6y0r
Chitooligosaccharide oxidase
Structural highlights
FunctionCHITO_GIBZE Catalyzes the selective oxidation of C1 hydroxyl moieties on chitooligosaccharides with concomitant reduction of molecular oxygen to hydrogen peroxide. This results in the formation of the corresponding lactones, which typically undergo spontaneous hydrolysis. Chitooligosaccharides are homo- or heterooligomers of N-acetylglucosamine (GlcNAc) and D-glucosamine which are linked through beta-1,4-glycosidic bonds. For optimal substrate binding at least 2 GlcNAc units are needed, and chitooligosaccharide oxidase is most efficient on chitobiose, chitotriose and chitotetraose.[1] Publication Abstract from PubMedChitooligosaccharide oxidase (ChitO) is a fungal carbohydrate oxidase containing a bicovalently bound FAD cofactor. The enzyme is known to catalyse the oxidation of chitooligosaccharides, oligomers of N-acetylated glucosamines derived from chitin degradation. In this study, the unique substrate acceptance was explored by testing a range of N-acetyl-D-glucosamine derivatives, revealing that ChitO preferentially accepts carbohydrates with a hydrophobic group attached to C2. The enzyme also accepts streptozotocin, a natural product used to treat tumours. Elucidation of the crystal structure provides an explanation for the high affinity towards C2-decorated glucosamines: the active site has a secondary binding pocket that accommodates groups attached at C2. Docking simulations are fully in line with the observed substrate preference. This work expands the knowledge on this versatile enzyme. Analysis of the structure and substrate scope of chitooligosaccharide oxidase reveals high affinity for C2-modified glucosamines.,Savino S, Jensen S, Terwisscha van Scheltinga A, Fraaije MW FEBS Lett. 2020 Jun 3. doi: 10.1002/1873-3468.13854. PMID:32491191[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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