A modular clamp-like mechanism to regulate the activity of nucleic-acid target-responsive nanoswitches with external activators

摘要

Herewedemonstrateageneralandmodularapproachtoregulateudtheactivityoftarget-responsiveDNA-basednanoswitches.Wedoudso by coupling together two DNA-based responsive elements: audtriplex-forming clamp-like probe able to bind a specific DNAudsequenceandasplitaptamerselectedtobindasmallmolecule.Inudthepresenceofthespecifictargetofoneoftheaboveresponsiveudelements,thenanoswitchpartiallyfoldsanditsabilityto bindtheudsecond target is restored. With this approach we can finelyudmodulate the affinity of both DNA-recognition elements andudaptamers using an external ligand. The modular nature of ourudstrategy makes it easily generalizable to different DNA basedudrecognition elements.Asademonstrationof thiswe successfullyuddesigned five different DNA nanoswitches whose responsivenessudcanberegulatedbydifferentmoleculareffectorsandtargets.Theudconveniencewithwhichthismechanismisdesignedsuggeststhatudit mayproveausefultoolbywhichsensors,geneticnetworksandudother biotechnology devices employing nucleic-acid basedudreceptorscanbecontrolledwithanexternalinput.