ENZYMATIC OXIDATION OF DOPAMINE BY POLYPHENOL OXIDASE

The kinetics of the enzymic oxidation of dopamine (A) by polyphenol oxidaze (E) was studied by spectrophotometrically monitoring the concentration of the reaction product, 2,3-dihydroindole-5,6 quinone, at 470 nm. The kinetics model proposed for the reaction and the effect of pH agreed with the experimental data and the resulting rate equation is given by -d[A]/dt = 1.5081 X 10(-4)[E(o)][A]/1 + 2.0896 X 10(6)[H+] where [A] is the concentration of dopamine (mM), [E(o)] the concentration of polyphenol oxidaze (mg/1) and [H+] the concentration of hydrogen ion (M) in the reaction mixture.