Spectroscopic Studies On The Interaction Of Three Kinds Of Cephalosporin Drugs With Trypsin And Bovine Transferrin

In recent years,the incidence of disease of human increase with years,people take more attention on the health status and drugs.In order to better understand the pharmacological,pharmacological and targeted transport of drugs,the studying of the interaction of drug and protein has become an important topic.In this paper,with Trypsin and Bovine Transferrin as carrier protein,the interaction of protein and Cefpirome sulfate,Cefoperazone sodium,Cefonicid sodium were studied by many methods.The content was divided into five parts:Chapter one: In this paper,the commonly used methods for the protein-drug systems were introduced,and made a brief summary of Trypsin and Transferrin.It made a brief introduction of the idea of the experiments,research contents and the interaction of drugs and proteins.Chapter two: The interaction between Cefpirome sulfate and Trypsin was studied using multi-spectroscopic and molecular docking methods.The results showed that the quenching of Trypsin fluorescence by Cefpirome sulfate was a static process,the number of binding sites in this system was approximately equal to 1.The quenching curves indicated that the tyrosine and tryptophan residues were both involved in the reaction.Synchronous fluorescence spectroscopy further confirmed that the main binding site was closer to tryptophan residues.Fluorescence spectroscopy showed that the main interaction force between Cefpirome sulfate and Trypsin was electrostatic force.Molecular docking showed that the interaction forces between Cefpirome sulfate and Trypsin were electrostatic forces and hydrogen bonds.The distance(r)between Trypsin and Cefpirome sulfate was less than 7nm,which indicated that the energy transfer from Trypsin to Cefpirome sulfate was non-radiative energy transfer.The study of the Hill's coefficient showed that there was negative cooperation in the interaction of Cefpirome sulfate with Trypsin.Chapter three: The reaction mechanism of Cefpirome sulfate to Bovine Transferrin was investigated by both fluorescence quenching,synchronous fluorescence spectroscopy and ultraviolet spectroscopy.The quenching constants,binding constants and binding sitesbetween the two were determined.The main type of action between Cefpirome sulfate and Bovine Transferrin was determined by calculation of thermodynamic parameters.And the data said that the main action was electrostatic attraction.Through the calculation of Hill's coefficient,the cooperativity between Cefpirome sulfate and Bovine Transferrin was obtained,and it was negative cooperativity.Chapter four: The reaction mechanism of Cefoperazone sodium and Bovine Transferrin was investigated by both fluorescence quenching and synchronous fluorescence spectroscopy.Quenching mechanism,binding site,interaction and cooperativity were obtained from those two methods using the same equation was consistent.Comparison between the data obtained from ??=60 nm and ?ex=295 nm,indicated that the synchronous fluorescence spectroscopy had higher sensitivity and accuracy compared to conventional fluorescence spectroscopy.Therefore,synchronous fluorescence spectroscopy has greatly enriched the methods of mechanism research of small-molecule ligands and protein binding.Chapter five: In the Tris-HCl buffer solution with pH=7.4,the reaction mechanism of Cefonicid sodium with Bovine Transferrin was investigated at different temperatures.The results demonstrated that,in the Bovine Transferrin-Cefonicid sodium system,the main mode of action was a static quenching progress which generated a new complex,and the number of binding site in the system was closed to 1.Through the thermodynamic parameters,it can be seen that the electrostatic force played a dominant role in this system.Other than that,ultraviolet visible absorption spectroscopy and synchronous fluorescence spectroscopy showed that the polarity around the tryptophan residue and tyrosine residue increased and the hydrophobicity decreased.