title: Binding affinities of Schiff base Fe(II) complex with BSA and calf-thymus DNA: Spectroscopic investigations and molecular docking analysis.
abstract: The binding interaction of a synthesized Schiff base Fe(II) complex with biological macromolecules viz., bovine serum albumin (BSA) and calf thymus(ct)-DNA have been investigated using different spectroscopic techniques coupled with viscosity measurements at physiological pH and 298K. Regular amendments in emission intensities of BSA upon the action of the complex indicate significant interaction between them, and the binding interaction have been characterized by Stern Volmer plots and thermodynamic binding parameters. On the basis of this quenching technique one binding site with binding constant (Kb=(7.6±0.21)×10(5)) between complex and protein have been obtained at 298K. Time-resolved fluorescence studies have also been encountered to understand the mechanism of quenching induced by the complex. Binding affinities of the complex to the fluorophores of BSA namely tryptophan (Trp) and tyrosine (Tyr) have been judged by synchronous fluorescence studies. Secondary structural changes of BSA rooted by the complex has been revealed by CD spectra. On the other hand, hypochromicity of absorption spectra of the complex with the addition of ct-DNA and the gradual reduction in emission intensities of ethidium bromide bound ct-DNA in presence of the complex indicate noticeable interaction between ct-DNA and the complex with the binding constant (4.2±0.11)×10(6)M(-1). Life-time measurements have been studied to determine the relative amplitude of binding of the complex to ct-DNA base pairs. Mode of binding interaction of the complex with ct-DNA has been deciphered by viscosity measurements. CD spectra have also been used to understand the changes in ct-DNA structure upon binding with the metal complex. Density functional theory (DFT) and molecular docking analysis have been employed in highlighting the interactive phenomenon and binding location of the complex with the macromolecules.
authors.affiliation: Department of Chemistry, Jadavpur University, Kolkata 700 032, India.
authors.forename: Suparna
authors.initials: S
authors.lastname: Rudra
authors.affiliation: Department of Chemistry, Jadavpur University, Kolkata 700 032, India.
authors.forename: Somnath
authors.initials: S
authors.lastname: Dasmandal
authors.affiliation: Department of Chemistry, Jadavpur University, Kolkata 700 032, India.
authors.forename: Chiranjit
authors.initials: C
authors.lastname: Patra
authors.affiliation: Department of Chemistry, Jadavpur University, Kolkata 700 032, India.
authors.forename: Arjama
authors.initials: A
authors.lastname: Kundu
authors.affiliation: Department of Chemistry, Jadavpur University, Kolkata 700 032, India.
authors.forename: Ambikesh
authors.initials: A
authors.lastname: Mahapatra
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D005296:Ferrous Compounds / Q000737:chemistry / Q000378:metabolism*; D062105:Molecular Docking Simulation; D011485:Protein Binding; D017433:Protein Structure, Secondary / Q000187:drug effects; D012545:Schiff Bases / Q000737:chemistry / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D005296:Ferrous Compounds; D012545:Schiff Bases; D012710:Serum Albumin, Bovine; D004247:DNA; C427203:calf thymus DNA
keywords: Fe(II) complex; Schiff base; Serum albumin; ct-DNA