Biomedical and Biotechnology Research Journal (Jan 2022)
DNA binding and cleavage study of novel ruthenium (II)-polypyridine-5-(3-pyridyl)-4H-1,2,4-triazole-3-thiol complex on Escherichia Coli genomic DNA
Abstract
Background: Transition metal complexes especially Ruthenium-Polypyridyl complexes interact with multidentate ligands considered as a new therapeutic agent to make the possible DNA probes and conformers due to several interests owing to their potential applications. The aim of the present work is to concentrate on the binding and cleavage activity of [Ru(bpy)2(pytrzSH)2]2+ (complex 1) and [Ru(phen)2(pytrzSH)2]2+ (complex 2) (bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, pytrzSH = 5-(3-pyridyl)-4H-1,2,4-triazole-3-thiol) on Escherichia coli genomic DNA (gDNA). Materials and Methods: DNA binding and cleavage activity is carried out using ultraviolet-Visible spectral technique and Agarose gel electrophoresis method at three different concentrations against the standard genomic DNA isolated from E. coli bacteria. Results: The changes in the absorbance and wavelength upon incremental addition of the complexes on gDNA clearly depict the binding nature of complexes. The binding constant values for ligand centered and metal to ligand charge transfer transitions obtained from the Benesi Hildebrand plots are found to be 1.560 × 104 and 9.586 × 104 M−1 for complex 1 and 3.594 × 104 and 9.801 × 105 M−1 for complex 2. The results revealed that complex 2 shows better binding property than complex 1 on E. coli gDNA. The extent of DNA cleavage activity of the synthesized complexes on E. coli gDNA is determined from the band intensities, complex 2 shows full cleavage in all the three concentrations, whereas complex 1 exhibits full cleavage at 100 μg/mL. The cleaving ability depends on the nature of the ligands present in the complexes. Conclusion: The synthesized [Ru(bpy)2(pytrzSH)2]2+ (complex 1) and [Ru(phen)2(pytrzSH)2]2+ (complex 2) bind with the E. coli gDNA through electrostatic and intercalative modes. The [Ru(phen)2(pytrzSH)2]2+ complex 2 shows better cleavage activity than [Ru(bpy)2(pytrzSH)2]2+ complex 1.
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