23745-85-9Relevant articles and documents
Orthogonal Active-Site Labels for Mixed-Linkage endo-β-Glucanases
Jain, Namrata,Tamura, Kazune,Déjean, Guillaume,Van Petegem, Filip,Brumer, Harry
, p. 1968 - 1984 (2021/05/26)
Small molecule irreversible inhibitors are valuable tools for determining catalytically important active-site residues and revealing key details of the specificity, structure, and function of glycoside hydrolases (GHs). β-glucans that contain backbone β(1,3) linkages are widespread in nature, e.g., mixed-linkage β(1,3)/β(1,4)-glucans in the cell walls of higher plants and β(1,3)glucans in yeasts and algae. Commensurate with this ubiquity, a large diversity of mixed-linkage endoglucanases (MLGases, EC 3.2.1.73) and endo-β(1,3)-glucanases (laminarinases, EC 3.2.1.39 and EC 3.2.1.6) have evolved to specifically hydrolyze these polysaccharides, respectively, in environmental niches including the human gut. To facilitate biochemical and structural analysis of these GHs, with a focus on MLGases, we present here the facile chemo-enzymatic synthesis of a library of active-site-directed enzyme inhibitors based on mixed-linkage oligosaccharide scaffolds and N-bromoacetylglycosylamine or 2-fluoro-2-deoxyglycoside warheads. The effectiveness and irreversibility of these inhibitors were tested with exemplar MLGases and an endo-β(1,3)-glucanase. Notably, determination of inhibitor-bound crystal structures of a human-gut microbial MLGase from Glycoside Hydrolase Family 16 revealed.
A novel two-step synthesis of α-linked mannobioses based on an acid-assisted reverse hydrolysis reaction
Ajisaka, Katsumi,Yagura, Misato,Miyazaki, Tatsuo
experimental part, p. 147 - 150 (2012/03/10)
Instead of an enzyme-assisted reverse hydrolysis reaction for the synthesis of manno-oligosaccharides, we propose here a versatile new approach. By Fischer type glycosylation, a d-mannose solution of extremely high concentration (approximately 83% (w/w)) was incubated at 60 °C for 65 h in 0.5 M HCl. After dilution and neutralization, the small amount of formed β-linked oligosaccharides was hydrolyzed by β-mannosidase. The yields of α-d-Manp-(1→2)-d-Manp (7.9%), α-d-Manp-(1→3)-d-Manp (7.9%), and α-d-Manp-(1→6)-d-Manp (29.1%) isolated by an activated carbon column chromatography were almost identical to those of the enzymatic reaction, but the yield of α-d-Manp-(1→3)-d-Manp increased enormously by the present method.
Production of galacto-oligosaccharides by the β-galactosidase from kluyveromyces lactis: Comparative analysis of permeabilized cells versus soluble enzyme
Rodriguez-Colinas, Barbara,De Abreu, Miguel A.,Fernandez-Arrojo, Lucia,De Beer, Roseri,Poveda, Ana,Jimenez-Barbero, Jesus,Haltrich, Dietmar,Ballesteros Olmo, Antonio O.,Fernandez-Lobato, Maria,Plou, Francisco J.
experimental part, p. 10477 - 10484 (2012/07/17)
The transgalactosylation activity of Kluyveromyces lactis cells was studied in detail. Cells were permeabilized with ethanol and further lyophilized to facilitate the transit of substrates and products. The resulting biocatalyst was assayed for the synthesis of galacto-oligosaccharides (GOS) and compared with two soluble β-galactosidases from K. lactis (Lactozym 3000 L HP G and Maxilact LGX 5000). Using 400 g/L lactose, the maximum GOS yield, measured by HPAEC-PAD analysis, was 177 g/L (44% w/w of total carbohydrates). The major products synthesized were the disaccharides 6-galactobiose [Gal-β(1?6)-Gal] and allolactose [Gal-β(1?6)-Glc], as well as the trisaccharide 6-galactosyl-lactose [Gal-β(1?6)-Gal-β(1?4)-Glc], which was characterized by MS and 2D NMR. Structural characterization of another synthesized disaccharide, Gal-β(1?3)-Glc, was carried out. GOS yield obtained with soluble β-galactosidases was slightly lower (160 g/L for Lactozym 3000 L HP G and 154 g/L for Maxilact LGX 5000); however, the typical profile ith a maximum GOS concentration followed by partial hydrolysis of the newly formed oligosaccharides was not observed with the soluble enzymes. Results were correlated with the higher stability of β-galactosidase when permeabilized whole cells were used.
