title: A series of novel rare Earth molybdotungstosilicate heteropolyoxometalates binding to bovine serum albumin: spectroscopic approach.
abstract: Heteropolyoxometalate complexes have been widely applied in many fields. In this paper, the interaction between a series of novel rare earth molybdotungstosilicate heteropolyoxometalates, K(10)H(3)[Ln(SiMo(6)W(5)O(39))(2)].xH(2)O (abbr. LnW(5), Ln = Pr (x = 30), Gd (x = 29), Dy (x = 28), and Yb (x = 31)), and bovine serum albumin (BSA) was investigated by spectroscopic approach under the physiological conditions. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by LnW(5) is a result of the formation of LnW(5)-BSA complex. Fluorescence quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between LnW(5) and BSA. The binding affinity ranked in the order GdW(5) > DyW(5) > PrW(5) > YbW(5). The results of thermodynamic parameters DeltaG, DeltaH, and DeltaS at different temperatures indicate that van der Waals interactions and hydrogen bonds play a major role for LnW(5)-BSA association. Furthermore, the distance r between donor (BSA) and acceptor (LnW(5)) was obtained according to fluorescence resonance energy transfer.
authors.affiliation: Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi, 435002, People's Republic of China.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Hu
authors.forename: Yu
authors.initials: Y
authors.lastname: Ou-Yang
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Bai
authors.forename: Ru-Ming
authors.initials: RM
authors.lastname: Zhao
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
mesh_terms: D008674:Metals, Rare Earth / Q000737:chemistry*; D008982:Molybdenum / Q000737:chemistry*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D017973:Tungsten Compounds / Q000737:chemistry*
chemical_list: D008674:Metals, Rare Earth; D017640:Silicates; D017973:Tungsten Compounds; D012710:Serum Albumin, Bovine; D008982:Molybdenum