Pulsed Amperometric Detection of Microdialysates from the Glucose Oxidase Reaction

Abstract

Microdialysis is used for in vitro characterization of the glucose oxidase reaction. A microdialysis block, which is designed to accept a wide range of commercially available flat membranes, is mated with high-performance anion-exchange chromatography (HPAEC) followed by pulsed amperometric detection (PAD) to directly and continuously monitor the concentration of glucose over time. Glucose is sampled at 5-min intervals, and the initial velocity is determined from the first 10% of the reaction profile. The Michaelis constant, K m, was determined to be 10 mM. This technique is generally applicable to the study of exo- and endoglycosidases and other enzyme reactions with carbohydrate-based substrates.