25193-53-7Relevant articles and documents
Heterologous expression of a thermostable α-glucosidase from Geobacillus sp. Strain HTA-462 by Escherichia coli and its potential application for isomaltose–oligosaccharide synthesis
Zhang, Fan,Wang, Weiyang,Bah, Fatoumata Binta Maci,Song, Chengcheng,Zhou, Yifa,Ji, Li,Yuan, Ye
, (2019/05/02)
Isomaltose–oligosaccharides (IMOs), as food ingredients with prebiotic functionality, can be prepared via enzymatic synthesis using α-glucosidase. In the present study, the α-glucosidase (GSJ) from Geobacillus sp. strain HTA-462 was cloned and expressed in Escherichia coli BL21 (DE3). Recombinant GSJ was purified and biochemically characterized. The optimum temperature condition of the recombinant enzyme was 65 ?C, and the half-life was 84 h at 60 ?C, whereas the enzyme was active over the range of pH 6.0–10.0 with maximal activity at pH 7.0. The α-glucosidase activity in shake flasks reached 107.9 U/mL and using 4-Nitrophenyl β-D-glucopyranoside (pNPG) as substrate, the Km and Vmax values were 2.321 mM and 306.3 U/mg, respectively. The divalent ions Mn2+ and Ca2+ could improve GSJ activity by 32.1% and 13.8%. Moreover, the hydrolysis ability of recombinant α-glucosidase was almost the same as that of the commercial α-glucosidase (Bacillus stearothermophilus). In terms of the transglycosylation reaction, with 30% maltose syrup under the condition of 60 ?C and pH 7.0, IMOs were synthesized with a conversion rate of 37%. These studies lay the basis for the industrial application of recombinant α-glucosidase.
Transglycosylation properties of maltodextrin glucosidase (MalZ) from Escherichia coli and its application for synthesis of a nigerose-containing oligosaccharide
Song, Kyung-Mo,Shim, Jae-Hoon,Park, Jong-Tae,Kim, Sung-Hee,Kim, Young-Wan,Boos, Winfried,Park, Kwan-Hwa
experimental part, p. 87 - 92 (2011/10/18)
The transglycosylation reaction of maltodextrin glucosidase (MalZ) cloned and purified from Escherichia coli K12 was characterized and applied to the synthesis of branched oligosaccharides. Purified MalZ preferentially catalyzed the hydrolysis of maltodextrin, γ-cyclodextrin (CD), and cycloamylose (CA). In addition, when the enzyme was incubated with 5% maltotriose (G3), a series of transfer products were produced. The resulting major transfer products, annotated as T1, T2, and T3, were purified and their structures were determined by TLC, MALDI-TOF/MS, 13C NMR, and enzymatic analysis. T1 was identified as a novel compound, maltosyl α-1,3-maltose, whereas T2 and T3 were determined to be isopanose and maltosyl-α-1,6-maltose, respectively. These results indicated that MalZ transferred sugar moiety mainly to C-3 or C-6-OH of glucose of the acceptor molecule. To obtain highly concentrated transfer products, the enzyme was reacted with 10% liquefied cornstarch, and then glucose and maltose were removed by immobilized yeast. The T1 content of the resulting reaction mixture reached 9.0%. The mixture of T1 containing a nigerose moiety can have an immunopotentiating effect on the human body and may be a potential functional sugar stuff.
COMBINED USE OF DIPEPTIDYL PEPTIDASE IV INHIBITOR COMPOUND AND SWEETENER
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, (2010/01/29)
The present invention provides a novel therapeutic or preventive method, a pharmaceutical composition and use thereof, that exhibit superior anti-obesity effects (body weight-reducing (losing) effects and/or body fat mass-reducing effects). Specifically, the present invention provides a pharmaceutical composition comprising the combination of a dipeptidyl peptidase 4 inhibitor and a sweetener having a GLP-1 secretion-stimulating action, as well as use thereof for the manufacture of a medicament. The present invention also provides a method for treating or preventing obesity, comprising administering an effective amount of (a) a dipeptidyl peptidase 4 inhibitor and (b) a sweetener having a GLP-1 secretion-stimulating action to a patient suffering from symptoms of obesity.
