title: Oligodeoxyribonucleotide length and sequence effects on intramolecular and intermolecular G-quartet formation.
abstract: The potential of guanine-rich oligodeoxyribonucleotides (oligos) as nucleic acid drugs is increasingly being investigated, for example, as aptamers against heparin-binding proteins and as purine-motif triplex-forming oligos. However, G-rich oligos can be very polymorphic under physiological conditions, often with the resulting structures possessing vastly different functional capabilities. To better understand the intrinsic oligo parameters that affect their structure, we used nondenaturing gel electrophoresis to investigate a series of G-rich oligos derived from the sequence 5'-TGGGTGGGGTGGGGTGGGT for their abilities to self-associate through G-quartet formation. From these studies the following observations could be made: (1) oligos containing four clusters of three or more contiguous Gs readily associated intramolecularly but did not associate intermolecularly; (2) intermolecular dimerization was the preferred mode of interaction when one of the oligos contained only two G clusters; and (3) T-rich extensions promoted multimerization of oligos into still higher-order species.
authors.affiliation: Department of Tumor Biology, University of Texas, M.D. Anderson Anderson Cancer Center, Houston 77030, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Cheng
authors.forename: M W
authors.initials: MW
authors.lastname: Van Dyke
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D003902:Detergents; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry*; D007700:Kinetics; D009690:Nucleic Acid Conformation; D017830:Octoxynol; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D011092:Polyethylene Glycols; D013816:Thermodynamics
chemical_list: D003902:Detergents; D009838:Oligodeoxyribonucleotides; D011092:Polyethylene Glycols; D006147:Guanine; D017830:Octoxynol; D004247:DNA; C010615:Nonidet P-40