Molecular Assembly of Superquenchers in Signaling Molecular Interactions

摘要

We have designed a novel molecular assembly of quencher molecules to form superquenchers with excellent quenching efficiency. The superquencher can be engineered as desired by assembling different types and different numbers of quencher molecules. By labeling a superquencher to an MB, a 320-fold enhancement of fluorescent signal was achieved, compared to about 14-fold from an MB prepared with the same monomer quencher. The molecular assembly approach has three distinguished features. (1) The assembled superquencher shows unique properties for use in engineering molecular probes. Compared with a regular MB, a SQ-constructed MB has better sensitivity, better purity, higher thermal stability, and slightly improved specificity. (2) The assembly scheme can be widely useful for different types of quencher molecules. (3) The SQ can be used for different fluorophores and in different probes. The SQs used for signaling aptamer -protein interactions have generated more than a 49 000-fold signal change when a PDGF aptamer was bound to PDGF. No detrimental effect of these SQs on the performance of probes was observed. The SQ MB showed hybridization kinetic properties similar to that of the regular MB. Our molecular assembly approach can effectively improve the sensitivity of a variety of fluorescent assays and may be widely useful for molecular recognition and interaction studies.