Molecular binding of toxic phenothiazinium derivatives, azures to bovine serum albumin: A comparative spectroscopic, calorimetric, and in silico study. Issue 7 (19th January 2017)

• Record Type: Journal Article
• Authors: Das, Somnath; Islam, Md. Maidul; Jana, Gopal Chandra; Patra, Anirudha; Jha, Pradeep K.; Hossain, Maidul
• Is Part Of: Journal of molecular recognition. Volume 30:Issue 7(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-01-19
• Subjects: azures -- BSA -- circular dichroism (CD) -- fluorescence spectroscopy -- FTIR -- isothermal titration calorimetry (ITC) -- molecular docking; Molecular recognition -- Periodicals; Models, Molecular -- Periodicals; Molecular Conformation -- Periodicals; Molecular Sequence Data -- Periodicals; Molecular Structure -- Periodicals; Carrier Proteins -- Periodicals; 572.8
• DOI: 10.1002/jmr.2609
• Languages: English
• ISSNs: 0952-3499

Abstract

Abstract: In this paper, the comparative binding behavior of antimalarial drug azure A, azure B and azure C with bovine serum albumin (BSA) has been studied. The interaction has been confirmed by multispectroscopic (UV, fluorescence, Fourier transform infrared (FT‐IR), and circular dichroism) and molecular docking techniques. The experimental results show that azure B has the highest BSA binding affinity followed by azure A and azure C. The experimental evidence of binding showed a static quenching mechanism in the interaction azures with BSA. The isothermal titration calorimetry result reveals that the binding was exothermic with positive entropy contribution in each case. The thermodynamic parameters ΔH, ΔG, and ΔS at 25°C were calculated, which indicates that the weak van der Waals forces and hydrogen bonding rather than the hydrophobic effect played an important role in the interaction. According to the theory of Förster nonradiative energy transfer, the distance (r) between the donor (BSA) and acceptor azures found to be <7 nm in all the case. The circular dichroism and FT‐IR studies show that the content of α‐helix structure has increased for the azures‐BSA system. Overall, experimental studies characterize the interaction dynamics and energetics of the binding of three toxic analogs towards the physiologically relevant serum albumins. We hope, the outcome of this work will be most helpful for synthesizing a new type of phenothiazinium derivatives of the better therapeutic application. Abstract : This work proposes the complete binding study of antimalarial drug azure A, B, and C with BSA/HSA. The interaction has been confirmed by UV‐vis, fluorescence, FT‐IR, and CD spectroscopy with the combination of ITC. The MOE program was also run to describe the interactions site. The binding affinity of azure B was found highest towards BSA followed by azure A and azure C. The thermodynamics of binding was revealed that all the bindings are enthalpy‐driven with a positive entropy.