1030620-00-8Relevant articles and documents
DNA binding by a new metallointercalator that contains a proflavine group bearing a hanging chelating unit
Bazzicalupi, Carla,Bencini, Andrea,Bianchi, Antonio,Biver, Tarita,Boggioni, Alessia,Bonacchi, Sara,Danesi, Andrea,Giorgi, Claudia,Gratteri, Paola,Ingrain, Antonio Marchal,Secco, Fernando,Sissi, Claudia,Valtancoli, Barbara,Venturini, Marcella
, p. 184 - 196 (2008/09/18)
The new bifunctional molecule 3,6-diamine-9-[6,6-bis(2-amino-elhyl)-1,6- diaminohexyl]acridine (D), which is characterised by both an aromatic moiety and a separate metal-complexing polyamine centre, has been synthesised. The characteristics of D and its Zn11 complex ([ZnD]) (protonation and metal-complexing constants, optical properties and self-aggregation phenomena) have been analysed by means of NMR spectroscopy, Potentiometric, spectrophotometric and spectrofluorimetric techniques. The equilibria and kinetics of the binding process of D and [ZnD] to calf thymus DNA have been investigated at I =0.11 M (NaCl) and 298.1 K by using spectroscopic methods and the stopped-flow technique. Static measurements show biphasic behaviour for both D-DNA and [ZnD]-DNA systems; this reveals the occurrence of two different binding processes depending on the polymer-to-dye molar ratio (P/D). The binding mode that occurs at low P/D values is interpreted in terms of external binding with a notable contribution from the polyamine residue. The binding mode at high P/D values corresponds to intercalation of the proflavine residue. Stopped-flow, circular dichroism and supercoiled-DNA unwinding experiments corroborate the proposed mechanism. Molecular-modelling studies support the intercalative process and evidence the influence of NH+...O interactions between the protonated acridine nitrogen atom and the oxygen atoms of the polyanion; these interactions play a key role in determining the conformation of DNA adducts.
