Anti-lipid Oxidation Of Reactive Oxygen Species In The Micellar System And Anti-oxidant Role

Biomembrane is simulated by the three typical reverse micelles, which are AOT/isooctane, CTAB/cycle-hexane/chloroform and TritonX- 1 OO/cyclohexane/ chloroform Enzyme structure in reverse micelles was studied by the method of ultraviolet spectra, fluorescence and CD. The conformation of imidazole cycle of SOD in reverse micelles is different from in water obviously. With increasing Wo the fluorescence intensity increased until Wo1 5,and did not varied after this. The secondary structures of SOD and CAT changed with pH . When pH increasing the contents of a - helix increased, P - collapse decreased, P - corner and irregular conformation changed disorderly. When the concentration of surfactant increased the secondary structure of SOD changed hardly, But the content of a - helix of CAT decreased, P - collapse decreased, P - corner and irregular changed disorderly. The biomernbrane lipid oxidation was simulated by that of SBPC by. The 3 effects of microenviromemt were investigated on the antioxidation of SOD and CAT. The pH affects the oxidation degree of SBPC evidently. The time for losing 10% of aciivity of SOD in AOT reverse micelles was more than in buffer solution. There was a typical bell-shape profile as to relations between enzyme activities and Wo and pH. The activity of SOD did not affect by the concentration of surfactant. There was a direct correlation between the activities of CAT and Wo and pH. Vitamin E antioxidized cooperatively with SOD and CAT. Vitamin C cooperated with SOD in antioxidation~, but inhibited the activity of CAT. SOD cooperated with CAT to inhibit the oxidation of SBPC. During reaction SOD played a primary role in earlier stage and CAT did in later period.