title: Azido derivatives of cellobiose: oxidation at C1 with cellobiose dehydrogenase from Sclerotium rolfsii.
abstract: We report the chemo-enzymatic synthesis of three cellobiono-1,5-lactone azido derivatives, designed as building blocks for biomedical polymer scaffolds. The synthesis is based on regioselective protection of cellobiose or 1,6-O-anhydro-β-d-cellobiose before azidation and subsequent deprotection. The oxidation to the corresponding cellobiono-1,5-lactones was investigated with 6'-azido-6'-deoxycellobiose (6'N3Clb, 5), 6-azido-6-deoxycellobiose (6N3Clb, 11) and 2-azido-2-deoxycellobiose (2N3Clb, 15) under the catalysis of cellobiose dehydrogenase (CDH) from the plant-pathogenic fungus Sclerotium rolfsii. Substrate binding characteristics and kinetics of CDH for the three cellobiose azido derivatives were studied employing computational docking, steady-state and presteady-state techniques. The process of enzymatic oxidation of the cellobiose azido intermediates was optimized by using the available kinetic information. Whereas the conversion of 15 by CDH is very slow, the conversion of 5 and 11 by a regenerated, bi-enzymatic process (CDH/redox mediator/laccase/O2) is fast, quantitative and produces azido derivatives of cellobiono-1,5-lactone in an environmentally friendly, oxygen-driven process.
authors.affiliation: Department of Pharmacy, Faculty of Medicine, University of Prishtina, QKUK, Prishtina 10000, Republic of Kosovo, Serbia.
authors.forename: Dafina
authors.initials: D
authors.lastname: Mulla
authors.forename: Daniel
authors.initials: D
authors.lastname: Kracher
authors.forename: Roland
authors.initials: R
authors.lastname: Ludwig
authors.forename: Gabor
authors.initials: G
authors.lastname: Nagy
authors.forename: Melanie
authors.initials: M
authors.lastname: Grandits
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Holzer
authors.forename: Yasser
authors.initials: Y
authors.lastname: Saber
authors.forename: Nermeen
authors.initials: N
authors.lastname: Gabra
authors.forename: Helmut
authors.initials: H
authors.lastname: Viernstein
authors.forename: Frank M
authors.initials: FM
authors.lastname: Unger
mesh_terms: D001203:Ascomycota / Q000201:enzymology* / Q000472:pathogenicity; D001386:Azides / Q000737:chemistry*; D002237:Carbohydrate Dehydrogenases / Q000737:chemistry / Q000378:metabolism*; D002475:Cellobiose / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D007700:Kinetics; D007783:Lactones / Q000737:chemistry; D062105:Molecular Docking Simulation; D010084:Oxidation-Reduction; D011487:Protein Conformation; D013379:Substrate Specificity
chemical_list: D001386:Azides; D007783:Lactones; D002475:Cellobiose; D002237:Carbohydrate Dehydrogenases; C019859:cellobiose-quinone oxidoreductase
keywords: Azidocellobiose; Cellobiose dehydrogenase; Chemo-enzymatic synthesis; Molecular docking; Sclerotium rolfsii; Substrate specificity