Determining the binding site and binding affinity of estradiol to human serum albumin and holo-transferrin: fluorescence spectroscopic, isothermal titration calorimetry and molecular modeling approaches. Issue 7 (19th May 2018)

• Record Type: Journal Article
• Authors: Danesh, Nazila; Navaee Sedighi, Zahra; Beigoli, Sima; Sharifi-Rad, Atena; Saberi, Mohammad Reza; Chamani, Jamshidkhan
• Is Part Of: Journal of biomolecular structure & dynamics. Volume 36:Issue 7(2018)
• Page Start: 1747
• Page End: 1763
• Publication Date: 2018-05-19
• Subjects: human serum albumin -- human holo transferrin -- estradiol -- three-dimensional fluorescence spectroscopy -- molecular modeling -- isothermal titration calorimetry; Biomolecules -- Periodicals; Molecular structure -- Periodicals; Molecular Biology -- Periodicals; Biomechanics -- Periodicals; 572
• DOI: 10.1080/07391102.2017.1333460
• Languages: English
• ISSNs: 0739-1102

Abstract

Abstract : The interactions between estradiol and two carrier proteins, i.e. human serum albumin (HSA) and holo-transferrin (HTF) in aqueous solution at pH = 7.4 were studied by three-dimensional fluorescence emission spectroscopy, isothermal titration calorimetry (ITC), zeta-potential, resonance light-scattering and molecular modeling. Extensive fluorescence quenching was observed throughout the interaction between the drug and both proteins. Moreover, conformational changes were determined by observing the rearrangement of Trp residues during binding of estradiol with HSA and HTF at different concentrations. ITC experiments revealed that, in the presence of estradiol, both van der Waals forces and hydrogen bonding became predominant. In addition, other binding parameters such as enthalpy and entropy changes were determined by the zeta potential method. Molecular modeling suggested that estradiol was situated within sub-domain IB sited in the hydrophobic cluster in Site I, whereas the drug was located in the N-terminal of HTF where it was hydrogen bonded with Ala 670.