title: Synthesis, DNA recognition and cleavage studies of novel tetrapeptide complexes, Cu(II)/Zn(II)-Ala-Pro-Ala-Pro.
abstract: New tetrapeptide complexes Cu(II)·Ala-Pro-Ala-Pro (1) and Zn(II)·Ala-Pro-Ala-Pro (2) were synthesized from the reaction of tetrapeptide, Ala-Pro-Ala-Pro and CuCl2/ZnCl2 and were thoroughly characterized by elemental analysis, IR,(1)H and (13)C NMR (in case of 2), ESI-MS, UV and molar conductance measurements. The solution stability study was carried out employing UV-vis absorption titrations over a broad range of pH which suggested the stability of the complexes in solution. In vitro interaction of complexes 1 and 2 with CT-DNA was studied employing UV-vis, fluorescence, circular dichroic and viscometry studies. To throw insight into molecular binding event at the target site, UV-vis titrations of 1 and 2 with mononucleotides of interest viz.; 5'-GMP and 5'-TMP were carried out. Cleavage activity of the complexes with pBR322 plasmid DNA was evaluated by agarose gel electrophoresis and, the electrophoresis pattern demonstrated that both the complexes 1 and 2 are efficient cleavage agents. Further, the Cu(II) complex displayed efficient oxidative cleavage of supercoiled DNA while various reactive oxygen species are responsible for the cleavage in Zn(II) complex.
authors.affiliation: Department of Chemistry, Aligarh Muslim University, Aligarh 202 002, Uttar Pradesh, India. farukh_arjmand@yahoo.co.in
authors.forename: Farukh
authors.initials: F
authors.lastname: Arjmand
authors.forename: A
authors.initials: A
authors.lastname: Jamsheera
authors.forename: D K
authors.initials: DK
authors.lastname: Mohapatra
mesh_terms: D000042:Absorption; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D053837:DNA Cleavage; D004578:Electron Spin Resonance Spectroscopy; D004583:Electrons; D004587:Electrophoresis, Agar Gel; D007700:Kinetics; D049449:Luminescence; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D055550:Protein Stability; D012996:Solutions; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D014783:Viscosity; D015032:Zinc / Q000378:metabolism*
chemical_list: D056831:Coordination Complexes; C583706:Cu(II)-Ala-Pro-Ala-Pro; D009842:Oligopeptides; D012996:Solutions; D003300:Copper; D004247:DNA; C427203:calf thymus DNA; D015032:Zinc