Carboligation reactivity of benzaldehyde lyase (BAL,EC 4.1.2.38) covalently attached to magnetic nanoparticles

Epoxy-functionalized Fe₃O₄–SiO₂ core–shell magnetic nanoparticles (epoxy-M-support) were prepared by modification with glycidyloxypropyltrimethoxysilane (GPTMS) and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and fourier transform infrared spectroscopy (FTIR) methods. Pure histidine-tagged recombinant benzaldehydelyase (BAL, EC 4.1.2.38) was efficiently immobilized onto the epoxy-M-support with covalent binding. An immobilized BAL epoxy-M-support system was tested to catalyze the self and cross condensation reactions of aldehydes, and the kinetic resolution of racemic acyloins. The acyloin products were obtained in high yield and with high enantiomeric excesses (?98% ee). The carboligation reactivity of the immobilized enzyme was comparable to that of free enzyme-catalyzed reactions. The covalent immobilization offers high enzyme activity and stability (at least 5 repeats without losing its activity).