Purification and covalent immobilization of benzaldehyde lyase with heterofunctional chelate-epoxy modified magnetic nanoparticles and its carboligation reactivity

摘要

In this work, histidine-tagged recombinant benzaldehyde lyase from Pseudomonas fluorescens Biovar 1 (BAL, EC 4.1.2.38) was immobilized on the magnetically responsive epoxy-chelate magnetic support following a two-step mechanism; that is, the protein is physically adsorbed and then the covalent bonding takes place. This mechanism has been exploited to combine the selectivity of metal chelate affinity chromatography with the covalent immobilization capacity of epoxy supports. In this way, it has been possible to accomplish, in a simple manner, the purification, immobilization, and stabilization of a histidine-tagged recombinant benzaldehyde lyase. To fulfill this objective we prepared and characterized a multifunctional Co~(2+)-IDA-epoxy functionalized the silica coated magnetic nanoparticles (SCMPs) which are modified with glycidyloxypropyltrimethoxysilane (GPTMS) and iminodiacetic acid (IDA). To test immobilized BAL, benzoin condensation reaction was performed with this magnetically responsive biocatalyst. The results obtained from the carboligation reaction that was performed with this simple and convenient heterogeneous biocatalyst were comparable to that of free-enzyme-catalyzed reaction. Additional advantages are its reusability and it is easy to work with.