title: Glucosylation of Catechol with the GTFA Glucansucrase Enzyme from Lactobacillus reuteri and Sucrose as Donor Substrate.
abstract: Lactic acid bacteria use glucansucrase enzymes for synthesis of gluco-oligosaccharides and polysaccharides (α-glucans) from sucrose. Depending on the glucansucrase enzyme, specific α-glucosidic linkages are introduced. GTFA-ΔN (N-terminally truncated glucosyltransferase A) is a glucansucrase enzyme of Lactobacillus reuteri 121 that synthesizes the reuteran polysaccharide with (α1 → 4) and (α1 → 6) glycosidic linkages. Glucansucrases also catalyze glucosylation of various alternative acceptor substrates. At present it is unclear whether the linkage specificity of these enzymes is the same in oligo/polysaccharide synthesis and in glucosylation of alternative acceptor substrates. Our results show that GTFA-ΔN glucosylates catechol into products with up to at least 5 glucosyl units attached. These catechol glucosides were isolated and structurally characterized using 1D/2D (1)H NMR spectroscopy. They contained 1 to 5 glucose units with different (α1 → 4) and (α1 → 6) glycosidic linkage combinations. Interestingly, a branched catechol glucoside was also formed along with a catechol glucoside with 2 successive (α1 → 6) glycosidic linkages, products that are absent when only sucrose is used as both glycosyl donor and acceptor substrate.
authors.affiliation: Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen , Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Evelien M
authors.initials: EM
authors.lastname: te Poele
authors.affiliation: Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen , Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Pieter
authors.initials: P
authors.lastname: Grijpstra
authors.affiliation: Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen , Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Sander S
authors.initials: SS
authors.lastname: van Leeuwen
authors.affiliation: Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen , Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Lubbert
authors.initials: L
authors.lastname: Dijkhuizen
mesh_terms: D005947:Glucose / Q000378:metabolism*; D016695:Glycosyltransferases / Q000378:metabolism*; D052200:Limosilactobacillus reuteri / Q000378:metabolism*; D066244:Proton Magnetic Resonance Spectroscopy; D013379:Substrate Specificity; D013395:Sucrose / Q000378:metabolism*
chemical_list: D013395:Sucrose; D016695:Glycosyltransferases; C033837:alternansucrase; D005947:Glucose