Glycosidic Bond Hydroxylation by Polysaccharide Monooxygenases

Polysaccharide monooxygenases (PMOs) are mononuclear Cu enzymes that have been intensely studied since the discovery of their role in the oxidative degradation of polysaccharides. PMOs can activate either O-2 or H2O2 to hydroxylate the strong C-H bond alpha to the glycosidic linkage of various polysaccharides. Many recent advances in our understanding of these enzymes including structure-function relationships, cosubstrate-dependent chemical mechanisms, and electron transfer mediators are the focus of this review. This has led to a clearer view of the reaction chemistry surrounding PMO catalysis.