PEI-crosslinked lipase on the surface of magnetic microspheres and its characteristics
Yi-Ping Cao1, Yu-Pei Xia1, Xiao-Fei Gu1
1College of Pharmaceutical Science, Hebei University, Baoding, 071002, China.
Abstract:
Here, PEI@PMMA microspheres were prepared by grafting polyethyleneimine (PEI) on poly(methyl methacrylate) (PMMA) magnetic microspheres and successfully used to immobilize lipase. The results showed that PEI@PMMA microspheres had strongly adsorbed lipase (49.1 mg/g microsphere) via electrostatic attraction. To prevent lipase shedding, the adsorbed lipase was further crosslinked with PEI on microspheres using glutaraldehyde as crosslinker. Consequently, PEI-crosslinked lipase (2.14 U/mg) exhibited 2.6 times and 1.4 times higher activity respectively than the directly covalent lipase (0.82 U/mg) and the crosslinked lipase aggregates (1.57 U/mg), which was close to the activity of adsorbed lipase (2.20 U/mg). Conformational analysis from FTIR spectroscopy showed that PEI-crosslinked lipase retained its natural structure well. And the α-helix structure seemed to play a key role in enhancing lipase activity. Furthermore, the effects of various parameters on crosslinking reaction were investigated. Also, PEI-crosslinked lipase revealed higher pH and thermal stability. The Michaelis constant (Km) was increased and the optimum temperature of lipase was widened observably after crosslinking with PEI on PEI@PMMA magnetic microspheres.
Insights
Immobilized lipase using polyethyleneimine (PEI) on magnetic microspheres enhances enzyme activity and stability. This PEI-crosslinked lipase shows improved performance compared to other immobilization methods.
Area of Science:
- Biotechnology
- Materials Science
- Enzyme Engineering
Background:
- Enzyme immobilization is crucial for industrial applications, requiring stable and active enzyme preparations.
- Polyethyleneimine (PEI) and poly(methyl methacrylate) (PMMA) magnetic microspheres offer potential for efficient enzyme carrier systems.
- Improving lipase activity, stability, and reusability through effective immobilization strategies is an ongoing research area.
Purpose of the Study:
- To develop a novel method for immobilizing lipase onto PEI-grafted PMMA magnetic microspheres.
- To enhance the activity and stability of immobilized lipase through crosslinking with PEI.
- To investigate the structural and functional properties of the PEI-crosslinked immobilized lipase.
Main Methods:
- Preparation of PEI-grafted PMMA magnetic microspheres.
- Immobilization of lipase onto the microspheres via electrostatic attraction.
- Crosslinking of immobilized lipase using glutaraldehyde and PEI.
- Enzyme activity assays, conformational analysis (FTIR), and stability tests (pH, thermal).
Main Results:
- PEI@PMMA microspheres effectively adsorbed lipase (49.1 mg/g).
- PEI-crosslinked lipase exhibited significantly higher activity (2.14 U/mg) compared to directly covalent (0.82 U/mg) and aggregated lipase (1.57 U/mg).
- The crosslinked enzyme retained its natural structure, with alpha-helix content potentially enhancing activity, and showed improved pH and thermal stability.
Conclusions:
- PEI-grafted PMMA magnetic microspheres provide an effective platform for lipase immobilization.
- PEI-mediated crosslinking significantly enhances lipase activity and stability, offering a promising approach for enzyme engineering.
- The developed method yields a robust biocatalyst with potential for various industrial applications.
More Related Videos
09:38Fabrication Procedures and Birefringence Measurements for Designing Magnetically Responsive Lanthanide Ion Chelating Phospholipid Assemblies
Published on: January 3, 2018
08:39Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release
Published on: July 4, 2017