Spectral Properties About The Interaction Between Transferrin And Cefuroxime Sodium,Cefotaxime Sodium,Cefoxitin Sodium

On present days,people demand for more drugs because of the impact from environment.The study on drugs is being concerned.Proteins play an important role in the transportation of drugs.Only by proteins,drugs can play their roles in body.So it is essential to study interaction mechanism of proteins and drugs.Here,interaction on transferrin and cephalosporin drugs was studied.This text consists of the following sections:Chapter one: In this chapter,we have been refered to 34 articles.Many different researching methods on studying binding mechanism of protein macromolecule-drug molecule(fluorescence quenching method,UV absorption spectroscopy,circular dichroism spectroscopy)have been explained in this chapter.Also,multiple functions of protein have been demonstrated in this chapter.Chapter two: Transferrin was regarded as study object in this chapter.The interaction between cefuroxime sodium and transferrin in physiological buffer(pH 7.4)was investigated by spectroscopy at 298,310,and 318 K.The order of magnitude of binding constants(Ka)was 104,and the number of binding site(n)in the binary system was approximately equal to 1.So,with the increasing of temperature,stability of the products has been reduced.The fluorescence quenching process is static.?S>0,?G<0,so it is spontaneous during the interaction process.Chapter three: The fluorescence change of Transferrin(TRF)was regarded as the study object.At different temperatures(298,310 and 318 K),the interaction between TRF and CEM was studied by UV absorption spectroscopy,fluorescence spectroscopy,synchronous fluorescence spectroscopy and circular dichroism spectroscopy.Data processed and analysed has indicated that the fluorescence of TRF was regularly quenched upon the addition of CEM.The quenching pattern was static.TRF and CEM were combined by electrostatic interaction.New compound was formed during the process.These different methods verify the accuracy and rationality of results.In addition,synchronous fluorescence spectroscopy and circular dichroism spectroscopy both showed the conformation of TRF was influenced by CEM.Chapter four: The fluorescence change of TRF,BSA was regarded as the study object.At different temperatures(298,310 and 318 K),the interaction between TRF,BSA and CSI was studied by multiple methods.With the increasing of CSI concentration,absorbance of BSA-CSI,TRF-CSI becomes smaller and the highest peak position respectly has 3nm,5nm redshift.So,new compounds have formed in TRF-CSI,BSA-CSI system.Fluorescence quenching of TRF-CSI,BSA-CSI system is static.The binding of TRF,BSA with CSI has affected ?-helix structure of TRF,BSA and has loosed the peptide chains.When molar ratio of TRF,BSA to CSI were 1:0,1:10,1:40,the bands intensities of transferrin at 208 and 222 nm decreased with the increasing of CSI without causing any significant shift of the peaks,this demonstrated ?-helical secondary structure decreased upon the reaction of CSI with TRF,BSA.So,?-helical structure still plays a dominant role.Chapter five: TRF was regarded as studied objiect in this chapter.The mechanism of TRF-CFS system has been studied.Results showed that Ka becomes smaller with the increasing of reaction temperature.That the stability of TRF-CFS compounds was reduced could be inferred.Because of ?H < 0,?S > 0,electrostatic force is the main binding force between TRF and CFS.Results showed that the level of fluorescence quenching(?ex =280 nm)was larger than the level of fluorescence quenching(?ex =295 nm).Trp,Tyr in TRF both took part in reaction.