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.