title: Probing the binding of scutellarin to human serum albumin by circular dichroism, fluorescence spectroscopy, FTIR, and molecular modeling method.
abstract: The binding of scutellarin with human serum albumin (HSA) was investigated at four temperatures, 296, 303, 310, and 318 K, by fluorescence, circular dichroism (CD), Fourier transform infrared spectroscopy (FT-IR), and molecular modeling study at pH 7.40. The binding parameters were determined by Scatchard's procedure, which are approximately consistent with the results of Stern-Volmer equation. The thermodynamic parameters were calculated according to the dependence of enthalpy change on the temperature as follows: DeltaH degrees is a small negative value (-8.55 kJ/mol), whereas DeltaS degrees is a positive value (65.15 J/mol K). Quenching of the fluorescence HSA in the presence of scutellarin was observed. Data obtained by fluorescence spectroscopy and CD experiment, FT-IR experiment, and molecular modeling method suggested that scutellarin can strongly bind to the HSA and the primary binding site of scutellarin is located in site I of HSA. It is considered that scutellarin binds to site I (subdomain II) mainly by a hydrophobic interaction and there are hydrogen bond interactions between the scutellarin and the residues Arg222 and Arg257.
authors.affiliation: Department of Chemistry, Lanzhou University, 730000, China.
authors.forename: Jianniao
authors.initials: J
authors.lastname: Tian
authors.forename: Jiaqin
authors.initials: J
authors.lastname: Liu
authors.forename: Wenying
authors.initials: W
authors.lastname: He
authors.forename: Zhide
authors.initials: Z
authors.lastname: Hu
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Yao
authors.forename: Xingguo
authors.initials: X
authors.lastname: Chen
mesh_terms: D047310:Apigenin / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D002942:Circular Dichroism / Q000379:methods*; D005965:Glucuronates / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding / Q000502:physiology; D012709:Serum Albumin / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
chemical_list: D005965:Glucuronates; D012709:Serum Albumin; C484876:scutellarin; D047310:Apigenin