Modeling and Validation of an Unusual Kinetic Phenomenon During the Enzymatic Hydrolysis of Lactose to Glucose

摘要

An experiment is described in which a custom made glucose electrode is used to directly monitor the enzymatic hydrolysis of lactose to glucose. The transient profile of bate-D-glucose can be used to simultaneously determine the rate constants for mutarotation and for enzymatic hydrolysis by applying non-linear regression. Due to differences in the mutarotation rate constants between lactose and glucose, the bate-D-glucose 'overshoots'equilibrium under certain conditions which can be modeled mathematically. The adaptation of a platinization method to make highly sensitive electrodes with a fast time response allows this 'overshoot' to be observed reliably. Results obtained in this analysis may be important for the analysis of dairy processing operations and/or commercial lactase enzymes, and provide an elegant illustration of an unusual kinetic phenomenon caused by intramolecular forces.