title: Substituent effect on the preferred DNA binding mode and affinity of a homologous series of naphthalene diimides.
abstract: A combination of isothermal titration calorimetry (ITC), topoisomerase I DNA unwinding assays, and ethidium bromide displacement studies were employed to investigate the binding of a homologous series of naphthalene diimides (NDI) to DNA. Our results suggest that the nature of the substituent plays a significant role in both the preferred binding mode and relative binding affinity of the compounds of this study. Only intercalative-type binding (K=15±3×10(6)M(-1)) was observed for the NDI with the smallest substituent (trimethyl-ethylamino), while larger members of the series (diethylmethyl-, dipropylmethyl- and dibutylmethyl-ethylamino substituents) adopted an additional binding mode of higher affinity (K(1)=31-78×10(6)M(-1)).
authors.affiliation: Department of Chemistry, State University of New York at Geneseo, 1 College Circle, Geneseo, NY 14454, USA. mcknight@geneseo.edu
authors.forename: Ruel E
authors.initials: RE
authors.lastname: McKnight
authors.forename: Eric
authors.initials: E
authors.lastname: Reisenauer
authors.forename: Manuel V
authors.initials: MV
authors.lastname: Pintado
authors.forename: Shivani R
authors.initials: SR
authors.lastname: Polasani
authors.forename: Dabney W
authors.initials: DW
authors.lastname: Dixon
mesh_terms: D002151:Calorimetry; D004247:DNA / Q000737:chemistry*; D004264:DNA Topoisomerases, Type I / Q000737:chemistry; D004996:Ethidium / Q000737:chemistry; D007094:Imides / Q000737:chemistry*; D009281:Naphthalenes / Q000737:chemistry*; D011485:Protein Binding
chemical_list: D007094:Imides; D009281:Naphthalenes; C031721:naphthalene; D004247:DNA; D004264:DNA Topoisomerases, Type I; D004996:Ethidium