No Structure-Switching Required: A Generalizable Exonuclease-Mediated Aptamer-Based Assay for Small-Molecule Detection.

ABSTRACT: The binding of small molecules to double-stranded DNA can modulate its susceptibility to digestion by exonucleases. Here, we show that the digestion of aptamers by exonuclease III can likewise be inhibited upon binding of small-molecule targets and exploit this finding for the first time to achieve sensitive, label-free small-molecule detection. This approach does not require any sequence engineering and employs prefolded aptamers which have higher target-binding affinities than structure-switching aptamers widely used in current small-molecule detecting assays. We first use a dehydroisoandrosterone-3-sulfate-binding aptamer to show that target binding halts exonuclease III digestion four bases prior to the binding site. This leaves behind a double-stranded product that retains strong targ

SUBMITTER: Canoura J 

PROVIDER: S-EPMC6133295 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature