ABSTRACT
Under different temperatures and physiological conditions, with cefuroxime axetil concentrations in the range of 1.959 X 10(-6) to 13.71 X 10(-6) mol x L(-1), and bovine serum albumin (BSA) concentrations at 2.0 X 10(-6) mol x L(-1), the interaction between cefuroxime axetil and BSA was studied by fluorescence spectroscopy, three-dimensional fluorescence spectrum, synchronous fluorescence spectrum and UV-Vis absorption spectroscopy. After analyzing and processing the fluorescence quenching data at different temperatures according to Sterm-Volmer equation, Lineweaver-Burk equation and thermodynamic equation, the average value of the apparent binding constant (K(LB): 3.907 X 10(6) L x mol(-1)), and thermodynamics parameters (enthalpy change delta H: -13.43 kJ x mol(-1), entropy change delta S: 81.90 J x K(-1) and standard Gibbs free energy change delta G0: -38.34 kJ x mol(-1)) were calculated, and the amounts of binding sites (n: 1.042)were measured. The fluorescence quenching mechanism of BSA after cefuroxime axetil was added was discussed. BSA was bound with cefuroxime axetil and formed a new compound. The quenching belonged to static fluorescence quenching. The thermodynamic parameters agree with delta H approximately 0, delta S > 0 and delta G0 < 0, and the binding reaction is mainly entropy-driven and electro-static interaction force plays a major role in the reaction. The maximum emission wavelength of Tyr and Trp had an obvious red shift in the synchronous fluorescence spectra, the fluorescence emission wavelength of two peaks had a blue shift in the three-dimensional fluorescence spectrum of BSA in the presence of cefuroxime axetil and the maximum absorbtion wavelenghs of three systems in the UV-Vis absorption spectra were obviously different. These showed that the changes in the micro-environment of Tyr and Trp and demonstrated that the conformation of BSA changed as cefuroxime axetil had been added. This provides important information for discussing the configuration modification of BSA because of the added cefuroxime axetil, and for elucidating the pharmacological effects of cefuroxime axetil and biological effects in the organism.
Subject(s)
Anti-Bacterial Agents/chemistry , Cefuroxime/analogs & derivatives , Serum Albumin, Bovine/chemistry , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Thermodynamics , Absorption , Animals , Anti-Bacterial Agents/analysis , Cattle , Cefuroxime/analysis , Cefuroxime/chemistry , Entropy , Molecular Structure , Protein Binding , Protein Conformation , Serum Albumin, Bovine/analysis , TemperatureABSTRACT
At different temperatures, the binding of naphthol green B (NGB) to bovine serum albumin (BSA) was studied by the fluorescence spectroscopy, three-dimensional fluorescence spectrum, synchronous fluorescence spectrum and ultra-violet spectrum. It was shown that this compound has a quite strong ability to quench the fluorescence from BSA. After analyzing the fluorescence quenching data according to Sterm-Volmer equation and Lineweaver-Burk equation, it was found that BSA had reacted with naphthol green B and formed a new compound, the quenching action was due to static fluorescence quenching, and the action force was electrostatic interaction. According to the Lineweaver-Burk equation and thermodynamic equation, the average value of the binding constant (KLe: 1.411 x 10(5) L x mol(-1)), the thermodynamic parameters (DeltaHtheta: -5.707 kJ x mol(-1), DeltaGtheta: -30.25 kJ x mol(-1) and DeltaStheta: 79.95 J x K(-1)) and the amounts of binding sites (1.258) were obtained, providing important information for the research on the configuration modification of BSA because of the added naphthol green B, biological effects in a living body, and the coloration mechanism of naphthol green B.
