| As the material base of life,nucleic acids and proteins play an important role in the action of life.There are connection between nucleic acids configuration and its function.Proteins are most abundant in organism,and they attach themselves almost to all life action.The application of plant growth regulators promoted the development of modern agriculture.However,along with the continuous increase of variety and quantity of the plant growth regulators,the serial food safety and environment pollution problems coursed by the plant growth regulators residua become more and more serious,the harm to the human health and the environment courses widely international attention. At the same time,high-sensitivity detection method becomes very important to the plant growth regulators residua and their metabolites.For the seek of researching the interaction of bio-macromolecules and plant growth regulators,this thesis studied the interaction mechanism between bio-macromolecules and plant growth regulators using the research techniques including fluorescence,Resonance Light Scattering(RLS),UV absorption,circular dichroism(CD)spectrometries and transmission electron microscopy(TEM).Some rapid,accurate and handy assays were developed for plant growth regulators.This thesis was divided into five sections.In the first section,we summarized the research method and evolution of the interaction between the drugs and bio-macromolecules,the principle of RLS method and the recent developments of RLS.193 references were cited here.In the second section,the interaction between 6-Benzylaminopurine(6-BA)and bovine serum albumin(BSA)was investigated by fluorescence,UV absorption and CD spectrometries.A strong fluorescence quenching was observed and the quenching mechanism was considered as static quenching according to the Stern-Volmer equation.The binding constants of 6-BA with BSA at 293K,298K and 308K were obtained as 2.4×104,2.6×104 and 3.1×104 L/mol,respectively.There was one single binding site between 6-BA and BSA.The thermodynamic parameters enthalpy change (ΔH)and entropy change(ΔS)were calculated as 14.2 kJ/mol and 132.1 J/(mol·K), respectively,which indicated that the acting force between 6-BA and BSA were mainly hydrophobic interactions.According to the F(?)rster non-radiation energy transfer theory,the average binding distance between donor(BSA)and acceptor (6-BA)was obtained(r=2.99nm).The investigations of the UV/Vis and CD spectra of the system showed that the conformation of BSA was changed in presence of 6-BA.In the third section,the interaction mechanism of Kinetin(KT)with BSA was studied by the methods of fluorescence,fluorescence lifetime,UV absorption and CD spectrometries.KT could strongly quench the intrinsic fluorescence of BSA by static quenching.The binding constants of KT with BSA at two temperatures(288K and 303K)were obtained as 1.45×104 and 1.42×104 L/mol.The Stern-Volmer curve had an intersection at CKT=8.0×10-5mol/L,which indicated that KT bound to different binding sites on BSA.The analytical results of fluorescence data showed when CKT＜8.0×10-5mol/L,the number of binding sites was near 1,and when CKT＞8.0×10-5 mol/L,the number of binding sites was approximately 3.7.The thermodynamic parameters were calculated by Van't Hoff equation.The enthalpy change enthalpy change(ΔH)and entropy change(ΔS)were calculated at two concentration of KT. The results suggested that the hydrophobic interaction might play a main role in the interaction of KT(CKT＜8.0×10-5mol/L)with the BSA,while CKT＞8.0×10-5mol/L the hydrogen bonding and Vander Waals forces became major.The binding distance(r) between KT and tryptophan in BSA was obtained according to the F(?)rster energy transfer theory.The investigations of the UV/Vis and CD spectra of the system showed that the secondary structure of BSA was changed in presence of KT.In the fourth section,the binding characteristics and mechanism of DNA to 1-naphthlcetic acid(NAA)had been investigated by using the methods of fluorescence spectroscopy and viscosity.The spectroscopy analysis showed that DNA could quench the endogenous fluorescence of NAA.Based on the changes of fluorescence intensity and fluorescence quench formulas,the quenching constants between DNA and NAA had been worked out,and the fluorescence lifetime results showed that the quenching effect of DNA on NAA was a static fluorescence mechanism.The experimental results of viscosity,thermal denaturation,ionic strength showed that the binding mode of NAA with DNA was partial intercalation and groove binding.In the fifth section,the RLS enhancing effect of 6-BA-nanoAg-SDS was studied in HAc-NaAc(pH=4.5)buffer.It was found that 6-BA could enhance the RLS intensity of nanoAg-SDS system.Under optimum conditions,the calibration graph for 6-BA was obtained,the enhanced intensity of RLS at 350 nm was in proportion to the concentration of 6-BA in the range of 2.0×10-8-1.0×10-5mol/L.The detection limit (S/N=3)is 2.8×10-9mol/L,and the results for the determination of 6-BA in synthetic samples was satisfactory.And the interaction mechanism of 6-BA,SDS and nanoAg was studied by several techniques including TEM,measurement of conductivity,Zeta potentiometry and so on.The chief characteristics of this thesis were as follows:(1)In this thesis,we studied the interaction mechanisms between BSA and plant growth regulators using fluorescence,fluorescence lifetime,UV absorption and CD spectrometries,which enriched the research in the fields of pesticide.(2)In this thesis,we used variety methods of fluorescence spectroscopy, absorption spectroscopy and viscosity to investigate the binding characteristics and mechanism between DNA and NAA.(3)The RLS enhancement of system of 6-BA-nanoAg-SDS was studied,which was utilized to determine of trace amount 6-BA.The method was simple,rapid and also had a wide concentration linear range.Several instruments were used to study the interaction mechanism of the system such as fluorescence,UV absorption and TEM.
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