Enzyme Activity Measurement for Pyranose Oxidase Using Spectrophotometric Assays

Creative Enzymes is well known for the leading techniques and extensive experiences in the enzyme service area. We are particularly specialized in customized enzyme activity measurement. The most up-to-date spectrophotometric instrument is used to assure the utmost quality of our services. Creative Enzymes promises that we will provide the most accurate and timely enzyme activity assays for pyranose oxidase.

Pyranose oxidase (P2O) (EC 1.1.3.10; glucose 2-oxidase, pyranose-2-oxidase) is an enzyme that catalyzes the oxidation of D-glucose and several other aldopyranoses at C-2 position to produce 2-dehydro-D-glucose and other corresponding 2-ketoaldoses, concomitant with the reduction of O₂ to H₂O₂. It is widely distributed among wood-degrading basidiomycetes. Pyranose oxidase has been isolated and characterized from several microorganisms, such as Phanerochaete chrysosporium, Phlebiopsis gigantea, Trametes versicolor, and some unidentified basidiomycetes. In general, pyranose oxidase is a relatively large, homotetrameric protein which is bound to flavin adenine dinucleotide (FAD) covalently. This enzyme is classified as a member of the glucose-methanol-choline (GMC) oxidoreductase family based on sequence and structure analysis. Pyranose oxidase is localized preferentially in the hyphal periplasmic space and considered to be a major source of endogenous H₂O₂, necessary cosubstrate of lignin-degrading peroxides. The systematic name of this enzyme class is pyranose:oxygen 2-oxidoreductase.

In vivo, the substrates of pyranose oxidase include D-glucose, D-galactose, and D-xylose, which are abundant in lignocellulose and are oxidized to 2-keto-d-glucose, 2-keto-d-galactose, and 2-keto-d-xylose, respectively. Moreover, pyranose oxidase also oxidizes some other carbohydrates, such as L-sorbose, D-glucono-1,5-lactone, and D-allose. The substrates vary to some extent when pyranose oxidase is isolated from different fungi. For recent few years, pyranose oxidase has become more and more important as a key catalyst in analytical, diagnostic, and carbohydrate chemistry. Pyranose oxidase can be used in the quantitative analysis of D-glucose in blood as a key component of glucose biosensors. In addition, this enzyme is also considered as a diagnostic enzyme in clinical chemistry because it can react with 1,5-anhydro-D-glucitol, an important marker for glycemic control in diabetes patients.

Overall, more detailed knowledge of pyranose oxidase is desired by many researchers, especially the catalytic mechanisms and kinetics. Creative Enzymes is proud to provide enzyme activity measurement of high accuracy for our customers. Our spectrophotometric assay is demonstrated to be a highly reliable method. Pyranose oxidase activity is determined at 420 nm by measuring the formation of H₂O₂ spectrophotometrically. With our extensive experiences, Creative Enzymes will be your reliable partner in scientific research and product development involving pyranose oxidase.

Figure: The crystal structure of pyranose oxidase from Trametes ochracea.
PDB: 1TT0