Study On The Interaction Of Small Biomolecules With Mimic Biomembrane By Electrochemistry Method

In this dissertation, the progress of the research of biomembrane has been reviewed. Some fundamental properties and theories in this field are introduced. Electrochemical methods have been used to study the mimic biomembrane system—supported bilayer lipid membranes (s-BLM). The main results are as follows:1. Supported bilayer lipid membrane(s-BLM) was served as a biomembrane model. The interaction between sodium deoxycholate(NaDC) and s-BLM was investigated by means of cyclic voltammetry(CV) and ac impedance spectroscopy(EIS). The following conclusions were obtained: NaDC can decrease the orderliness of lecithin molecule and induce pores or defects on s-BLM. The interaction depends on time, concentration, pH and cholesterol. The defective s-BLM after interaction can be self-repaired in 0.1 mol/L KCl solution, which indicates that the interaction is reversible.2. The interaction between s-BLM and hydroxyl free radical (·OH) produced by Fenton system was investigated by means of CV. The following conclusions were obtained:·OH can induce pore or defect on s-BLM through chemical interaction with lecithin. The interaction depends on time, concentration of FeSO4 and H2O2, moreover, it is not reversible. The antioxidants including vitamin C, glutathione and L-cysteine can suppress·OH by reductive radicals, therefore, it decrease the destructive degree of the structrue of s-BLM.3. The interaction between s-BLM and·OH was investigated by CV and atom force microscope(AFM) including the protective effect of vitamin E and EDTA.·OH can induce pore or defect on s-BLM through chemical interaction with lecithin. In CV experiments, we find that: s-BLM containing vitamin E produces much intenser hindrance to prober molecule . So it can be concluded that the vitamin E can suppress·OH by reductive radicals. EDTA added into Fenton system can restrain·OH by having complex reaction with ferrous ion, consequently it can protect s-BLM.