Spectroscopic Studies On The Interaction Of Bovine Serum Albumin With Gliclazide,Gliquidone And Colistin Sulfate

In recent years, people take more attention on the health status and drugs. Studying the interaction of protein and drugs is the major way to explore the property of drugs and protein. In this paper, bovine serum albumin and drugs were studies as the research object. Several spectroscopic methods were used to study the bovine serum albumin-drug systems. The difference and the respective advantages of various methods were presented. The research content has been divided into five sections:Chapter one: In this chapter, the commonly used methods for the protein-drug systems were introduced. The development of the field of protein-drugs was illustrated, with 45 literatures quoted.Chapter two: At three temperatures, the interaction between gliclazide and bovine serum albumin was investigated using fluorescence and synchronous fluorescence spectroscopy by monitoring bovine serum albumin. From the experimental results, it was found that the quenching mechanism was static. The values of Ka were all 104, n were equal to 1, implying threr was a one high affinity binding site in the interaction; the primary binding site for gliclazide was located in sub-domain IIA of bovine serum albumin; electrostatic interaction may play a major role in the association process; Hill coefficients were almost 1, indicating a noncooperative reaction; the binding rate of gliclazide(W) was similar. The results obtained by the two methods were similar, indicating synchronous fluorescence spectroscopy can be used to reflect the change of protein, and inform the mechanism between protein and drugs.Chapter three: At different temperatures, the interaction between gliclazide and bovine serum albumin was investigated using resonance light scattering spectroscopy and UV/vis absorption spectroscopy by monitoring gliclazide. The results indicated that the quenching mechanism between bovine serum albumin and gliclazide was static. The values of quenching constants, thermodynamic parameters and Hill coefficient were calculated. The values of binding constant obtained from resonance light scattering and UV/vis absorption spectroscopy were much greater than the values obtained from fluorescence quenching spectroscopy, indicating the methods monitoring gliclazide were more accurate and reasonable. In addition, it implied that there were other residues(besides tryptophan and tyrosine) involved in the reaction and the mode "point to surface" existed in the interaction.Chapter four: Gliquidone interacting with bovine serum albumin in physiological buffer(pH 7.4) was investigated using fluorescence quenching spectroscopy and synchronous fluorescence spectroscopy by minotoring bovine serum albumin. The experimental results indicated that the quenching mechanism between bovine serum albumin and gliquidone was static, and the electrostatic interaction played an important role in the interaction. In addition, the quenching constants, the thermodynamic parameters and Hill coefficients were calculated at different temperatures. Comparing the results from fluorescence quenching and synchronous fluorescence spectroscopy, we found the mechanism and conclusion were similar. It also indicates synchronous fluorescence spectroscopy can be used to reflect the microenvironment change of protein, and inform the mechanism between protein and drugs.Chapter five: At three temperatures, the interaction between colistin sulfate with bovine serum albumin in physiological buffer was investigated using resonance light scattering spectroscopy by monitoring bovine sernm albumin. The results indicated that quenching mechanism of the system was probably static. The value of n was approximately 1, indicating there was only a single class of binding sites on BSA for colistin sulfate compounds. The thermodynamic parameters implied that the interaction was spontaneous and electrostatic force played a major role in the system. From the values of nH, it can be seen that there was non-cooperative reaction in the system. Comparing the data from two menthods, it was found that the quenching reactive parameters from two methods were similar, suggesting resonance light scattering spectroscopy was feasible. Resonance light scattering spectroscopy can be used to explore the substance without intrinsic fluorescence, suggesting that the application of resonance light scattering spectroscopy broaden the understanding of the interaction between small molecules and protein.