Spectroscopic sensing and quantification of AP-endonucleases using fluorescence-enhancement by cis-trans isomerization of cyanine dyes.

ABSTRACT: Apurinic/apyrimidinic (AP) endonucleases are vital DNA repair enzymes, and proposed to be a prognostic biomarker for various types of cancer in humans. Numerous DNA sensors have been developed to evaluate the extent of nuclease activity but their DNA termini are not protected against other nucleases, hampering accurate quantification. Here we developed a new fluorescence enhancement (FE)-based method as an enzyme-specific DNA biosensor with nuclease-protection by three functional units (an AP-site, Cy3 and termini that are protected from exonucleolytic cleavage). A robust FE signal arises from the fluorescent cis-trans isomerization of a cyanine dye (e.g., Cy3) upon the enzyme-triggered structural change from double-stranded (ds)DNA to single-stranded (ss)DNA that carr

SUBMITTER: Cho J 

PROVIDER: S-EPMC8695990 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature