Studies On The Interaction Mechanism Of Ponceau S And Drugs With Bovine Serum Albumin By Fluorescence Spectroscopy

The interaction between drugs and BSA has been an intensively research of biological and chemistry. This paper has carried on the study about the mechanism of Ponceau S and drugs with bovine serum albumin by fluorescence spectroscopy. It was divided into five chapters:Chapter one: This section actuality of interaction between small molecules with serum albumin by fluorescence spectroscopy and UV-visible absorption spectroscopy. The kinds of spectroscopic probes were reported. The development and application of the interaction and spectroscopic probes were described. 94 references were cited here.Chapter two: Luminescence spectroscopy study of conjugation reaction between bovine serum albumin and spectroscopic probe ponceau S. Ponceau S (PS) could quench the fluorescence of bovine serum albumin (BSA) in the aqueous solution of pH=7.40. The static fluorescence quenching process between BSA and PS was confirmed and the binding constant, the number of binding sites and thermodynamic parameters between BSA and PS were obtained. It showed that the number of binding sites was 1 and the electrostatic attraction played an important role in the binding of BSA to PS. Based on the theory of F(o|¨)rester spectroscopy energy transfer, the binding distance (r<7.0 nm) between PS and BSA was obtained. Studies utilizing synchronous spectra showed that the conjugation reaction between PS and BSA would affect the conformation of BSA, leading to the polarity around tyrosine residues weakened and the hydrophobicity strengthened. The site markers competitive experiments indicated that the binding of PS to BSA primarily took place in sub-domainⅡA (siteⅠ).Chapter three: Conjugation reaction between bovine serum albumin and neomycin with ponceau S as fluorescence probe. A conjugation reaction between bovine serum albumin (BSA) and the neomycin (NM) with ponceau S (PS) as fluorescent probe by the fluorescence spectroscopy and UV-visible absorption spectroscopy was studied. Studies had indicated that fluorescence quenching was occurred between the BSA and PS. The static fluorescence quenching process was confirmed and the binding constant, the number of binding sites and the type of interaction force of BSA with PS were obtained. It was interesting that the relative fluorescence intensity of BSA was recovered gradually with increasing concentration of NM. The reaction mechanism was studied.Chapter four: Study on the conjugation reaction between bovine serum albumin and gentamicin with Ponceau S as fluorescence probe. Ponceau S (PS) could quench the fluorescence of bovine serum albumin (BSA) in the aqueous solution of pH=7.40. The static fluorescence quenching process between BSA and PS was confirmed and the binding constant, the number of binding sites and thermodynamic parameters between BSA and PS were obtained. It showed that the number of binding sites was 1 and the electrostatic attraction played an important role in the binding of BSA to PS. Based on the theory of F?rester spectroscopy energy transfer, the binding distance (r?7.0 nm) between PS and BSA was obtained. The site markers competitive experiments indicated that the binding of PS to BSA primarily took place in sub-domainⅡA (siteⅠ). It showed that there was no obvious fluorescence intensity change by combining BSA and gentamicin (GM), so the conjugation reaction between BSA and GM cannot be studied by spectroscopy. It was observed that when GM was added into BSA-PS system, the relative fluorescence intensity of the system was recovered gradually with increasing concentration of gentamicin, which showed that there existed conjugation reaction between GM and BSA and the binding of GM to BSA primarily took place in sub-domainⅡA (siteⅠ).Chapter five: Study on interaction of cefoperazone sodium with ofloxacin in the presence of BSA by fluorescence spectroscopy. Interaction mechanism of cefoperazone sodium (CFP) and ofloxacin (OFX) with bovine serum albumin (BSA) at different temperatures by fluorescence spectrometry method was studied. Results showed that CFP or OFX could quench the fluorescence of BSA. The fluorescence would quench to a larger degree when OFX (or CFP) was added to the system of BSA-CFP (or BSA-OFX). The quenching mechanism of the combination for BSA and drugs was a static procedure. The number of binding sites is 1 in various systems. The values of nH were approximately equal to 1. It was proved that the interaction between CFP and OFX simultaneously bound to BSA was weaker and almost no cooperativeness occurred. The site markers competitive experiments indicated that the binding of CFP and OFX to BSA primarily took place in siteⅠ. Thermodynamic parameters were also used to identify the force type of drugs with BSA.