title: The thrombin binding aptamer GGTTGGTGTGGTTGG forms a bimolecular guanine tetraplex.
abstract: In the literature, the thrombin binding aptamer GGTTGGTGTGGTTGG is generally taken as a prototype of an intramolecular guanine tetraplex of DNA. Our results, however, show that this notion is not true in aqueous solutions. This conclusion is based on a dependence of the CD spectra on aptamer concentration, migration of the aptamer in polyacrylamide gels, and the Ferguson analysis of the gel migration data. The presented data document that the aptamer forms a bimolecular tetraplex. We furthermore show that only an extension of the aptamer by a sequence containing further guanines, or an elongation of loop regions, causes that its tetraplex folding is intramolecular.
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-61265 Brno, Czech Republic.
authors.forename: Markéta
authors.initials: M
authors.lastname: Fialová
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Kypr
authors.forename: Michaela
authors.initials: M
authors.lastname: Vorlícková
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; C081676:thrombin aptamer; D006147:Guanine; D004247:DNA