Inactivation of o-diphenoloxidase in the pyrocatechol oxidation reaction
Butovich, I.A.; Tertykh, V.A.
Ukrainskii Biokhimicheskii Zhurnal 56(5): 527-532
1984
ISSN/ISBN: 0201-8470 PMID: 6438852 Document Number: 241194
The inactivation kinetics of o-diphenoloxidase isolated from potato tubers was studied in the process of pyrocatechol oxidation. The enzyme when saturated with the substrate is inactivated with the inactivation rate constant kin = 0.5-1.0 min-1; kin depends on the initial concentration of pyrocatechol. The ultimate yield of the enzymic reaction product increases linearly with the initial concentration of the enzyme. Introduction of ethylene-diaminosulphate, a substance which condenses with o-quinones, does not increase the operation stability of o-diphenoloxidase. The data obtained evidence for inactivation of o-diphenoloxidase either at the level of the enzyme-substrate complex or due to bimolecular reaction with the substrate.