Fig. (2) Lineweaver-Burk plot for the determination of K_m and V_max for phenoloxidase oxidation of L-DOPA at room temperature. Assay conditions were 20 mM PBS (pH 6.5), containing 0.3, 0.6, 1.2, 2.4, 4.8 mM L-DOPA, and 20 µL of enzyme, total volume was 200 µL. ■: Lineweaver-Burk plot of phenoloxidase from the susceptible strain. □: Lineweaver-Burk plot of phenoloxidase from the resistant strain.