Enzyme Activity Measurement for Galactose Oxidase

Having tested activities of numerous oxidoreductases in the past several years, Creative Enzymes has accumulated extensive and specialized experiences, which make us capable of providing the high-quality service of enzyme activity measurement. Our efficient and accurate assays cover a wide range or oxidoreductases, including galactose oxidase. The activity assays are performed on the most advanced analytic instrument using spectrophotometric analysis.

Galactose oxidase (EC 1.1.3.9; GAO, GAOX, GOase; D-galactose:oxygen 6-oxidoreductase, D-galactose oxidase, beta-galactose oxidase) is a monomeric 65-68 kDa enzyme that contains a single copper ion and an amino acid-derived cofactor. Galactose oxidase has been classified as a member of the newly established auxiliary activity (AA) family, AA5, and subfamily AA5_2. This enzyme was first detected in cultivation media of Polyporus circinatus, which was later identified as Dactylium dendroides, a mycoparasite of P. circinatus. And D. dendroides was later reclassified as Fusarium graminearum, which is the most extensively studied with galactose oxidase.

Galactose oxidase catalyzes the oxidation of primary alcohols to corresponding aldehydes with strict regioselectivity, and the selectivity is highest for the galactose C-6 primary hydroxyl group. However, galactose oxidase accepts various primary alcohols such as benzyl alcohol, and glycerol as the reducing substrates. Galactose oxidase displays remarkable stereospecificity in its reaction with sugars, and it shows activity with galactose but not with glucose. Due to this specificity, a wide variety of analytical tools are developed based on this enzyme, such as the determination of lactose in milk and dairy products or histochemical examination of mucus-secreting cells. Moreover, galactose oxidase has also been used in biosensors for the measurement of galactose. Furthermore, galactose oxidase serves as a competitive and cost-effective catalyst in food and pharmaceutical industries. An interesting application for galactose oxidase is for the modification of cell surface carbohydrates. Therefore it can be used in cell labeling and histochemical staining.

Due to the multiple applications of galactose oxidase in biotechnological, food and pharmaceutical industries, more detailed knowledge about this enzyme is much desired, especially for the catalytic mechanism. Hence, Creative Enzymes is proud to provide the accurate spectrophotometric activity assays for galactose oxidase. We are a group of outstanding scientists who have been working on enzyme activity assays for many years. Extensive and professional experiences help us receive a good reputation from the enzyme service market. Creative Enzymes will always provide the assay services of high satisfaction and utmost quality.

Figure: The crystal structure of galactose oxidase from Fusarium graminearum.
PDB: 2EIB