Immobilization of superoxide dismutase onto ordered mesoporous silica nanoparticles and improvement of its stability

In recent years, greater attention has been given to the application of mesoporous materials to the immobilization of enzymes. In this study, the immobilization of superoxide dismutase (SOD) onto the amine-functionalized cubic Ia3d mesoporous silica nanoparticles (n-PrNH₂-KIT-6]) with an average pore diameter of around 6.5?nm was investigated. This organo-functionalized mesoporous silica was prepared using a non-ionic surfactant and was fully characterized by SEM, XRD, nitrogen adsorption?Cdesorption isotherm and FT-IR spectroscopy. UV?Cvisible spectroscopy studies demonstrated that the immobilized SOD was less prone to thermally induced aggregation than the free moiety. Further investigations using far-circular dichroism measurement intensity indicated that the structure of SOD before and after immobilization onto the n-PrNH₂-KIT-6] nanoparticles was almost identical and the immobilized enzyme was more stable against GdHCl denaturation relative to the free one.