摘要
Apurinic/apyrimidinic endonuclease 1（APE1） plays an important role in protecting the fidelity of genetic material and is also a promising biomarker of cancers. Herein, a simple and sensitive fluorescent method for APE1 activity detection was designed based on host-guest interaction between β-cyclodextrin polymer（β-CDP） and pyrene. In this method, pyrene-labelled DNA probes（AP-S1 S2） and β-CDP functioned as fluorescent signal producer and enhancer, respectively. When APE1 was absent, pyrene on the AP-S1 S2 could not enter the cavity of β-CDP because of steric hindrance, leading to a weak fluorescence intensity/anisotropy. When APE1 was present, it would recognize and cleave AP site in APS1 S2, thus producing a dissociated pyrene-labelled oligonucleotide segment. Pyrene labelled at the 50 end of oligonucleotide segment could be easily trapped into the cavity of β-CDP via host-guest interaction, leading to a significant enhancement of fluorescence intensity/anisotropy. This assay offered a dynamic range of 0.05 U/m L–5 U/m L and an estimated detection limit of 0.05 U/m L. Furthermore,assessment of APE1 activity in He La cell extracts was successfully implemented, which hold the potential for APE1-related cancer diagnosis and biological researches.
Apurinic/apyrimidinic endonuclease 1（APE1） plays an important role in protecting the fidelity of genetic material and is also a promising biomarker of cancers. Herein, a simple and sensitive fluorescent method for APE1 activity detection was designed based on host-guest interaction between β-cyclodextrin polymer（β-CDP） and pyrene. In this method, pyrene-labelled DNA probes（AP-S1 S2） and β-CDP functioned as fluorescent signal producer and enhancer, respectively. When APE1 was absent, pyrene on the AP-S1 S2 could not enter the cavity of β-CDP because of steric hindrance, leading to a weak fluorescence intensity/anisotropy. When APE1 was present, it would recognize and cleave AP site in APS1 S2, thus producing a dissociated pyrene-labelled oligonucleotide segment. Pyrene labelled at the 50 end of oligonucleotide segment could be easily trapped into the cavity of β-CDP via host-guest interaction, leading to a significant enhancement of fluorescence intensity/anisotropy. This assay offered a dynamic range of 0.05 U/m L–5 U/m L and an estimated detection limit of 0.05 U/m L. Furthermore,assessment of APE1 activity in He La cell extracts was successfully implemented, which hold the potential for APE1-related cancer diagnosis and biological researches.
基金
supported by the National Natural Science Foundation of China (Nos. 21675047, 21375034, 21190040)
the Foundation for Innovative Research Groups of National Natural Science Foundation of China (No. 21521063)
