Interaction of DNA with Simple and Mixed Ligand Copper(II) Complexes of 1,10-Phenanthrolines as Studied by DNA-Fiber EPR Spectroscopy
Abstract
:1. Introduction
2. DNA-Fiber EPR Spectra of Cu(II) Complexes
3. Interaction of Cu(II) Complexes of Phen and Its Derivatives with DNA
3.1. 1:1 Complexes of Cu(II) with Phen and Its Methyl Derivatives
- (1).
- It is not clear if mono-phen Cu(II) complex intercalates as [Cu(phen)(H2O)2]2+ after removing the apically coordinated water molecule from [Cu(phen)(H2O)3]2+ or as [Cu(phen)(H2O)4]2+ keeping the two apically coordinated water molecules. At pH 7.0, the presence of [Cu(phen)(H2O)2(OH)]+, [Cu(5,6-dmp)(H2O)2(OH)]+, or [Cu(2,9-dmp)(H2O)2(OH)]+ should also be considered. The positive charge of the complexes decreases by dissociation of a proton from the coordinating water molecule, which does not favor binding to a negatively charged oligo-nucleotide. However, the removal of an apically coordinated water molecule results in the formation of flat coordination plane, which is favorable for intercalative binding.
- (2).
- It would be interesting to investigate whether one of the coordinating water molecules in the complex is substituted with phosphate oxygen or N7 of the guanine residue to produce a covalent interaction.
- (3).
- It is also important to investigate how the binding affinity changes when effecting changes in the base sequence of nucleotides.
3.2. Ternary Complexes with Amino Acids, [Cu(phen)(AA)]n+(n = 1 or 2)
3.3. Cu(II) Complexes of 1,10-Phenanthroline-derived Alkyl Amine
3.4. [Cu(phen)2(H2O)]2+
3.5. Ternary Copper(II)–Phen–Edda Complex [Cu(phen)(edda)]
3.6. Ternary Cu(II) Complexes of Cationic Schiff Bases and N-Heteroaromatic Diimines
Complex | Frozen Solution (−150 °C) | B-Form DNA Fiber (r.t.) * | ||
---|---|---|---|---|
g|| | A||/(10−4 cm−1) | g|| | A||/(10−4 cm−1) | |
1 | 2.26 | 165 | 2.23 | 184 |
2 | 2.26 | 167 | 2.23 | 178 |
3 | 2.26 | 170 | 2.23 | 178 |
3.7. Binary Complex of Cu(II) with 2,2′-Bipyridine (bpy)
4. Conclusions
Supplementary Materials
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Chikira, M.; Ng, C.H.; Palaniandavar, M. Interaction of DNA with Simple and Mixed Ligand Copper(II) Complexes of 1,10-Phenanthrolines as Studied by DNA-Fiber EPR Spectroscopy. Int. J. Mol. Sci. 2015, 16, 22754-22780. https://doi.org/10.3390/ijms160922754
Chikira M, Ng CH, Palaniandavar M. Interaction of DNA with Simple and Mixed Ligand Copper(II) Complexes of 1,10-Phenanthrolines as Studied by DNA-Fiber EPR Spectroscopy. International Journal of Molecular Sciences. 2015; 16(9):22754-22780. https://doi.org/10.3390/ijms160922754
Chicago/Turabian StyleChikira, Makoto, Chew Hee Ng, and Mallayan Palaniandavar. 2015. "Interaction of DNA with Simple and Mixed Ligand Copper(II) Complexes of 1,10-Phenanthrolines as Studied by DNA-Fiber EPR Spectroscopy" International Journal of Molecular Sciences 16, no. 9: 22754-22780. https://doi.org/10.3390/ijms160922754