title: Comparison of interactions between three food colorants and BSA.
abstract: Fast Green FCF (FCF), Patent Blue V (PBV) and Acid Blue 1 (AB1) are used as food colorants. Multiple spectroscopic techniques were employed to probe in depth the affinity of FCF/PBV/AB1 with BSA in different pH and/or salt concentrations. The results showed that FCF/PBV/AB1 quenched the intrinsic fluorescence of BSA by a static process, and electrostatic force dominated the formation of BSA-FCF/PBV/AB1 complex which was confirmed by the effects of salt on their interactions. Subdomain IIA was the primary binding site for FCF/PBV/AB1 on BSA in the pH range of 5.5-7.4, while both Trp 212 and Trp 134 residues of BSA might be bound by FCF/PBV/AB1 at pH 4.8. The K values suggested that the binding ability of three food colorants with BSA was FCF>PBV>AB1. The results of UV-vis absorption, synchronous fluorescence, 3D fluorescence and FT-IR spectra proved that the structure of BSA altered by FCF/PBV/AB1.
authors.affiliation: Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong 637002, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Li
authors.affiliation: Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong 637002, China. Electronic address: ncczj1112@126.com.
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong 637002, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Cao
authors.affiliation: Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong 637002, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Jiang
mesh_terms: D005505:Food Coloring Agents / Q000032:analysis*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D005505:Food Coloring Agents; D012710:Serum Albumin, Bovine
keywords: Acid Blue 1; Binding constant; Bovine serum albumin; Fast Green FCF; Patent Blue V; Spectroscopic techniques