Pyranose oxidase

Function

Pyranose oxidase or pyranose 2-oxidase (P2O) catalyzes the conversion of D-glucose and molecular oxygen to 2-dehydro-D-glucose and H₂O₂. It is abundant in lignin-degrading white rot fungi. P2O is a tetramer flavoprotein containing the prosthetic group FAD in each monomer. P2O oxidizes several aldopyranoses with the preferred electron donors being D-glucose, D-xylose and D-sorbose^[1].

Relevance

Converting common sugars and sugar derivatives with P2O provides a pool of sugar-derived intermediates for the synthesis of rare sugars, fine chemicals and drugs.

Structural highlights

The active site of P2O is gated by a highly conserved loop which determines the substrate specificity. Water molecules are shown as red spheres. The active site contains the FAD cofactor^[2].