title: Interdependence of pyrene interactions and tetramolecular G4-DNA assembly.
abstract: Controlling the arrangement of organic chromophores in supramolecular architectures is of primary importance for the development of novel functional molecules. Insertion of a twisted intercalating nucleic acid (TINA) moiety, containing phenylethynylpyren-1-yl derivatives, into a G-rich DNA sequence alters G-quadruplex folding, resulting in supramolecular structures with defined pyrene arrangements. Based on CD, NMR and ESI-mass-spectra, as well as TINA excited dimer (excimer) fluorescence emission we propose that insertion of the TINA monomer in the middle of a dTG4T sequence (i.e. dTGGXGGT, where X is TINA) converts a parallel tetramolecular G-quadruplex into an assembly composed of two identical antiparallel G-quadruplex subunits stacked via TINA-TINA interface. Kinetic analysis showed that TINA-TINA association controls complex formation in the presence of Na(+) but barely competes with guanine-mediated association in K(+) or in the sequence with the longer G-run (dTGGGXGGGT). These results demonstrate new perspectives in the design of molecular entities that can kinetically control G-quadruplex formation and show how tetramolecular G-quadruplexes can be used as a tuneable scaffold to control the arrangement of organic chromophores.
authors: College of Sciences, Institute of Fundamental Sciences, Massey University, Private Bag 11-222, 4442 Palmerston North, New Zealand. v.filichev@massey.ac.nz.
authors: Osman
authors: O
authors: Doluca
authors: Jamie M
authors: JM
authors: Withers
authors: Trevor S
authors: TS
authors: Loo
authors: Patrick J B
authors: PJ
authors: Edwards
authors: Carlos
authors: C
authors: González
authors: Vyacheslav V
authors: VV
authors: Filichev
mesh_terms: D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D054856:G-Quadruplexes; D006860:Hydrogen Bonding; D007364:Intercalating Agents / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011721:Pyrenes / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D007364:Intercalating Agents; D011721:Pyrenes; D004247:DNA; C030984:pyrene