DNA Binding with Acetate Bis(1,10-phenanthroline)silver(I) Monohydrate in a Solution and Metallization of Formed Structures

Abstract

Abstract:The study of DNA interaction with the acetate bis(1,10-phenanthroline)silver(I) monohydrate in a solution is of interest both for understanding the mechanism of biological activity of silver compound and for forming ordered structures (DNA fibrils) that can be used to solve various problems in the field of nanotechnology. The analysis of changing the DNA conformation (secondary structure, persistent length and volume effects) during the interaction by the methods of UV spectroscopy with the analysis of DNA melting, circular dichroism, viscosity, flow birefringence, AFM (atomic force microscopy) and SEM (scanning electron microscopy) was performed. The formation of two types of complexes was observed. At lower concentration of compound in DNA solution, silver atoms form the coordination bonds with a macromolecule, while the released phenanthroline ligands intercalate between DNA bases. When the concentration of the compound increases, the phenanthroline ligands form an ordered "layer" around the helix. The excess of silver compounds in the DNA solution (with more than five silver atoms per base pair), DNA precipitation is observed with the formation of long fibrils. It was shown that the binding of silver to DNA during the formation of complexes provides further metallization of the resulting structures with the aid of reducing agents; phenanthroline ligands influence the result of such metallization.

Bottom-Up Fabrication of DNA-Templated Electronic Nanomaterials and Their Characterization

“…Different procedures have been utilized to incorporate metal ions, such as silver, into DNA strands to construct metal nanostructures. Kasyanenko et al [ 76 ] bound bis(1,10-phenanthroline) silver(I) (Ag-Phen) to DNA in solution where the phenanthroline ligands allowed for uniform binding of silver on DNA structures. The Ag-Phen-DNA complexes were treated with sodium borohydride to reduce Ag metal on DNA fibrils.…”

Synthesis and Spectroscopic Investigations of Schiff Base Ligand and Its Bimetallic Ag(I) Complex as DNA and BSA Binders

“…Covalent bonding involves the exchange of a labile ligand that is part of a coordination compound for one of the DNA bases [29] in which the N7 atoms of adenine and guanine are preferred [30] which affects the electron density of the heterocycles, causing instability of the DNA helix. The large number of binding sites disrupt the hydrogen bonding and stacking of nitrogenous bases [31]. Silver complexes can also bind to DNA through electrostatic binding to the phosphate backbone or binding in a major or minor groove of helix [32][33][34][35].…”

<p>Synthesis, Characterization and DNA Binding Investigations of a New Binuclear Ag(I) Complex and Evaluation of Its Anticancer Property</p>

“…[12][13][14] The presence of the ligands in the silver complexes leads to the improvement of the silver function. 15 Moreover, the high number of Ag(I) center ions in a complex can improve the biological activity of silver complexes, 16 and the cytotoxic effect of binuclear silver(I) complexes is significantly more in cancer cells in comparison with the normal cells. 14 Haque et al showed that silver ions have a fundamental importance in the destruction of tumor cells.…”

“…3,12 Anticancer agents mostly act through the DNA molecule. 15 Molecules may interact with DNA by changing or preventing its operation, disordering gene sequencesand introde in transcription. 17 The main binding types in DNA complexes are covalent and non-covalent.…”

“…This is important in the development of biotechnological areas and also the ligands of the complexes can intercalate between bases of DNA. DNA may be metalized by the coordination of silver to bases of DNA 15 or with the aid of electrostatic binding. 24,25 This report describes the synthesis and characterization of a new binuclear Ag complex,…”