Fluorescence Anisotropy Study Of Small Organic Molecules And Serum Albumin Binding Role

Protein plays an important part in life process. Serum albumin(SA) is a kind of protein which can bind with intrinsic and extrinsic materials, and transfers them to every parts of the body. The study of the interaction between small organic molecules especially drugs, and serum albumin is distinctively important in the clinic medicine and life science.Fluorescence anisotropy methods have become firmly entrenched, particularly for bioanalytical applications. However, there are not many studies which investigate the association between small organic molecule and serum albumin by fluorescence anisotropy technology. Furthermore, in my opinion, the existing studies in this domain have some limitations.In this thesis, we studied the interactions between organic molecules and SA by fluorescence anisotropy. Through measuring the fluorescence anisotropy of 5-sulfosalicyclic(SSA), we acquired the number of binding sites and association constant of BSA-SSA in the method of linear regression. The results we got mainly agree with the ones we got by another method. We also did some explorations in determining rF (the fluorescence anisotropy of the free SSA molecules): we added some reagent into the system of organic molecules and SA to hinder their association, therefore, most of the organic molecules were free and the anisotropy we got from this system was closer to rF.The systems of SSA-HSA and ATA (Aurintricarboxylic acid)-BSA were studied by" similar method. The results were that the number of binding sites between SSA and HSA was 1, and the number of binding sites between ATA and BSA was 3 .It's difficult to investigate the association between Ce3+ and SA by measuring fluorescence identity because their fluorescence spectrums interfere with each other.We studied the Ce3+-BSA system by fluorescence anisotropy and synchronous fluorescence spectra. By the method of molar ratio, it was deduced that the number of binding sites was 2.In a series of solutions of Ce3+-BSA, the quantity of Ce3+ was fixed, whereas the quantity of BSA was increased. We found complex changes in the synchronous fluorescence spectra of Ce3+. However, if we fixed the quantity of BSA, and increased Ce3*, there was no change in the synchronous fluorescence spectra of BSA. The reason was probably that the binding sites of Ce were not close to tryptophane and tyrosine so that the association couldn't cause changes in the surroundings of tryptophane and tyrosine.