title: Spectroscopic and molecular simulation studies on the interaction of di-(2-ethylhexyl) phthalate and human serum albumin.
abstract: Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer in industrial production, but may have a potential health risk. In this study, the binding characteristics of DEHP with human serum albumin (HSA) in aqueous solution at pH 7.4 were determined using UV/vis absorption, fluorescence, Fourier transform infrared (FTIR) spectroscopy and circular dichroism (CD), along with a molecular simulation technique. Analysis of the fluorescence titration data at different temperatures suggested that the fluorescence quenching mechanism of HSA by DEHP was static. The calculated thermodynamic parameters indicated that hydrophobic forces played a predominant role in formation of the DEHP-HSA complex, but hydrogen bonds could not be omitted. Site marker competitive experiments and denaturation studies showed that the binding of DEHP to HSA primarily took place in subdomain IIA of HSA, and molecular docking results further corroborated the binding sites. The synchronous fluorescence, UV/vis absorption, FTIR and CD spectra revealed that the addition of DEHP induced changes in the secondary structure of HSA. Protein surface hydrophobicity (PSH) tests indicated that DEHP binding to HSA caused an increase in the PSH. Moreover, the effects of some metal ions on the binding constant of DEHP - HSA interaction were also investigated.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Wang
authors.forename: Guowen
authors.initials: G
authors.lastname: Zhang
mesh_terms: D002942:Circular Dichroism; D004051:Diethylhexyl Phthalate / Q000737:chemistry*; D006801:Humans; D062105:Molecular Docking Simulation; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D012709:Serum Albumin; D004051:Diethylhexyl Phthalate
keywords: binding characteristic; di-(2-ethylhexyl) phthalate; fluorescence quenching; human serum albumin; molecular docking