title: Combined multispectroscopic and molecular docking investigation on the interaction between delphinidin-3-O-glucoside and bovine serum albumin.
abstract: Anthocyanin is one of the flavonoid phytopigments with specific health benefits. The interaction between delphinidin-3-O-glucoside (D3G) and bovine serum albumin (BSA) was investigated by fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, circular dichroism spectroscopy and molecular modeling. D3G effectively quenched the intrinsic fluorescence of BSA via static quenching. The number of binding sites and binding constant Ka were determined, and the hydrogen bonds and van der Waals forces played major roles in stabilizing the D3G-BSA complex. The distance r between donor and acceptor was obtained as 2.81 nm according to Förster's theory. In addition, the effects of pH and metal ions on the binding constants were discussed. The results studied by synchronous fluorescence, three-dimensional fluorescence and circular dichroism experiments indicated that the secondary structures of the protein has been changed by the addition of D3G and the α-helix content of BSA decreased (from 56.1% to 52.4%). Furthermore, the study of site marker competitive experiments and molecular modeling indicated that D3G could bind to site I of BSA, which was in the large hydrophobic cavity of subdomain IIA.
authors.affiliation: School of Life Science, Shandong Normal University, Jinan, People's Republic of China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Zuo
authors.forename: Lin
authors.initials: L
authors.lastname: Tang
authors.forename: Shu
authors.initials: S
authors.lastname: Li
authors.forename: Junwei
authors.initials: J
authors.lastname: Huang
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000737:chemistry*; D002417:Cattle; D002942:Circular Dichroism; D005960:Glucosides / Q000737:chemistry*; D062105:Molecular Docking Simulation; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000872:Anthocyanins; D005960:Glucosides; D012710:Serum Albumin, Bovine; C494120:delphinidin 3-O-glucopyranoside
keywords: bovine serum albumin; delphinidin-3-O-glucoside; molecular modeling; multispectroscopic