Interaction of human serum albumin with Fe(III)–deferasirox studied by multispectroscopic methods

• Published in: Journal of luminescence 2014-05, Vol.149, p.251-257
• Main Authors: Dehghan, Gholamreza, Shaghaghi, Masoomeh, Sattari, Safura, Jouyban, Abolghasem
• Format: Article
• Language: English
• Subjects: Binding; Binding sites; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Constants; Cross-disciplinary physics: materials science; rheology; Dichroism; Entropy; Exact sciences and technology; Fe(III)–deferasirox complex; Fluorescence; Fluorescence quenching; Human serum albumin; Hydrophobic interaction; Materials science; Mathematical analysis; Multispectroscopic methods; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Photoluminescence; Physics; Serum albumin; Thermal properties of condensed matter; Thermal properties of crystalline solids; Thermodynamic properties; Treatment of materials and its effects on microstructure and properties
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2014.01.047

The interaction between the iron complex of deferasirox (Fe(III)–DFX) and human serum albumin (HSA) was studied by fluorescence, UV–vis absorption and circular dichroism (CD) spectroscopy. Binding constants, number of binding sites and binding distance (r) were calculated. Fluorescence data at different temperatures revealed that the fluorescence intensity of HSA is decreased in the presence of Fe(III)–DFX complex, and the fluorescence quenching was the result of the formation of the Fe(III)–DFX–HSA complex, therefore the quenching mechanism was static. The binding constant (Ka) for the interaction was 104, and the number of binding site was obtained ~1. The thermodynamic parameters including enthalpy (∆H), entropy (∆S) and Gibb׳s free energy (∆G) changes were calculated according to the van׳t Hoff equation. These data suggested that hydrophobic interaction was the dominant intermolecular force in stabilizing the complex and the association process was spontaneous. The interaction of HSA with Fe(III)–DFX was also confirmed by UV–vis absorption spectra. The quantitative analysis data of CD spectra showed significant alterations of HSA secondary structure in the presence of Fe(III)–DFX complex in aqueous solution with reduction of α-helices content and increase of β-turn structure. •The interaction between Fe(III)–DFX and (HSA) was studied by multispectroscopic methods.•Fluorescence intensity of HSA is decreased in the presence of Fe(III)–DFX complex through a static quenching procedure.•Thermodynamic data suggested that hydrophobic interaction was the dominant intermolecular force and the association process was spontaneous.•The CD spectra showed significant alterations of HSA secondary structure with reduction of α-helices content and increase of β-turn structure.