1.1.99.29 a pyranose + acceptor = a pyranos-2-ulose (or a pyranos-3-ulose or a pyranos-2,3-diulose) + reduced acceptor - - 1.1.99.29 a pyranoside + acceptor = a pyranosid-3-ulose (or a pyranosid-3,4-diulose) + reduced acceptor - - 1.1.99.29 a pyranoside + acceptor = a pyranosid-3-ulose (or a pyranosid-3,4-diulose) + reduced acceptor requires FAD, a number of aldoses and ketoses in pyranose form, as well as glycosides, gluco-oligosaccharides, sucrose and lactose can act as donor, 1,4-benzoquinone or ferricenium ion (ferrocene oxidized by removal of one electron) can serve as acceptor, unlike EC 1.1.3.10, pyranose oxidase, this fungal enzyme does not interact with O2 and exhibits extremely broad substrate tolerance with variable regioselectivity (C-3, C-2 or C3 + C-2 or C-3 + C-4) for (di)oxidation of different sugars, D-glucose is exclusively or preferentially oxidized at C-3 (depending on the enzyme source), but can also be oxidized at C-2 + C-3, the enzyme also acts on 1-4-alpha- and 1-4-beta-gluco-oligosaccharides, non-reducing gluco-oligosaccharides and L-arabinose, which are not substrates of EC 1.1.3.10, sugars are oxidized in their pyranose but not in their furanose form 644544