| en |
Immobilization of horseradish peroxidase on Fe3O4 magnetic nanoparticles
Mohamed, Saleh A.; Harbi, Majed H. al-; Almulaiky, Yaaser Q.; Ibrahim, Ibrahim H. & Shishtawy, Reda M. el-
Abstract
Background: Iron magnetic nanoparticles have attracted much attention. They have been used in enzyme
immobilization because of their properties such as product is easily separated from the medium by magnetic
separation. The present work was designed to immobilize horseradish peroxidase on Fe3O4 magnetic
nanopraticles without modification.
Results: In the present study, horseradish peroxidase (HRP) was immobilized on non-modified Fe3O4 magnetic
nanoparticles. The immobilized HRP was characterized by FT-IR spectroscopy, scanning electron microscopy,
and energy dispersive X-ray. In addition, it retained 55% of its initial activity after 10 reuses. The optimal pH
shifted from 7.0 for soluble HRP to 7.5 for the immobilized HRP, and the optimal temperature shifted from
40°C to 50°C. The immobilized HRP is more thermostable than soluble HRP. Various substrates were oxidized
by the immobilized HRP with higher efficiencies than by soluble HRP. Km values of the soluble and
immobilized HRP were 31 and 45 mM for guaiacol and 5.0 and 7.0 mM for H2O2, respectively. The effect of
metals on soluble and immobilized HRP was studied. Moreover, the immobilized HRP was more stable against
high concentrations of urea, Triton X-100, and isopropanol.
Conclusions: Physical immobilization of HRP on iron magnetic nanoparticles improved the stability toward the
denaturation induced by pH, heat, metal ions, urea, detergent, and water-miscible organic solvent.
Keywords
Activity; Energy dispersive X-ray; FT-IR spectroscopy; Immobilized enzymes; Immobilized; Iron; Magnetic separation; pH; Protein immobilization; Scanning electron microscopy; Soluble horseradish peroxidase
|
