title: Characterization of two-step deglycosylation via oxidation by glycoside oxidoreductase and defining their subfamily.
abstract: Herein, we report a two-step deglycosylation mediated by the oxidation of glycoside which is different from traditional glycoside hydrolase (GH) mechanism. Previously, we reported a novel flavin adenine dinucleotide (FAD)-dependent glycoside oxidoreductase (FAD-GO) having deglycosylation activity. Various features of the reaction of FAD-GO such as including mechanism and catalytic residue and substrate specificity were studied. In addition, classification of novel FAD-GO subfamily was attempted. Deglycosylation of glycoside was performed spontaneously via oxidation of 3-OH of glycone moiety by FAD-GO mediated oxidation reaction. His493 residue was identified as a catalytic residue for the oxidation step. Interestingly, this enzyme has broad glycone and aglycon specificities. For the classification of FAD-GO enzyme subfamily, putative FAD-GOs were screened based on the FAD-GO from Rhizobium sp. GIN611 (gi 365822256) using BLAST search. The homologs of R. sp. GIN611 included the putative FAD-GOs from Stenotrophomonas strains, Sphingobacterium strains, Agrobacterium tumefaciens str. C58, and etc. All the cloned FAD-GOs from the three strains catalyzed the deglycosylation via enzymatic oxidation. Based on their substrate specificities, deglycosylation and oxidation activities to various ginsenosides, the FAD-GO subfamily members can be utilized as novel biocatalysts for the production of various aglycones.
authors.affiliation: 1] School of Chemical and Biological Engineering, Institute of Molecular Biology and Genetics, and Bioengineering Institute, Seoul National University, Seoul, 151-742, Korea [2].
authors.forename: Eun-Mi
authors.initials: EM
authors.lastname: Kim
authors.affiliation: 1] School of Chemical and Biological Engineering, Institute of Molecular Biology and Genetics, and Bioengineering Institute, Seoul National University, Seoul, 151-742, Korea [2].
authors.forename: Joo-Hyun
authors.initials: JH
authors.lastname: Seo
authors.affiliation: School of Chemical and Biological Engineering, Institute of Molecular Biology and Genetics, and Bioengineering Institute, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Kiheon
authors.initials: K
authors.lastname: Baek
authors.affiliation: School of Chemical and Biological Engineering, Institute of Molecular Biology and Genetics, and Bioengineering Institute, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Byung-Gee
authors.initials: BG
authors.lastname: Kim
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D006027:Glycosides / Q000378:metabolism*; D006031:Glycosylation; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D006027:Glycosides; D010088:Oxidoreductases