Aptamer Beacons for the Direct Detection of Proteins

✍ Scribed by Nobuko Hamaguchi; Andrew Ellington; Martin Stanton

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 148 KB
• Volume: 294
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.2001.5169

✦ Synopsis

We have designed a new class of molecules, which we term aptamer beacons, for detecting a wide range of ligands. Similar to molecular beacons, aptamer beacons can adopt two or more conformations, one of which allows ligand binding. A fluorescence-quenching pair is used to report changes in conformation induced by ligand binding. An anti-thrombin aptamer was engineered into an aptamer beacon by adding nucleotides to the 5'-end which are complementary to nucleotides at the 3'-end of the aptamer. In the absence of thrombin, the added nucleotides will form a duplex with the 3'-end, forcing the aptamer beacon into a stem-loop structure. In the presence of thrombin, the aptamer beacon forms the ligand-binding structure. This conformational change causes a change in the distance between a fluorophore attached to the 5'-end and a quencher attached to the 3'-end. Aptamer beacon can be a sensitive tool for detecting proteins and other chemical compounds.