Spectroscopic studies on the interaction of fluorine containing triazole with bovine serum albumin

Thermodynamic investigation of interaction between [(η6-p-cymene) RuII(acetone-N4-phenylthiosemicarbazone)Cl]Cl anticancer drug and human serum albumin: spectroscopic and electrochemical studies

In this contribution, the interaction between [(η (6)-p-cymene)Ru(II)(acetone-N (4)-phenylthiosemicarbazone)Cl]Cl (Ru-TSC) anticancer drug and human serum albumin (HSA) was investigated by spectroscopic and electrochemical techniques. The fluorescence spectra results indicated that Ru-TSC anticancer drug could quench the intrinsic fluorescence of HSA through dynamic quenching mode. The calculated corresponding activation energy of the interaction between Ru-TSC anticancer drug and HSA was 35.62 kJ mol(-1). The distance between HSA and Ru-TSC anticancer drug was obtained according to fluorescence resonance energy transfer. The results of synchronous fluorescence spectra, three-dimensional fluorescence spectra, Fourier transform infrared spectroscopy (FTIR) spectra, and circular dichroism (CD) spectra indicated that the microenvironment and the conformation of HSA were all changed in the presence of Ru-TSC anticancer drug. The results of cyclic voltammetry further validated the interaction between Ru-TSC and HSA. These results indicated that the biological activity of HSA was affected by Ru-TSC anticancer drug dramatically.

Lanthanide salts of heteropoly molybdotungstosilicate LnHSiMo10W2O40·xH2O (Ln = Pr, Nd, Sm, Gd, Tb, Dy, Yb) binding to bovine serum albumin: a fluorescence quenching study

In the present work, the interaction between a series of novel lanthanide salts of heteropoly molybdotungstosilicate LnHSiMo(10)W(2)O(40)·xH(2)O (LnW(2); Ln = Pr (x = 23), Nd (x = 24), Sm (x = 26), Gd (x = 20), Tb (x = 23), Dy (x = 21), Yb (x = 25)), and bovine serum albumin (BSA) was investigated by spectroscopic approach at different temperatures under imitated physiological conditions. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by LnW(2) is a result of the formation of LnW(2)-BSA complex. Binding affinity between LnW(2) and BSA was determined using Scatchard equation and the modified Stern-Volmer equation, and the corresponding electronic structure-affinity relationship were discussed. The results of thermodynamic parameters ∆G, ∆H, ∆S at different temperatures indicate that the electrostatic interactions play a major role in LnW(2)-BSA binding process. Moreover, the enthalpy change (∆H) and entropy change (∆S) were in accordance with the "enthalpy-entropy compensation" equation obtained from this and previous work. Furthermore, the distance r between donor (BSA) and acceptor (LnW(2)) was obtained according to fluorescence resonance energy transfer.