Different concentrations of the substrate GL, ranging from 0.375 to 4 mM, were prepared to determine the kinetic constants. The catalytic reactions were continuously monitored, and the initial velocities were fitted to the Michaelis-Menten equation using the Origin 7.5 software (OriginLab). The values of the Michaelis-Menten constant (Km), maximal velocity (Vmax), catalytic turnover rate (Kcat), and catalytic efficiency (Kcat/Km) were evaluated.