FIG. 2.

Enzymatic formation of 2-amino-5-methylmuconate by the action of partially purified 2-amino-5-methylmuconic semialdehyde dehydrogenase (fraction 17). 2-Amino-5-methylmuconic semialdehyde (A₃₈₂) was instantly produced from 2-amino-4-methylphenol (0.05 mM) by the 2-aminophenol 1,6-dioxygenase of strain JS45 (0.31 mg of protein per ml). The reaction mixture also contained potassium phosphate (50 mM, pH 8.0), fraction 17 (0.084 mg of protein per ml), and 0.2 mM NAD⁺. Recordings were taken at 0.5-min intervals. The A₃₂₆ increased during the course of the reaction.