In enzymology, a pyranose oxidase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are D-glucose and oxygen. Its products are glucosone and hydrogen peroxide.
Pyranose oxidase is able to oxidize D-xylose, L-sorbose, D-galactose, and D-glucono-1,5-lactone, which have the same ring conformation and configuration at C-2, C-3 and C-4. It can use oxygen, but also ferrocene ions, quinones and 2,6-dichlorophenolindophenol as oxidizers.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with oxygen as acceptor. The systematic name of this enzyme class is pyranose:oxygen 2-oxidoreductase. Other names in common use include glucose 2-oxidase, and pyranose-2-oxidase. This enzyme participates in pentose phosphate pathway. It employs one cofactor, FAD.
As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , and .
Recently, pyranose oxidase has been gaining on popularity within biosensors. Unlike glucose oxidase, it can produce higher power output, given that it is not glycosylated, has more favorable value of Michaelis-Menten constants, and can catalytically convert both anomers of glucose. It reacts with a wider range of substrates. Pyranose oxidase does not cause an unwanted pH shift. It is also possible to easily express and produce it in high yields using E. coli.