Subject(s)
Coloring Agents/chemistry , Ferric Compounds/chemistry , Naphthalenesulfonates/chemistry , Naphthols/chemistry , Serum Albumin, Bovine/chemistry , Animals , Cattle , Protein Binding , Spectrometry, FluorescenceABSTRACT
The interaction of tricyclazole (TCZ) with beta-cyclodextrin (beta-CD) and human serum albumin (HSA) were studied by fluorescence spectrum, UV-visible spectrum and second-order scattering technology. It was shown that TCZ has quite a strong ability to quench the fluorescence launching from HSA by reacting with it and forming a certain kind of new compound. The quenching and the energy transfer mechanisms were discussed, respectively. The binding constants and thermodynamic parameters at four different temperatures, the binding locality, and the binding power were obtained. The conformation of HSA was discussed by synchronous and three-dimensional fluorescence techniques. The inclusion reaction between beta-CD and TCZ was explored by scattering method, the inclusion constants and the thermodynamic parameters at 297 K and 311 K were figured out, respectively. The mechanism of inclusion reaction was speculated and linkage among the toxicity of TCZ, the exterior environment and its concentration was attempted to explain on molecule level.
Subject(s)
Serum Albumin/metabolism , Spectrometry, Fluorescence/methods , Thiazoles/chemistry , beta-Cyclodextrins/chemistry , Drug Interactions , Energy Transfer , Fluorescence , Humans , Hydrophobic and Hydrophilic Interactions , Molecular Structure , Protein Binding , Spectrophotometry, Ultraviolet , Thermodynamics , Thiazoles/metabolism , beta-Cyclodextrins/metabolismABSTRACT
The binding of eosin Y to bovine serum albumin (BSA) was studied by fluorescence spectroscopy and ultraviolet spectrum. It was shown that this compound has a quite strong ability to quench the fluorescence from BSA. After analyzing the fluorescence quenching data according to Sterm-Volmer equation, Lineweaver-Burk equation and thermodynamic equation at 298. 15 K, the binding constant(KLB= 3. 601 x 10(5) L x mol(-1)) and thermodynamic parameters (deltaHtheta: - 22. 66 kJ x mol(-1), deltaGtheta: -31. 30 kJ x mol(-1) and deltaStheta: 36.32 J x K(-1)were obtained, which provide important information for researching the configuration modification of BSA caused by added eosin Y, biological effects of eosin Y in a living body, and dyeing mechanism of cells.
Subject(s)
Eosine Yellowish-(YS)/chemistry , Serum Albumin, Bovine/chemistry , Animals , Cattle , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , ThermodynamicsABSTRACT
The binding of newly compounded perseleno diphenyl 2,2'-diformic acid to bovine serum albumin(BSA) was studied at different temperatures using fluorescence spectrum and UV spectrum. The fluorescence quenching data was analyzed according to Stern-Volmer equation and Lineweaver-Burk double-reciprocal equation. It was showed that this quenching complies better with the charactristic of static fluorescence quenching. The binding constant, thermodynamic parameters, and the binding spot of the compound with certain structure, coming from perseleno diphenyl 2,2'-diformic acid and bovine serum albumin, were obtained. Besides, themechanism of static fluorescence quenching and the quality of binding power were both discussed. The information of the binding mode, the mechanism of its transportation, and some medical theories in human body were offered.
Subject(s)
Organometallic Compounds/chemistry , Organoselenium Compounds/chemistry , Selenium/chemistry , Serum Albumin, Bovine/chemistry , Thermodynamics , Algorithms , Animals , Cattle , Fluorescence , Humans , Kinetics , Models, Chemical , Molecular Structure , Organometallic Compounds/metabolism , Organoselenium Compounds/metabolism , Protein Binding , Serum Albumin, Bovine/metabolism , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , TemperatureABSTRACT
The binding feature of dipyridamole with bovine serum albumin (BSA) was studied using fluorescence spectroscopy. It was shown that this compound has a powerful ability to quench the BSA fluorescence via a nonradiative energy transfer mechanism. The fluorescence quenching data were analyzed according to stern-volmer equation and double-reciprocal equation, and the binding constant and the thermodynamic parameters were obtained.
