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Affinity immobilization of a genetically engineered bifunctional hybrid protein
F Baneyx1, C Schmidt, G Georgiou
1Department of Chemical Engineering, University of Texas, Austin 78712.
Enzyme and Microbial Technology
|May 1, 1990
Summary
This study demonstrates that a hybrid protein, combining Protein A and beta-lactamase, can be effectively immobilized on IgG-Sepharose. This affinity immobilization enhances enzyme stability and activity for potential applications.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzyme Engineering
Background:
- Protein A (SpA) from Staphylococcus aureus binds the Fc domain of immunoglobulin G (IgG).
- Recombinant DNA technology enables the creation of hybrid proteins combining SpA with enzymes like beta-lactamase.
Purpose of the Study:
- To characterize the functional properties of a novel Protein A-beta-lactamase hybrid protein immobilized on IgG-Sepharose.
- To compare the performance of the immobilized hybrid protein with its solution form and covalently immobilized beta-lactamase.
Main Methods:
- Construction of a recombinant Protein A-beta-lactamase hybrid protein.
- Affinity adsorption of the hybrid protein onto IgG-coated Sepharose matrices.
- Enzymatic assays measuring penicillin G hydrolysis.
- Stability studies including thermal deactivation and storage.
Main Results:
- The hybrid protein demonstrated tight, specific binding to IgG-Sepharose, with stable storage for at least 4 weeks.
- Immobilization on IgG-Sepharose resulted in increased specific activity and lower Km values compared to covalently immobilized beta-lactamase.
- The immobilized hybrid protein exhibited enhanced stability against thermal deactivation.
Conclusions:
- Bifunctional hybrid proteins offer a viable strategy for affinity immobilization of enzymes.
- This approach improves enzyme stability and catalytic efficiency.
- The Protein A-beta-lactamase system shows promise for enzyme immobilization applications.