title: In vitro DNA binding studies of the sweetening agent saccharin and its copper(II) and zinc(II) complexes.
abstract: The interactions of fish sperm DNA (FS-DNA) with the sodium salt of sweetener saccharin (sacH) and its copper and zinc complexes, namely [M(sac)2(H2O)4]·2H2O (M=Cu(II) or Zn(II)) were studied by using UV-Vis titration, fluorometric competition, thermal denaturation, viscosity and gel electrophoresis measurements. The intrinsic binding constants (Kb) obtained from absorption titrations were estimated to be 2.86 (±0.06)×10(4)M(-1) for Na(sac), 6.67 (±0.12)×10(4)M(-1) for Cu-sac and 4.01 (±0.08)×10(4)M(-1) for Zn-sac. The Cu-sac complex binds to FS-DNA via intercalation with a KA value of 50.12 (±0.22)×10(4)M(-1) as evidenced by competitive binding studies with ethidium bromide. Moreover, competition experiments with Hoechst 33258 are indicative of a groove binding mode of Na(sac) and Zn-sac with binding constants of 3.13 (±0.16)×10(4)M(-1) and 5.25 (±0.22)×10(4)M(-1), respectively. The spectroscopic measurements indicate a moderate DNA binding affinity of Na(sac) and its metal complexes. The suggested binding modes are further confirmed by the thermal denaturation and viscosity measurements. In addition, Cu-sac and Zn-sac show weak ability to damage to pBR322 supercoiled plasmid DNA.
authors: Department of Chemistry, Faculty of Arts and Sciences, Uludag University, 16059 Bursa, Turkey.
authors: Ceyda
authors: C
authors: Icsel
authors: Department of Chemistry, Faculty of Arts and Sciences, Uludag University, 16059 Bursa, Turkey. Electronic address: vtyilmaz@uludag.edu.tr.
authors: Veysel T
authors: VT
authors: Yilmaz
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D053837:DNA Cleavage; D012439:Saccharin / Q000737:chemistry / Q000494:pharmacology*; D013549:Sweetening Agents / Q000737:chemistry / Q000494:pharmacology*; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D056831:Coordination Complexes; D013549:Sweetening Agents; D003300:Copper; D004247:DNA; D012439:Saccharin; D015032:Zinc
keywords: Copper(II) saccharinate; DNA binding; Fluorescence spectroscopy; Saccharin; UV–Vis spectroscopy; Zinc(II) saccharinate