title: Properties of triple helices formed by parallel-stranded hairpins containing 8-aminopurines.
abstract: Parallel-stranded hairpins with a polypyrimidine sequence linked to a complementary purine carrying 8-aminopurines such as 8-aminoadenine, 8-aminoguanine and 8-aminohypoxanthine bind polypyrimidine sequences complementary (in an antiparallel sense) to the purine part by a triple helix. The relative stabilities of triplexes were assessed by UV-absorption melting experiments as a function of pH and salt concentration. Hairpins carrying 8-aminopurines give very stable triple helical structures even at neutral pH, as confirmed by gel-shift experiments, circular dichroism and nuclear magnetic resonance spectroscopy. The modified hairpins may be redesigned to cope with small interruptions in the polypyrimidine target sequence.
authors.affiliation: Cygene Spain S.L., Parc Científic de Barcelona, Baldiri i Reixac 10-12, E-08028 Barcelona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Aviñó
authors.forename: Miriam
authors.initials: M
authors.lastname: Frieden
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Morales
authors.forename: Beatriz
authors.initials: B
authors.lastname: García de la Torre
authors.forename: Ramón
authors.initials: R
authors.lastname: Güimil García
authors.forename: Ferran
authors.initials: F
authors.lastname: Azorín
authors.forename: José Luis
authors.initials: JL
authors.lastname: Gelpí
authors.forename: Modesto
authors.initials: M
authors.lastname: Orozco
authors.forename: Carlos
authors.initials: C
authors.lastname: González
authors.forename: Ramon
authors.initials: R
authors.lastname: Eritja
mesh_terms: D000588:Amines / Q000737:chemistry; D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D006147:Guanine / Q000031:analogs & derivatives* / Q000737:chemistry; D006358:Hot Temperature; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009841:Oligonucleotides / Q000737:chemistry; D011687:Purines / Q000737:chemistry*; D011743:Pyrimidines / Q000378:metabolism; D012492:Salts / Q000494:pharmacology
chemical_list: D000588:Amines; D009841:Oligonucleotides; D011687:Purines; D011743:Pyrimidines; D012492:Salts; C051802:triplex DNA; C033495:8-aminoguanine; D006147:Guanine; D004247:DNA