A Study On The Promotion Of Different Forms Of Iron On Lipidperoxidation And Protein Oxidation In Lipid-protein System

The deleterious of iron has been given much more attention in recent years. Many articles have focused on the oxidative injury induced by iron ion. In this thesis,different forms of iron in living body, i.e. Fe³⁺, hemin and hemoglobin are chosen, to study the nature of Fe(III)-H₂O₂ system on inducing lipid peroxidation and BSA oxidation of BSA-liposom system. The main results in this work are as follows:The efficiencies of hemin, hemoglobin and Fe³⁺ on inducing CD and MDA production in BSA-lipid system were studied. In addition, the effects of hemin, hemoglobin and Fe³⁺ systems on BSA oxidation were also discussed. At last, the degradation of hemin and hemoglobin were determinated. The results showed that acidic condition favored lipid peroxidation. Hemin and hemoglobin were more effectively on MDA production when compared to Fe³⁺. BSA could effectively inhibite hemin and Fe³⁺ induced lipid peroxidation in all tested pH, while showed no effect on hemoglobin induced lipid peroxidation in pH ranges of 6.0⁹.0. Similar results were obtained in CD determination. There were no obvious effect of pH on hemoglobin and Fe³⁺ induced BSA oxidation, but alkaline condition significantly promoted BSA oxidation.The effects of NaNO₂ on MDA determination by TBA colorimetric method and TBA fluorometric method were studied. The results showed that the existence of NaNO₂ had strong affections on TBA colorimetric method and TBA fluorometric method. The MDA concentrations are lower with the increasing concentrations of NaNO₂. No matter before or after the lipid peroxidation initiation, the addition of NaNO₂ all affected the determination. However, NaNO₂ showed no influence on CD production. These results indicate that NaNO₂ affects lipid peroxidation determination by TBA method but not lipid peroxidation.