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Surface-functionalized hyperbranched poly(amido acid) magnetic nanocarriers for covalent immobilization of a bacterial γ-glutamyltranspeptidase.
- Source :
-
Molecules (Basel, Switzerland) [Molecules] 2014 Apr 22; Vol. 19 (4), pp. 4997-5012. Date of Electronic Publication: 2014 Apr 22. - Publication Year :
- 2014
-
Abstract
- In this study, we synthesized water-soluble hyperbranched poly(amido acid)s (HBPAAs) featuring multiple terminal CO2H units and internal tertiary amino and amido moieties and then used them in conjunction with an in situ Fe2+/Fe3+ co-precipitation process to prepare organic/magnetic nanocarriers comprising uniformly small magnetic iron oxide nanoparticles (NP) incorporated within the globular HBPAAs. Transmission electron microscopy revealed that the HBPAA-γ-Fe2O3 NPs had dimensions of 6-11 nm, significantly smaller than those of the pristine γ-Fe2O3 (20-30 nm). Subsequently, we covalently immobilized a bacterial γ-glutamyltranspeptidase (BlGGT) upon the HBPAA-γ-Fe2O3 nanocarriers through the formation of amide linkages in the presence of a coupling agent. Magnetization curves of the HBPAA-γ-Fe2O3/BlGGT composites measured at 300 K suggested superparamagnetic characteristics, with a saturation magnetization of 52 emu g⁻¹. The loading capacity of BlGGT on the HBPAA-γ-Fe2O3 nanocarriers was 16 mg g⁻¹ support; this sample provided a 48% recovery of the initial activity. The immobilized enzyme could be recycled 10 times with 32% retention of the initial activity; it had stability comparable with that of the free enzyme during a storage period of 63 days. The covalent immobilization and stability of the enzyme and the magnetization provided by the HBPAA-γ-Fe2O3 NPs suggests that this approach could be an economical means of depositing bioactive enzymes upon nanocarriers for BlGGT-mediated bio-catalysis.
- Subjects :
- Enzyme Stability
Equipment Reuse
Escherichia coli chemistry
Escherichia coli enzymology
Escherichia coli genetics
Hydrogen-Ion Concentration
Kinetics
Particle Size
Recombinant Proteins chemistry
Temperature
Bacterial Proteins chemistry
Enzymes, Immobilized chemistry
Ferric Compounds chemistry
Magnetite Nanoparticles chemistry
Nylons chemistry
gamma-Glutamyltransferase chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1420-3049
- Volume :
- 19
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Molecules (Basel, Switzerland)
- Publication Type :
- Academic Journal
- Accession number :
- 24759067
- Full Text :
- https://doi.org/10.3390/molecules19044997