Heterologous expression and biochemical characterization of α-glucosidase from aspergillus niger by pichia pastroris
Chen, Dong-Li,Tong, Xing,Chen, Shang-Wei,Chen, Sheng,Wu, Dan,Fang, Shu-Guang,Wu, Jing,Chen, Jian
experimental part, p. 4819 - 4824 (2011/08/03)
The aglu of Aspergillus niger encodes the pro-protein of α-glucosidase, and the mature form of wild-type enzyme is a heterosubunit protein. In the present study, the cDNA of α-glucosidase was cloned and expressed in Pichia pastoris strain KM71. The activity of recombinant enzyme in a 3 L fermentor reached 2.07 U/mL after 96 h of induction. The recombinant α-glucosidase was able to produce oligoisomaltose. The molecular weight of the recombinant enzyme was estimated to be about 145 kDa by SDS-PAGE, and it reduced to 106 kDa after deglycosylation. The enzymatic activity of recombinant α-glucosidase was not significantly affected by a range of metal ions. The optimum temperature of the enzyme was 60 °C, and it was stable below 50 °C. The enzyme was active over the range of pH 3.0-7.0 with maximal activity at pH 4.5. Using pNPG as substrate, the Km and Vmax values were 0.446 mM and 43.48 U/mg, respectively. These studies provided the basis for the application of recombinant α-glucosidase in the industry of functional oligosaccharides.
Branched alpha-glucan, alpha-glucosyltransferase which forms the glucan, their preparation and uses
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Page/Page column 18-19, (2010/06/11)
The present invention has objects to provide a glucan useful as water-soluble dietary fiber, its preparation and uses. The present invention solves the above objects by providing a branched α-glucan, which is constructed by glucose molecules and characterized by methylation analysis as follows: (1) Ratio of 2,3,6-trimethyl-1,4,5-triacetyl-glucitol to 2,3,4-trimethyl-1,5,6-triacetyl-glucitol is in the range of 1:0.6 to 1:4;(2) Total content of 2,3,6-trimethyl-1,4,5-triacetyl-glucitol and 2,3,4-trimethyl-1,5,6-triacetyl-glucitol is 60% or higher in the partially methylated glucitol acetates;(3) Content of 2,4,6-trimethyl-1,3,5-triacetyl-glucitol is 0.5% or higher but less than 10% in the partially methylated glucitol acetates; and(4) Content of 2,4-dimethyl-1,3,5,6-tetraacetyl-glucitol is 0.5% or higher in the partially methylated glucitol acetates; a novel α-glucosyltransferase which forms the branched α-glucan, processes for producing them, and their uses.
Crystal structure of a 117 kDa glucansucrase fragment provides insight into evolution and product specificity of GH70 enzymes
Vujicic-Zagar, Andreja,Pijning, Tjaard,Kralj, Slavko,Lopez, Cesar A.,Eeuwema, Wieger,Dijkhuizen, Lubbert,Dijkstra, Bauke W.
body text, p. 21406 - 21411 (2011/10/04)
Glucansucrases are large enzymes belonging to glycoside hydrolase family 70, which catalyze the cleavage of sucrose into fructose and glucose, with the concomitant transfer of the glucose residue to a growing α-glucan polymer. Among others, plaque-forming oral bacteria secrete these enzymes to produce α-glucans, which facilitate the adhesion of the bacteria to the tooth enamel. We determined the crystal structure of a fully active, 1,031-residue fragment encompassing the catalytic and C-terminal domains of GTF180 from Lactobacillus reuteri 180, both in the native state, and in complexes with sucrose and maltose. These structures show that the enzyme has an α-amylase-like (β/α) 8-barrel catalytic domain that is circularly permuted compared to the catalytic domains of members of glycoside hydrolase families 13 and 77, which belong to the same GH-H superfamily. In contrast to previous suggestions, the enzyme has only one active site and one nucleophilic residue. Surprisingly, in GTF180 the peptide chain follows a "U"-path, such that four of the five domains are made up from discontiguous N- and C-terminal stretches of the peptide chain. Finally, the structures give insight into the factors that determine the different linkage types in the polymeric product.
Research on the strong transglycosylation activity in Aspergillus niger
Yu, Lan,Zhang, Yun-Kai,Qin, Yong-Ling,Liu, Yu-Yan,Liang, Zhi-Qun
experimental part, p. 749 - 751 (2009/05/09)
Aspergillus niger M-1 strain shows strong transglycosylation activity. A gene of it was introduced into Escherichia coli, and isomalto-oligosaccharides were isolated by a chemical enzymatic method in order to measure the transglycosylation activity.
