title: Study of the interaction between mercury (II) and bovine serum albumin by spectroscopic methods.
abstract: Mercury is a significant environmental pollutant that originates from industry. Mercury will bind with albumin and destroy biological functions in humans if it enters the blood. In this paper, the interaction between mercury (II) and bovine serum albumin (BSA) was investigated in vitro by fluorescence, UV-Vis absorption and circular dichroism (CD) under simulated physiological conditions. This study proves that the probable quenching mechanism of BSA by mercury (II) was mainly static quenching due to the formation of a mercury (II)-BSA complex. The quenching constant K(a) and the corresponding thermodynamic parameters (ΔH, ΔS and ΔG) at four different temperatures were calculated by a modified Stern-Volmer equation and the van't Hoff equation, respectively. The results revealed that the interaction between mercury (II) and BSA was mainly enthalpy-driven and that hydrogen bonding and van der Waals forces played a major role in the reaction. The obtained data for binding sites of n approximately equal to 1 indicated that there was a single class of binding site for the BSA with mercury (II). The value of the distance r (3.55 nm), determined by Föster's non-radioactive energy transfer theory, suggested that the energy transfer from BSA to mercury (II) occurred with a high probability. The conformational investigation from synchronous fluorescence, CD spectroscopy and three-dimensional fluorescence showed that the presence of mercury (II) resulted in micro-environmental and conformational changes of the BSA molecules, which may be responsible for the toxicity of mercury (II) in vivo.
authors.affiliation: Liaoning Medical University, Jinzhou 121001, PR China.
authors.forename: Dai
authors.initials: D
authors.lastname: Chunmei
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating) School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors.forename: Ji
authors.initials: J
authors.lastname: Cunwei
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating) School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.
authors.forename: Lan
authors.initials: L
authors.lastname: Huixiang
authors.affiliation: Liaoning Medical University, Jinzhou 121001, PR China.
authors.forename: Song
authors.initials: S
authors.lastname: Yuze
authors.affiliation: Liaoning Medical University, Jinzhou 121001, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating) School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China. Electronic address: zhengdan@mails.tjmu.edu.cn.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Dan
mesh_terms: D001665:Binding Sites; D002942:Circular Dichroism; D004785:Environmental Pollutants / Q000378:metabolism*; D008628:Mercury / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
chemical_list: D004785:Environmental Pollutants; D012710:Serum Albumin, Bovine; D008628:Mercury
keywords: Bovine serum albumin (BSA); Circular dichroism (CD); Fluorescence spectroscopy; Mercury; Thermodynamic parameter; Three-dimensional fluorescence spectra