- Efficient synthesis and characterization of lactulosucrose by leuconostoc mesenteroides B-512F dextransucrase
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This work describes an efficient enzymatic synthesis and NMR structural characterization of the trisaccharide β-d-galactopyranosyl-(1→4)- β-d-fructofuranosyl-(2→1)-α-d-glucopyranoside, also termed as lactulosucrose. This oligosaccharide was formed by the
- Díez-Municio, Marina,Herrero, Miguel,Jimeno, Maria Luisa,Olano, Agustín,Moreno, F. Javier
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p. 10564 - 10571
(2013/01/15)
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- Bioengineering of Leuconostoc mesenteroides glucansucrases that gives selected bond formation for glucan synthesis and/or acceptor-product synthesis
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The variations in glucosidic linkage specificity observed in products of different glucansucrases appear to be based on relatively small differences in amino acid sequences in their sugar-binding acceptor subsites. Various amino acid mutations near active sites of DSRBCB4 dextransucrase from Leuconostoc mesenteroides B-1299CB4 were constructed. A triple amino acid mutation (S642N/E643N/V644S) immediately next to the catalytic D641 (putative transition state stabilizing residue) converted DSRBCB4 enzyme from the synthesis of mainly α-(1→6) dextran to the synthesis of α-(1→6) glucan containing branches of α-(1→3) and α-(1→4) glucosidic linkages. The subsequent introduction of mutation V532P/V535I, located next to the catalytic D530 (nucleophile), resulted in the synthesis of an α-glucan containing increased branched α-(1→4) glucosidic linkages (approximately 11%). The results indicate that mutagenesis can guide glucansucrase toward the synthesis of various oligosaccharides or novel polysaccharides with completely altered linkages without compromising high transglycosylation activity and efficiency.
- Kang, Hee Kyoung,Kimura, Atsuo,Kim, Doman
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experimental part
p. 4148 - 4155
(2011/10/30)
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- Enzymatic synthesis of l-DOPA α-glycosides by reaction with sucrose catalyzed by four different glucansucrases from four strains of Leuconostoc mesenteroides
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Synthesized by reaction of Leuconostoc mesenteroides B-512FMC, B-742CB, B-1299A dextransucrases, and B-1355C alternansucrase with sucrose and l-DOPA α-glycosides were synthesized by reaction of l-DOPA with sucrose, catalyzed by four different glucansucras
- Yoon, Seung-Heon,Fulton, D. Bruce,Robyt, John F.
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experimental part
p. 1730 - 1735
(2010/10/19)
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- Alternansucrase acceptor reactions with D-tagatose and L-glucose
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Alternansucrase (EC 2.4.1.140) is a d-glucansucrase that synthesizes an alternating α-(1→3), (1→6)-linked d-glucan from sucrose. It also synthesizes oligosaccharides via d-glucopyranosyl transfer to various acceptor sugars. Two of the more efficient monosaccharide acceptors are d-tagatose and l-glucose. In the presence of d-tagatose, alternansucrase produced the disaccharide α-d-glucopyranosyl-(1→1)-β-d-tagatopyranose via glucosyl transfer. This disaccharide is analogous to trehalulose. We were unable to isolate a disaccharide product from l-glucose, but the trisaccharide α-d-glucopyranosyl-(1→6)-α-d-glucopyranosyl-(1→4) -l-glucose was isolated and identified. This is analogous to panose, one of the structural units of pullulan, in which the reducing-end d-glucose residue has been replaced by its l-enantiomer. The putative l-glucose disaccharide product, produced by glucoamylase hydrolysis of the trisaccharide, was found to be an acceptor for alternansucrase. The disaccharide, α-d-glucopyranosyl- (1→4)-l-glucose, was a better acceptor than maltose, previously the best known acceptor for alternansucrase. A structure comparison of α-d-glucopyranosyl-(1→4)-l-glucose and maltose was performed through computer modeling to identify common features, which may be important in acceptor affinity by alternansucrase.
- C?té, Gregory L.,Dunlap, Christopher A.,Appell, Michael,Momany, Frank A.
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p. 257 - 262
(2007/10/03)
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- Synthesis of acarbose analogues by transglycosylation reactions of Leuconostoc mesenteroides B-512FMC and B-742CB dextransucrases.
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Two new acarbose analogues were synthesized by the reaction of acarbose with sucrose and dextransucrases from Leuconostoc mesenteroides B-512FMC and B-742CB. The major products for each reaction were subjected to yeast fermentation, and then separated and
- Yoon, Seung-Heon,Robyt, John F
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p. 2427 - 2435
(2007/10/03)
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- NEUE SYNTHESE UND KRISTALLSTRUKTUR DER LEUCROSE
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Boron trifluoride-catalyzed condensation of 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl fluoride (2) with 3,4-di-O-benzoyl-1,2-O-isopropylidene-β-D-fructopyranose (1) gave preferentially the α-D-(1->5)-linked disaccharide 8.Similarly, glycosylation of benzyl 1,3,4-tri-O-benzoyl-β-D-fructopyranoside (4) with 2 gave preponderantly a disaccharide derivative that, after cleavage of benzoyl as well as benzyl groups, afforded leucrose (5-O-α-D-glucopyranosyl-β-D-fructopyranose; 13).This crystallized in the orthorhombic space group P212121 containing four sugar and four water molecules in the unit cell in two positions in the ratio of 4:1.As expected, both the fructopyranose and the glucopyranose rings adopted the 2C5(D) or 4C1(D) chair conformations, respectively.
- Thiem, Joachim,Kleeberg, Matthias,Klaska, Karl-Heinz
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