title: Screening of recombinant glycosyltransferases reveals the broad acceptor specificity of stevia UGT-76G1.
abstract: UDP-glycosyltransferases (UGTs) are a promising class of biocatalysts that offer a sustainable alternative for chemical glycosylation of natural products. In this study, we aimed to characterize plant-derived UGTs from the GT-1 family with an emphasis on their acceptor promiscuity and their potential application in glycosylation processes. Recombinant expression in E. coli provided sufficient amounts of enzyme for the in-depth characterization of the salicylic acid UGT from Capsella rubella (UGT-SACr) and the stevia UGT from Stevia rebaudiana (UGT-76G1Sr). The latter was found to have a remarkably broad specificity with activities on a wide diversity of structures, from aliphatic and branched alcohols, over small phenolics to larger flavonoids, terpenoids and even higher glycoside compounds. As an example for its industrial potential, the glycosylation of curcumin was thoroughly evaluated. Under optimized conditions, 96% of curcumin was converted within 24h into the corresponding curcumin β-glycosides. In addition, the reaction was performed in a coupled system with sucrose synthase from Glycine max, to enable the cost-efficient (re)generation of UDP-Glc from sucrose as abundant and renewable resource.
authors.affiliation: Centre for Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
authors.forename: Griet
authors.initials: G
authors.lastname: Dewitte
authors.affiliation: Centre for Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Walmagh
authors.affiliation: Centre for Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
authors.forename: Margo
authors.initials: M
authors.lastname: Diricks
authors.affiliation: Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010 Graz, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lepak
authors.affiliation: Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010 Graz, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Gutmann
authors.affiliation: Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010 Graz, Austria; Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria.
authors.forename: Bernd
authors.initials: B
authors.lastname: Nidetzky
authors.affiliation: Centre for Industrial Biotechnology and Biocatalysis, Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. Electronic address: tom.desmet@ugent.be.
authors.forename: Tom
authors.initials: T
authors.lastname: Desmet
mesh_terms: D029687:Capsella / Q000235:genetics / Q000378:metabolism; D003474:Curcumin / Q000737:chemistry / Q000378:metabolism; D004795:Enzyme Stability; D006031:Glycosylation; D016695:Glycosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D036625:Stevia / Q000201:enzymology* / Q000235:genetics
chemical_list: D010940:Plant Proteins; D011994:Recombinant Proteins; D016695:Glycosyltransferases; D003474:Curcumin
keywords: Curcumin; Glycosylation; Glycosyltransferase; Stevia rebaudiana; UGT76G1