title: DNA cleavage induced by [Cu(L)x(NO3)2] (L=2,2'-dipyridylamine, 2,2'-bipyridine, dipicolylamine, x=1 or 2): Effect of the ligand structure.
abstract: The efficiency of [Cu(2,2'-bipyridine)2(NO3)]NO3, [Cu(2,2'-dipyridylamine)2(NO3)2], and [Cu(dipicolylamine)2(NO3)2] complexes (complex 1, 2 and 3, respectively) in oxidative DNA cleavage was examined by electrophoresis and linear dichroism (LD). Among the three Cu complexes, complex 1 showed the highest efficiency in super-coiled DNA (scDNA) cleavage in electrophoresis. The presence of tiron, a superoxide radical scavenger, suppressed the reaction almost completely. The LD signal at 260 nm decreased gradually as the time passed. The decrease in LD magnitude was explained best by the sum of the two single exponential curves. This suggests that the cleavage reaction involves two first order kinetic processes; an increase in flexibility due to scission of one of the strands and a shortening in the DNA stem due to cut of both strands of double stranded DNA (dsDNA). In agreement with the electrophoresis data, complex 1 exhibited the highest efficiency with the superoxide radical found to be the essential reactive oxygen species. The order of efficiency in both scDNA and dsDNA was as follows: complex 1>complex 2>complex 3. The electrochemical properties alone were insufficient to explain the observed efficiencies, even though reduction of the central Cu ion is essential for the oxidative DNA cleavage. This highlights the importance of an ability to ligate the molecular oxygen (or hydrogen peroxide) to the central Cu ion to produce the superoxide radical, in addition to the reduction of Cu ion, in oxidative DNA cleavage.
authors.affiliation: Department of Chemistry, Yeungnam University, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Kwon
authors.affiliation: Department of Chemistry, Yeungnam University, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea.
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Department of Chemistry, Yeungnam University, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea.
authors.forename: Nataraj
authors.initials: N
authors.lastname: Chitrapriya
authors.affiliation: Department of Chemistry, Yeungnam University, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea.
authors.forename: Tae-Sub
authors.initials: TS
authors.lastname: Cho
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Republic of Korea.
authors.forename: Soojin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Republic of Korea.
authors.forename: Jinheung
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science & Technology, Seoul 139-743, Republic of Korea.
authors.forename: In Hong
authors.initials: IH
authors.lastname: Hwang
authors.affiliation: Department of Fine Chemistry, Seoul National University of Science & Technology, Seoul 139-743, Republic of Korea. Electronic address: chealkim@seoultech.ac.kr.
authors.forename: Cheal
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Yeungnam University, Gyeongsan City, Gyeong-buk, 712-749, Republic of Korea. Electronic address: seogkim@yu.ac.kr.
authors.forename: Seog K
authors.initials: SK
authors.lastname: Kim
mesh_terms: D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D055664:Electrochemical Techniques; D008024:Ligands; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods; D013329:Structure-Activity Relationship
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D017382:Reactive Oxygen Species; D003300:Copper; D004247:DNA
keywords: Cu complex; DNA; DNA cleavage; Linear dichroism; Oxidation