Open AccessThis article is
- freely available
Covalent Immobilization of Bacillus licheniformis γ-Glutamyl Transpeptidase on Aldehyde-Functionalized Magnetic Nanoparticles
Department of Applied Chemistry, National Chiayi University, 300 Syuefu Road, Chiayi City 60004, Taiwan
Department of Life Sciences and Institute of Molecular Biology, National Chung Cheng University, Chiayi County 621, Taiwan
These authors contributed equally to this work.
* Authors to whom correspondence should be addressed.
Received: 15 January 2013; in revised form: 20 February 2013 / Accepted: 21 February 2013 / Published: 26 February 2013
Abstract: This work presents the synthesis and use of surface-modified iron oxide nanoparticles for the covalent immobilization of Bacillus licheniformis γ-glutamyl transpeptidase (BlGGT). Magnetic nanoparticles were prepared by an alkaline solution of divalent and trivalent iron ions, and they were subsequently treated with 3-aminopropyltriethoxysilane (APES) to obtain the aminosilane-coated nanoparticles. The functional group on the particle surface and the amino group of BlGGT was then cross-linked using glutaraldehyde as the coupling reagent. The loading capacity of the prepared nanoparticles for BlGGT was 34.2 mg/g support, corresponding to 52.4% recovery of the initial activity. Monographs of transmission electron microscopy revealed that the synthesized nanoparticles had a mean diameter of 15.1 ± 3.7 nm, and the covalent cross-linking of the enzyme did not significantly change their particle size. Fourier transform infrared spectroscopy confirmed the immobilization of BlGGT on the magnetic nanoparticles. The chemical and kinetic behaviors of immobilized BlGGT are mostly consistent with those of the free enzyme. The immobilized enzyme could be recycled ten times with 36.2% retention of the initial activity and had a comparable stability respective to free enzyme during the storage period of 30 days. Collectively, the straightforward synthesis of aldehyde-functionalized nanoparticles and the efficiency of enzyme immobilization offer wide perspectives for the practical use of surface-bound BlGGT.
Keywords: Bacillus licheniformis; γ-glutamyl transpeptidase; magnetic nanoparticle; 3-aminopropyltriethoxysilane; covalent immobilization
Citations to this Article
Cite This Article
MDPI and ACS Style
Chen, Y.-Y.; Tsai, M.-G.; Chi, M.-C.; Wang, T.-F.; Lin, L.-L. Covalent Immobilization of Bacillus licheniformis γ-Glutamyl Transpeptidase on Aldehyde-Functionalized Magnetic Nanoparticles. Int. J. Mol. Sci. 2013, 14, 4613-4628.
Chen Y-Y, Tsai M-G, Chi M-C, Wang T-F, Lin L-L. Covalent Immobilization of Bacillus licheniformis γ-Glutamyl Transpeptidase on Aldehyde-Functionalized Magnetic Nanoparticles. International Journal of Molecular Sciences. 2013; 14(3):4613-4628.
Chen, Yi-Yu; Tsai, Ming-Gen; Chi, Meng-Chun; Wang, Tzu-Fan; Lin, Long-Liu. 2013. "Covalent Immobilization of Bacillus licheniformis γ-Glutamyl Transpeptidase on Aldehyde-Functionalized Magnetic Nanoparticles." Int. J. Mol. Sci. 14, no. 3: 4613-4628.