DNA binding ability and hydrogen peroxide induced nuclease activity of a novel Cu(II) complex with malonate as the primary ligand and protonated 2-amino-4-picoline as the counterion.
The DNA binding property of a Cu(II) complex, viz., [Cu(mal)(2)](picH)(2).2H(2)O, (mal)(2) = malonic acid, picH = protonated 2-amino-4-picoline, has been investigated in this study. The binding of this complex with plasmid and chromosomal DNA has been characterized by different biophysical techniques. From the absorption and fluorescence spectroscopic studies, it has been observed that the said copper complex binds strongly with pUC19 plasmid and CT DNA with a binding affinity of 2.368 x 10(3) and 4.0 x 10(3) M(-1), respectively, in 10 mM citrate-phosphate buffer, pH 7.4. Spectrofluorimetric studies reveal that the copper complex exhibits partial DNA intercalation as well as partial DNA minor groove binding properties. Consequently, in agarose gel electrophoresis study, it has been observed that the complex alone induces positive supercoiling in plasmid DNA while in the presence of H(2)O(2) it exhibits nuclease activity. The induction of the breakage in DNA backbone depends upon the relative concentrations of H(2)O(2) and copper complex followed by the time of incubation with DNA. Optical DNA melting study, isothermal titration calorimetry, and absorption spectroscopy have been used to characterize the nuclease activity of this complex in the presence of H(2)O(2). Further, (1)H NMR study indicates that Cu(II) in the complex is converted into the Cu(I) state by the reduction of H(2)O(2). Finally, agarose gel electrophoresis study with different radical scavengers concludes that the production of both hydroxyl radicals and reactive oxygen species is responsible for this nuclease activity.
Saha
Biswarup
B
Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S.C. Mullick Road, Kolkata 700 032, West Bengal, India.
Islam
Md Maidul
MM
Paul
Susmita
S
Samanta
Saheli
S
Ray
Shayoni
S
Santra
Chitta Ranjan
CR
Ray Choudhury
Somnath
S
Dey
Biswajit
B
Das
Amrita
A
Ghosh
Somnath
S
Mukhopadhyay
Subrata
S
Kumar
Gopinatha Suresh
GS
Karmakar
Parimal
P
D002942:Circular Dichroism; D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D003851:Deoxyribonucleases / Q000737:chemistry / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008024:Ligands; D008314:Malonates / Q000737:chemistry; D008968:Molecular Conformation; D010847:Picolines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D056831:Coordination Complexes; D008024:Ligands; D008314:Malonates; D010847:Picolines; C015672:2-amino-4-picoline; D003300:Copper; D004247:DNA; D006861:Hydrogen Peroxide; D003851:Deoxyribonucleases