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 ...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.展开更多
基金Supported by the National Natural Science Foundation of China(No.20775061)
文摘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.
