title: Toxic effects of chrysoidine on human serum albumin: isothermal titration calorimetry and spectroscopic investigations.
abstract: Chrysoidine is widely used in industry as a type of azo dye, and is sometimes used illegally as a food additive despite its potential toxicity. Human serum albumin (HSA) is one of the most important proteins in blood plasma and possesses major physiological functions. In the present study, the conformational and functional effects of chrysoidine on HSA were investigated by isothermal titration calorimetry (ITC), multiple spectroscopic methods, a molecular docking study and an esterase activity assay. Based on the ITC results, the binding stoichiometry of chrysoidine to HSA was estimated to be 1.5:1, and was a spontaneous process via a single hydrogen bond. The binding of chrysoidine to HSA induced dynamic quenching in fluorescence, and changes in secondary structure and in the microenvironment of the Trp-214 residue. In addition, the hydrogen bond (1.80 Å) formed between the chrysoidine molecule and the Gln-211 residue. The esterase activity of HSA decreased following the addition chrysoidine due to the change in protein structure. This study details the direct interaction between chrysoidine and HSA at the molecular level and the mechanism for toxicity as a result of the functional changes induced by HSA structural variation upon binding to chrysoidine in vitro. This study provides useful information towards detailing the transportation mechanism and toxicity of chrysoidine in vivo.
authors.affiliation: School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan, 250100, Peoples Republic of China.
authors.forename: Haoyu
authors.initials: H
authors.lastname: Sun
authors.affiliation: School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan, 250100, Peoples Republic of China.
authors.forename: Yingxue
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan, 250100, Peoples Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan, 250100, Peoples Republic of China.
authors.forename: Songlin
authors.initials: S
authors.lastname: Han
authors.affiliation: School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan, 250100, Peoples Republic of China.
authors.forename: Xudan
authors.initials: X
authors.lastname: Yang
authors.affiliation: School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan, 250100, Peoples Republic of China.
authors.forename: Rutao
authors.initials: R
authors.lastname: Liu
mesh_terms: D002151:Calorimetry; D004950:Esterases / Q000737:chemistry / Q000378:metabolism; D005453:Fluorescence; D006801:Humans; D006860:Hydrogen Bonding; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D011487:Protein Conformation / Q000187:drug effects; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D010128:p-Aminoazobenzene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity
chemical_list: D012709:Serum Albumin; C005562:chrysoidine; D010128:p-Aminoazobenzene; D004950:Esterases
keywords: chrysoidine; esterase activity; human serum albumin; isothermal titration calorimetry; spectroscopic investigations