Catalytic And Immobilization Of Oxalate Oxidase

Oxalate oxidase (OxOx) can catalyze the decomposition of oxalate to hydrogen peroxide and carbon dioxide. It has a number of potential applications, including medical diagnosis and treatments for hyperoxaluria and other oxalate-related diseases. There are still some unknown questions regarding to the catalytic mechanism of OxOx, though the structure and catalysis of the OxOx have been extensively studied..In this thesis, the binding site of the metal ions on the OxOx surface and the substrate binding site of the OxOx were determined by using the effect of Cu2+, Ca2+, Fe2+, Fe3+, Mn2+, and Zn2+ metal ions on the actaivity of OxOx, the physical and chemical properties of the metal ions, especially Fe3+, the crystal structure of OxOx, and molecular docking.In addition, OxOx immobilization on the novel nanomaterials graphene oxide and reduced graphene oxide was studied. The catalytical and physical properties, and the performance of the immobilized enzymes were investigated systematically. The immobilized enzyme retained 100% of the initial activity. The enzyme loading on the two materials were 1.7 mg OxOx/lmg GO and 6 mg OxOx/lmg RGO, respectively. In addition to that, the RGO immobilized OxOx maintains 100% relative activity after 10 cycles, which is much better than that of the reported immobilized OxOx in the literature. Compared with the native OxOx, the immobilized enzyme showed greater temperature stability, and wider pH range, thua the immobilized OxOx should have broad applications in the oxalate detection.