Kinetic study of immobilized ω-transaminase for the asymmetric synthesis of chiral amine

Abstract

Biocatalysis is a powerful tool for the synthesis of high value products such as, chiral molecules and intermediates. Chiral amines can be synthesized by kinetic resolution of racemic amines or by the asymmetric synthesis from pro-chiral ketones. Kinetic parameter estimation for biocatalytic reaction is useful to evaluate process and technology options. In this work, the Michaelis–Menten kinetic parameters of immobilized ω-transaminase on methacrylate beads for the asymmetric synthesis of (R)-1-phenylethylamine (PEA) from acetophenone (ACP) and alanine (ALA) were determined. The parameters such as, MichaelisMenten constant (Km) and maximum rate of reaction (Vmax) were measured from initial rate experiments by varying ACP concentrations (2 mM to 10 mM) at a fixed 100 mM ALA under mild reaction conditions (pH 7.5 and temperature 30 °C). The concentration of ACP and PEA were measured by gas chromatography. Lineweaver-burk plot was used to estimate the Vmax and Km from the initial rate data. The results yielded a Vmax of 6.87 mM/min and a Km of 2.52 mM. The Michaelis-Menten model is useful for understanding the kinetic properties of immobilized enzymes.