Catalytically active bovine serum amine oxidase bound to fluorescent and magnetically drivable nanoparticles

Novel superparamagnetic maghemite nanoparticles (SAMNs, surface active maghemite nanoparticles), characterized by a diameter of 10  2 nanometers, were modified with bovine serum amine oxidase, using rhodamine-isothiocyanate adduct as fluorescent spacer arm. A fluorescent and magnetically drivable adduct comprising bovine, copper containing, amine oxidase immobilized on the surface of specifically functionalized magnetic nanoparticles was developed (SAMN@RITC-BSAO). The multifunctional nanomaterial was characterized by transmission electron microscopy, infrared spectroscopy, mass spectrometry and activity measurements. Results showed that bare magnetic nanoparticles form stable colloidal suspension in aqueous solutions. The maximum binding capacity of bovine serum amine oxidase was about 6.4 mg g-1 nanoparticles. The immobilization procedure reduced the catalytic activity to 30  10 % with respect to the native enzyme and the Michaelis constant was increased by a factor of 2. We suggest that SAMN@RITC-BSAO complex, characterized by a specific activity of 0.81 IU g-1, could be used, in the presence of polyamines, as fluorescent magnetically drivable H2O2 and aldehydes producing system. Future applications in the selective tumor cells destruction might be suggested.