Kinetic calculations in the enzymatic resolution of DL-amino acids

The literature contains several papers describing the kinetic mechanism of the optical resolution of N-acetylo-DL-amino acids catalyzed by L-aminoacyl ase. Most authors propose ar eversible Michaelis-Menten kinetic reaction sc heme inhibited by substrate and products. Such studies are mostly based on initial rate measurements. In this paper an alternative method is presented to determine both the reaction scheme and the value of the involved consta nts. The method is based on measuring product concentration for different i nitial substrate concentrations up until the time when equilibrium is reach ed and on the numerical integration of the late equation. The optical resol ution of N-acetyl-DL-phenylalanine and N-acetyl-DL-valine catalyzed by L-am inoacylase were used as model systems to check the validity of the proposed method, and a slightly substrate-inhibited reversible Michaelis-Menten rea ction scheme was demonstrated. In disagreement with other previously publis hed studies, no product inhibition was detected Previous experiments were p erformed to determine the most suitable enzyme concentration and the optima l concentration of the activator Co2+. (C) 1999 Elsevier Science Inc. All r ights reserved.