title: Studying the influence of the pyrene intercalator TINA on the stability of DNA i-motifs.
abstract: Certain cytosine-rich (C-rich) DNA sequences can fold into secondary structures as four-stranded i-motifs with hemiprotonated base pairs. Here we synthesized C-rich TINA-intercalating oligonucleotides by inserting a nonnucleotide pyrene moiety between two C-rich regions. The stability of their i-motif structures was studied by using UV melting temperature measurements and circular dichroism spectra at different pH values under noncrowding and crowding conditions (20% poly(ethylene glycol)). When TINA ((R)-3-((4-(1-pyrenylethynyl)benzyl)oxy) propane-1,2-diol) is inserted, the oligonucleotides could form an i-motif at a higher pH than observed for the corresponding wildtype oligonucleotide.
authors.affiliation: Nucleic Acid Center, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: El-Sayed
authors.forename: Erik B
authors.initials: EB
authors.lastname: Pedersen
authors.forename: Nahid A
authors.initials: NA
authors.lastname: Khaireldin
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008968:Molecular Conformation; D011092:Polyethylene Glycols / Q000737:chemistry; D011409:Propylene Glycols / Q000737:chemistry*; D011721:Pyrenes / Q000737:chemistry*; D044366:Transition Temperature; D014466:Ultraviolet Rays
chemical_list: D011409:Propylene Glycols; D011721:Pyrenes; D011092:Polyethylene Glycols; D004247:DNA; C030984:pyrene