ATP-aptamer. The above mentioned applications show that the spectrofluorometry with the aid of OPAME reagent is simple, label free that is expected to be potentially general for DNA conformational change-based target detection.Specific oligonucleotides such as telomere DNA and aptamer often undergo conformational changes upon ligand binding. Composite reagent composed of o-phthalaldehyde and β-mercaptoethanol（OPAME） has been extensively applied to fluorescent detection of amino compounds based on the reaction of primary amino-group, herein we proposed a general spectrofluorometry for ions and small molecules due to conformational changes upon ligand binding taking K^＋ and ATP as examples. In a borate controlled buffer medium, telomere DNA could react with OPAME, giving a thio-subtituted isoindole compound with strong fluorescence emission at 455 nm when excited at 340 nm. It was found that however, the fluorescence emission was greatly reduced in the presence of K^＋ since the formation of the quadruplex structure inhibits the reaction activity of amino-groups of telomere DNA. In order to testify the general application of OPAME reagent based on the conformational change of oligonucleotides, we further proposed a sensitive method of ATP based on its highly selective interaction with ATP-aptamer. The above mentioned applications show that the spectrofluorometry with the aid of OPAME reagent is simple, label free that is expected to be potentially general for DNA conformational change-based target detection.

关 键 词：APTAMER O-PHTHALALDEHYDE β-Mercaptoethanol K^＋ Adenosine-5′-triphosphoric acid 

分 类 号：O614.33[理学—无机化学] S828[理学—化学]