Development of liposome-based mimics of superoxide dismutase and peroxidase based on the "LIPOzyme" concept

An antioxidative liposome catalyst, LIPOzyme, that mimics both superoxide dismutase (SOD) and peroxidase (POD)-like activities has been developed by using liposomes modified with simple ligands (dodecanoyl-histidine, Dodec-His) and metal ions (Mn). The SOD-like activity is dependent on the stability of the ligand-metal complex on the liposome membrane, with the value being higher for the DPPC liposome and at a higher pH. The POD-like activity was found to be maximal in the case of DMPC liposome, in which the ligand-metal complex is inserted more deeply into the membrane. It was thus shown that liposome modified with simple ligands can exhibit different enzyme-like activities depending on the characteristics of the liposome membrane.