title: Binding of DNA by a dinitro-diester calix[4]arene: denaturation and condensation of DNA.
abstract: A study of a dinitro-diester calix[4]arene (5,17-(3-nitrobenzylideneamino)-11,23-di-tert-butyl-25,27-diethoxycarbonyl methyleneoxy-26,28-dihydroxycalix[4]arene) interaction with calf-thymus DNA was carried out using several techniques. The measurements were done at various molar ratios X=[calixarene]/[DNA]. Results show diverse changes in the DNA conformation depending on the X value. Thus, at low macrocycle concentrations, the calixarene binds to the polynucleotide. This interaction, mainly in groove mode, weakens the hydrogen bonds between base pairs of the helix inducing denaturation of the double strands, as well as condensation of the macromolecule, from an extended coil state to a globular state. An opposite effect is observed at X molar ratios higher than 0.07. The de-condensation of DNA happens, that is, the transition from a compact state to a more extended conformation, probably due to the stacking of calixarene molecules in the solution. Results also show the importance of making a proper choice of the system under consideration.
authors: Department of Physical Chemistry, Faculty of Chemistry, University of Seville, c/ Prof. García González n° 1, Sevilla 41012, Spain.
authors: F J
authors: FJ
authors: Ostos
authors: Department of Physical Chemistry, Faculty of Chemistry, University of Seville, c/ Prof. García González n° 1, Sevilla 41012, Spain.
authors: J A
authors: JA
authors: Lebron
authors: Department of Physical Chemistry, Faculty of Chemistry, University of Seville, c/ Prof. García González n° 1, Sevilla 41012, Spain.
authors: M L
authors: ML
authors: Moyá
authors: Department of Science, Institute of Technology Tallaght (ITT Dublin), Dublin 24, Ireland.
authors: M
authors: M
authors: Deasy
authors: Department of Physical Chemistry, Faculty of Chemistry, University of Seville, c/ Prof. García González n° 1, Sevilla 41012, Spain. Electronic address: pcornejo@us.es.
authors: P
authors: P
authors: López-Cornejo
mesh_terms: D000818:Animals; D047250:Calixarenes / Q000378:metabolism*; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism*; D004996:Ethidium / Q000737:chemistry; D018625:Microscopy, Atomic Force; D009691:Nucleic Acid Denaturation; D013050:Spectrometry, Fluorescence; D014783:Viscosity
chemical_list: D047250:Calixarenes; D004247:DNA; C427203:calf thymus DNA; D004996:Ethidium
keywords: Calixarene; Condensation; DNA; Denaturation; Gene therapy; Non-covalent interactions