title: Combining nucleoside analogues to achieve recognition of oligopurine tracts by triplex-forming oligonucleotides at physiological pH.
abstract: We have used DNase I footprinting to examine DNA triple helix formation at a 12 base pair oligopurine.oligopyrimidine sequence, using oligonucleotides that contain combinations of 2'-aminoethoxy-5-(3-aminoprop-1-ynyl)uridine (bis-amino-U, BAU) and 3-methyl-2-aminopyridine (MeP) in place of T and C, respectively. This combination acts cooperatively to enable high affinity triple helix formation at physiological pH. The affinity depends on the number of substitutions and their arrangement; oligonucleotides in which these analogues are evenly distributed throughout the third strand bind much better than those in which they are clustered together.
authors.affiliation: School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK.
authors.forename: David A
authors.initials: DA
authors.lastname: Rusling
authors.forename: Loic
authors.initials: L
authors.lastname: Le Strat
authors.forename: Vicki E C
authors.initials: VE
authors.lastname: Powers
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Broughton-Head
authors.forename: James
authors.initials: J
authors.lastname: Booth
authors.forename: Oliver
authors.initials: O
authors.lastname: Lack
authors.forename: Tom
authors.initials: T
authors.lastname: Brown
authors.forename: Keith R
authors.initials: KR
authors.lastname: Fox
mesh_terms: D000631:Aminopyridines; D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D018983:DNA Footprinting; D003850:Deoxyribonuclease I; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D009705:Nucleosides / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry*; D011687:Purines / Q000737:chemistry; D014529:Uridine / Q000031:analogs & derivatives
chemical_list: C488802:2'-aminoethoxy-5-(3-aminoprop-1-ynyl)uridine; D000631:Aminopyridines; D009705:Nucleosides; D009841:Oligonucleotides; D011687:Purines; C051802:triplex DNA; D004247:DNA; D003850:Deoxyribonuclease I; D014529:Uridine