Abstract

Production, purification and characterization of glucose oxidase-an over view

Author(s): Jagdish Singh, Neelam Verma

Glucose oxidase (-D-glucose:oxygen 1-oxidoreductase; EC 1.1.3.4) is a flavoprotein which catalyses the oxidation of -D-glucose by molecular oxygen to D-glucolactone and H2O2. It has been reported from red algae, bacteria, citrus fruits, insects and moulds. Filamentous fungi synthesize GOx and it is intra- and extracellular where as Intracellular localization of GOx is a matter of discussion. GOx is a homo-dimer with molecular weight of 150-180 KDa and contains two tightly bound FAD molecules. Km value of purified GOx lies around 20-38mMand 0.25mM with glucose and dioxygen, respectively. pH optima for the enzyme depends upon the source of GOx and It is in the range from pH 3.0-7.0. GOx from Aspergillus and Penicillium spp. requires b-D-glucose as a substrate where as D-mannose, D-galactose, 2-deoxy-D-glucose and D-xylose exhibit low activity as substrates. GOx has applications in oxidation reactions and it is used clinically and analytically in the determination of glucose in body fluid such as blood and urine and desugaring of egg products and in removing oxygen from food and beverages.