An integrated approach for the detailed characterization of an immobilized enzyme

Publication date: Available online 8 January 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Filipe Carvalho, Patrizia Paradiso, Benilde Saramago, Ana Maria Ferraria, Ana Maria Botelho do Rego, Pedro Fernandes Enzyme immobilization has been the focus of extensive research over decades, yet empiricism still often prevails over rational design. To overcome this pattern and develop high performance, cost-effective systems, a trend towards a more comprehensive characterization of the heterogeneous bioconversion systems is emerging. This work encompasses such scope. The model system is the immobilization of invertase on glass substrate for the production of invert sugar syrup through sucrose hydrolysis. Before invertase immobilization, the glass substrates were cleaned and hydroxylated; next, substrate functionalization was performed by incubation with (3-Aminopropyl)triethoxysilane and glutaraldehyde. Detailed characterization was performed by monitoring every step of the immobilization protocol by contact angle measurement, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy. Enzyme loading and affinity towards the functionalized substrate was evaluated with a quartz crystal microbalance. The successful deposition of the different coating reagents and of the enzyme was confirmed by the shifts in surface wettability and roughness. XPS highlighted the over-simplistic nature of common models for chemical interaction between layers. ...

Source: Journal of Molecular Catalysis B: Enzymatic - January 12, 2016 Category: Biochemistry Source Type: research