title: Molecular spectroscopic studies on the interaction of morin with bovine serum albumin.
abstract: The interaction between morin and bovine serum albumin (BSA) was studied using molecular spectroscopic approach at different temperatures under imitated physiological conditions. Quenching of intrinsic tryptophanyl fluorescence of BSA with increasing morin concentration is the actuating tool in the analysis. The obtained quenching mechanisms, binding constants, binding sites and corresponding thermodynamic parameters at different temperatures indicate that the hydrophobic interaction play a major role in the morin-BSA association. Binding affinity between morin and BSA was determined using Scatchard equation and the modified Stern-Volmer equation, and the corresponding Structure-affinity relationships of flavonoids were discussed. Site marker competitive displacement experiments demonstrated that morin binds with high affinity to site II (subdomain IIIA) of BSA. Furthermore, the circular dichroism spectral results indicated that the conformation of BSA changed in the presence of morin. In addition, the effect of some common metal ions on the binding constant between morin and BSA was examined.
authors.affiliation: Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, PR China. huyj@whu.edu.cn
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Hu
authors.forename: Hua-Li
authors.initials: HL
authors.lastname: Yue
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Li
authors.forename: Si-Si
authors.initials: SS
authors.lastname: Zhang
authors.forename: E
authors.initials: E
authors.lastname: Tang
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001665:Binding Sites; D002942:Circular Dichroism; D005419:Flavonoids / Q000378:metabolism*; D008670:Metals / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D047309:Flavones
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D008670:Metals; D012710:Serum Albumin, Bovine; C008548:morin; D047309:Flavones