title: Interaction between alizarin and human serum albumin by fluorescence spectroscopy.
abstract: The binding properties on alizarin to human serum albumin (HSA) have been studied for the first time using fluorescence spectroscopy in combination with UV-visible absorbance spectroscopy. The results showed that alizarin strongly quenched the intrinsic fluorescence of HSA through a static quenching procedure, and non-radiation energy transfer occurred within the molecules. The number of binding sites was 1, and the efficiency of Förster energy transfer provided a distance of 1.83 nm between tryptophan and alizarin binding site. ΔH(θ), ΔS(θ) and ΔG(θ) were obtained based on the quenching constants and thermodynamic theory (ΔH(θ) < 0, ΔS(θ) > 0 and ΔG(θ) < 0). These results indicated that hydrophobic and electrostatic interactions are the main binding forces in the alizarin-HSA system. In addition, the results obtained from synchronous fluorescence spectra and three-dimensional fluorescence spectra showed that the binding of alizarin with HSA could induce conformational changes in HSA.
authors.affiliation: School of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650224, P. R. China. gefeng79@yahoo.com.cn
authors.forename: Feng
authors.initials: F
authors.lastname: Ge
authors.forename: Lixiang
authors.initials: L
authors.lastname: Jiang
authors.forename: Diqiu
authors.initials: D
authors.lastname: Liu
authors.forename: Chaoyin
authors.initials: C
authors.lastname: Chen
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D006801:Humans; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
chemical_list: D000880:Anthraquinones; D012709:Serum Albumin; C010078:alizarin