Spectroscopic Investigation On The Interaction Between Antibiotic Drugs And Bovine Serum Albumin

In this paper, the antagonism between cefazolin (CFZ) and lomefloxacin (LMF) withbovine serum albumin (BSA), the synergy between sulfadiazine (SD) andciprofloxacin(CPFX) with BSA, and the interaction between Cefminox and BSA in thepresence of cadmium ion were studied by fluorescence quenching in combination withUV-Vis spectroscopic method under simulative physiological conditions. The fluorescencequenching constants, binding distance, and binding constants for these systems weredetermined. Synchronous fluorescence, three dimensional fluorescence and circular dichroism(CD) spectra showed that the above ligands could change the conformation of BSA. Thispaper was divided into the following four chapters:Chapter one: The article summarizes the profile of serum albumin and antibiotics, theprinciple for studying the interaction between drug and protein by fluorescence spectrometrycombined with ultraviolet spectroscopy and circular dichroism method, as well as the contentand significance of this article.Chapter two: The interaction of lomefloxacin (LMF) and/or cefazolin (CFZ) with bovineserum albumin (BSA) was studied by fluorescence spectroscopy in combination with UV-Visspectroscopic method and circular dichroism (CD) spectra under simulative physiologicalconditions. The fluorescence quenching of BSA by addition of LMF and/or CFZ is due tostatic quenching and energy transfer. The fluorescence quenching constants, binding distance,and binding constants for BSA–LMX and/or CFZ systems were determined. The combinativeability for BSA–LMX was greater than BSA–CFZ, and that for two-coexisting CFZ and LMFwith BSA was greater than single with that. Two-coexisting CFZ and LMF may lead to theantagonism.Chapter three: The interaction of sulfadiazine (SD) and/or ciprofloxacin (CPFX) withBSA was studied by fluorescence spectroscopy in combination with UV-Vis spectroscopicmethod and circular dichroism (CD) spectra under simulative physiological conditions. Thefluorescence quenching of BSA by addition of CPFX and/or SD is due to static quenching andenergy transfer. The fluorescence quenching constants, binding distance, and bindingconstants for BSA–CPFX and/or SD systems were determined. The combinative ability forBSA–SD was greater than BSA–CPFX, and that for two-coexisting CPFX and SD with BSAwas less than single with that. The competitive experiments with ibuprofen, warfarin and digoxin as specific probe suggested that the primary binging site for SD and CPFX was alllocated at siteⅡ. Two-coexisting CPFX and SD may lead to the synergy.Chapter four: The interaction of Cefminox and BSA was studied by fluorescencespectroscopy in combination with UV-Vis spectroscopic method and circular dichroism (CD)spectra under simulative physiological conditions. The influence of Cd ion on the interactionbetween Cefminox and BSA was also studied. The fluorescence quenching of BSA byaddition of Cefminox is due to static quenching and energy transfer. The fluorescencequenching constants, binding distance, and binding constants for BSA–Cefminox system weredetermined at different temperatures. The results indicate that the hydrogen bonding and vander Waals interaction play important roles in the binding. The competitive experiments withibuprofen, warfarin and digoxin as specific probe suggested that the primary binging site forCefminox was located at site III in sub-domain IIIA of BSA. The binding distance betweenBSA and Cefminox was estimated to be1.09nm. The conformational change of BSA in theprescence of Cefminox and Cd ion were observed by synchronous fluorescence,three-dimensional fluorescence spectra and CD spectra.