Study On The Interaction Between Organ-Pesticide Molecules And Bovine Serum Albumin

The intermolecular action between small molecules and biomacromolecules is one of the essential matters in life science. However, less attention has been paid to the interaction between pesticides and biomacromolecules.In this dissertation, the fluorescence spectroscopy combined with UV-visible absorption Spectroscopy were used to investigate the interaction of several small pesticide molecules with bovine serum albumin.The study including three parts as fellows:1. The structures, functions and natures of BSA were briefly introduced.The contents and methods of interaction of different kind of small ligands with protein were reviewed. And the binding of pesticide molecules and BSA were studied especially.2. The fluorescence quenching characteristic of three pyrethroid insecticide molecules and BSA were discussed, The experimental results revealed that three pyrethroid insecticide molecules all quench the intrinsic fluorescence of BSA through a dynamic quenching procedure; the non-radiative energy transfer is attributed to BSA intrinsic fluorescence being quenched also; The thermodynamic parameters results showd that van der Waals force or hydrogen bond formation can be the main type of driving forces in CYH-BSA interaction and FVR-BSA system, hydrophobic forces can be the main type of driving forces in FPR-BSA interaction; Based on the informations above, the main conclusions are summarized the allyl trifluorin substitute, more methyls substitute and chlorobenzene substitute in three medicines strctrure are the probable acting groups in medicine-BSA interaction, The process of medicine-BSA binding is promoted strongly by both the allyl trifluorin and more methyls substituted, but the chlorobenzene substitute may be decreased the process of medicine-BSA binding.The effect of metal ions and adscititious reagents on the interaction characteristic between BSA and pyrethroid insecticide molecules were investigated. The results showed that metal ions and adscititious reagents changed the interaction characteristic of three pyrethroid insecticide molecules and BSA ,such as quenching constant, the association constant, the number of herbicides binding sites, the spatial distance between medicine molecules and the fluorescence residues of BSA, and the efficiency of intermolecular energy transfer, the main type of driving force, etc. It proved that the metal ions and the adscititious reagents have some effect on the interaction between three pyrethroid insecticide molecules and BSA.3. The binding characteristic between three phenylurea herbicide molecules and BSA were studied.The results showed that DUR,LNR can quench the intrinsic fluorescence of BSA through a dynamic quenching procedure and the quenching type between FNR-BSA was static quenching; The thermodynamic parameters results showd that the process of herbicides-BSA interaction is a spontaneous molecular process in which entropy increases and Gibbs free energy decreases. Except for this, The main sort of binding force between DUR-BSA,LNR-BSA,and the dipole-dipole forces also the main type of driving force in FNR-BSA interaction,this phenomenon increased the binding contants between FNR-BSA; It is proved that these herbicides all have no effect on the second conformation of BSA by synchronous fluorescence spectra.The effect of several bioinorganic ions on the interaction characteristic between BSA and phenylurea herbicides molecules were investigated. The experiment results showed that the quenching constant and binding constant between DUR-BSA,LNR-BSA were increased in the presence of these bioinorganic ions at 298K and the quenching constant between FNR-BSA were induced; The thermodynamics parameter showed the process of medicine herbicides-BSA interaction is also a spontaneous molecular process in which entropy increases and Gibbs free energy decreases, but these ions changed the size or the type of the main type between herbicides -BSA; The absorption spectra of herbicides -Me indicated that the ions can interact with the herbicides .