title: Facile conversion of aptamers into sensors using a 2'-ribose-linked fluorophore.
abstract: In vitro selection can be used to identify nucleic acid receptors, called aptamers, that bind diverse small molecule targets. Aptamers therefore represent an attractive platform for creating sensors. Here, we report a straightforward, semi-rational approach for converting arbitrary aptamers into reagentless, single fluorophore biosensors. The local electrostatic environment at the 2'-ribose position is exquisitely sensitive to whether a nucleotide is conformationally restrained or not. Thus, by tethering an environmentally sensitive fluorescent group at an appropriate 2'-ribose group, we are able to generically detect ligand-induced conformational changes in aptamers. Three aptamers, including one for which no significant structural information can be inferred, were converted into robust small molecule sensors that function well in simple buffers, human urine, and bovine blood serum.
authors.affiliation: Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Merino
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Weeks
mesh_terms: D015374:Biosensing Techniques; D001896:Boron Compounds / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry*; D012266:Ribose / Q000737:chemistry*
chemical_list: D001896:Boron Compounds; D005456:Fluorescent Dyes; D008024:Ligands; D009841:Oligonucleotides; D012266:Ribose