title: Synthesis and DNA binding/cleavage of mononuclear copper(II) phenanthroline/bipyridine proline complexes.
abstract: The complexes [Cu(II)(phen)(L-Pro)(H2O)]+ ClO4(-) (1; phen = 1,10-phenanthroline) and [Cu(II)(bipy)(L-Pro)(H2O)]+ ClO4(-) (2; bipy = 2,2'-bipyridine) were synthesized and characterized by IR, magnetic susceptibility, UV/VIS, EPR, ESI-MS, elemental analysis, and theoretical calculations. The metal center was found in a square-pyramidal geometry. UV/VIS, thermal-denaturation, and fluorescence-spectroscopic studies were conducted to assess the interaction of the complexes with CT-DNA. An intercalative mode of binding was found, with intrinsic binding constants (Kb) of 3.86x10(3) and 4.6x10(3) M(-1) and Stern-Volmer quenching constants (K) of 0.15 and 0.11 for 1 and 2, respectively. Interestingly, none of the Cu(II) complexes was able to cleave pUC-19 DNA, which is attributed to the absence of a Pro amide H-atom and inhibition of the formation of an OH radical from the axially coordinated H2O molecule.
authors.affiliation: Department of Chemistry, Osmania University, Hyderabad, India. rabi_pr@rediffmail.com
authors.forename: Pulimamidi R
authors.initials: PR
authors.lastname: Reddy
authors.forename: Nomula
authors.initials: N
authors.lastname: Raju
authors.forename: Pallerla
authors.initials: P
authors.lastname: Manjula
authors.forename: Karnati V G
authors.initials: KV
authors.lastname: Reddy
mesh_terms: D004247:DNA / Q000378:metabolism*; D053837:DNA Cleavage; D010618:Phenanthrolines / Q000138:chemical synthesis / Q000378:metabolism*; D011392:Proline / Q000138:chemical synthesis / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D011725:Pyridines / Q000138:chemical synthesis / Q000378:metabolism*
chemical_list: D010618:Phenanthrolines; D011725:Pyridines; D004247:DNA; D011392:Proline; C023666:pyridine; C025205:1,10-phenanthroline