- A recombinant levansucrase from Bacillus licheniformis 8-37-0-1 catalyzes versatile transfructosylation reactions
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This work disclosed the broad transglycosylation capability of the levansucrase from Bacillus licheniformis 8-37-0-1 for the first time. The levansucrase was firstly purified from the strain 8-37-0-1 and found to be a monomer of ～51 kDa with KETQDYKKSY as the N-terminus. Then, the gene encoding the enzyme was cloned and it contained an ORF of 1449 nucleotides, encoding a 482 amino-acid protein with a predicted 29 amino-acid signal peptide. The deduced mature protein without the signal showed the same N-terminus to the purified enzyme. The mature enzyme was subsequently expressed in Escherichia coli. The recombinant enzyme showed similar biochemical properties to the native one. It produced maximal yield of 7.1 mg/mL levan (Mr 9.6 × 106) from 0.8 M sucrose (pH 6.5) at 40 °C for 24 h in vitro. When using sucrose as the donor, the enzyme displayed a wide range of acceptor specificity and was able to transfer fructosyl to a series of sugar acceptors including hexose, pentose, β- or α-disaccharides, along with the difficult branched alcohols that have not been investigated before. Chemical structures of the resultant products were analyzed by MS and NMR spectra.
- Lu, Lili,Fu, Feng,Zhao, Renfei,Jin, Lan,He, Chunjuan,Xu, Li,Xiao, Min
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p. 1503 - 1510
(2015/01/06)
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- Gluco-oligomers initially formed by the reuteransucrase enzyme of Lactobacillus reuteri 121 incubated with sucrose and malto-oligosaccharides
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The probiotic bacterium Lactobacillus reuteri 121 produces a complex, branched (1 → 4, 1 → 6)-α-D-glucan as extracellular polysaccharide (reuteran) from sucrose (Suc), using a single glucansucrase/glucosyltransferase (GTFA) enzyme (reuteransucrase). To gain insight into the reaction/product specificity of the GTFA enzyme and the mechanism of reuteran formation, incubations with Suc and/or a series of malto-oligosaccharides (MOSs) (degree of polymerization (DP2-DP6)) were followed in time. The structures of the initially formed products, isolated via high-performance anion-exchange chromatography, were analyzed by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry and 1D/2D 1H/13C NMR spectroscopy. Incubations with Suc only, acting as both donor and acceptor, resulted in elongation of Suc with glucose (Glc) units via alternating (α1 → 4) and (α1 → 6) linkages, yielding linear gluco-oligosaccharides up to at least DP ~ 12. Simultaneously with the ensemble of oligosaccharides, polymeric material was formed early on, suggesting that alternan fragments longer than DP ~ 12 have higher affinity with the GTFA enzyme and are quickly extended, yielding high-molecular-mass branched reuteran (4 × 107 Da). MOSs (DP2-DP6) in the absence of Suc turned out to be poor substrates. Incubations of GTFA with Suc plus MOSs as substrates resulted in preferential elongation of MOSs (acceptors) with Glc units from Suc (donor). This apparently reflects the higher affinity of GTFA for MOSs compared with Suc. In accordance with the GTFA specificity, most prominent products were oligosaccharides with an (α1 → 4)/(α1 → 6) alternating structure. The Author 2013. Published by Oxford University Press.
- Dobruchowska, Justyna M,Meng, Xiangfeng,Leemhuis, Hans,Gerwig, Gerrit J,Dijkhuizen, Lubbert,Kamerling, Johannis P.
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p. 1084 - 1096
(2013/08/23)
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- Method for synthesizing oligosaccharides and glycosylation
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The invention relates to an enzymatic method for synthesizing oligosaccharides, whereby one saccharide group of a sucrose analogue each is transferred onto an acceptor molecule, for example for glycosylating a hydroxyl compound, a saccharide, peptide, or a drug. According to the inventive method, an enzymatic synthesis of β-D-fructofuranosyl-a-D-aldopyranoside is carried out in a first step, and in a second step one of the saccharide groups is enzymatically transferred onto the acceptor molecule.
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Page/Page column 7
(2009/04/24)
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- First direct glycosylation of unprotected nonreducing mono- and disaccharides
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The first single-step random-glycosylation methodology for fully unprotected glycosyl acceptors is reported by random glycosylation leading to all possible regioisomers. For such systems conventional glycosylation methods such as Koenigs-Knorr glycosylation, Schmidt's trichloroacetimidate glycosylation and reactions employing glycosyl fluoride donors fail entirely. Starting from unprotected nonreducing saccharides, the glycosylation of β-glucosylated and β-galactosylated monosaccharides (Glc, Gal), symmetric disaccharides (e.g. α,α-trehaloses) as well as unsymmetric disaccharides (e.g. sucrose) were studied. The influence of base type and concentration were examined. Several libraries of di- and trisaccharides were generated. All regioisomers were formed in approximately equal proportions, and their partial separation was achieved by flash column chromatography. Even though it appears that overall yields are lower when comparing to classical protecting-group chemistry, this synthetic effort may be superior especially for access to higher saccharides. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Steinmann, Andreas,Thimm, Julian,Thiem, Joachim
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p. 5506 - 5513
(2008/09/17)
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- CRYSTALLINE LACTOSUCROSE OR MOLASSES-CONTAINING CRYSTAL HAVING THE SAME CONTAINED THEREIN, AND USE THEREOF
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The present invention establishes a crystalline lactosucrose and provides a process for producing the crystalline lactosucrose or a syrup containing crystalline lactosucrose. Further, the present invention has its object to provide a composition, for example, a food or drink, a cosmetic, a drug or the like containing the crystalline lactosucrose. That is, the present invention provides the crystalline lactosucrose or the syrup containing crystalline lactosucrose, the process for producing the crystalline lactosucrose or the syrup containing crystalline lactosucrose, characterized by crystallizing a crystalline lactosucrose from a solution containing lactosucrose and collecting the crystalline lactosucrose, and the use thereof.
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Page/Page column 5-6
(2008/06/13)
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- Synthesis of maltooligosyl fructofuranosides catalyzed by immobilized cyclodextrin glucosyltransferase using starch as donor
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Cyclodextrin glucosyltransferase (CGTase) from Thermoanaerobacter sp. was covalently immobilized on Eupergit C and used for the synthesis of maltooligosyl fructofuranosides employing soluble starch as donor and sucrose as acceptor. Using a weight ratio starch-sucrose of 1:2, the conversion of starch into acceptor products catalyzed by soluble and immobilized CGTases was higher than 80% in 48 h. Under these conditions, the reaction was selective for the formation of maltosyl fructofuranoside.
- Martín, M. Teresa,Cruces, M. Angeles,Alcalde, Miguel,Plou, Francisco J.,Bernabé, Manuel,Ballesteros, Antonio
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p. 529 - 534
(2007/10/03)
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