- Chemical and enzymatic synthesis of glycoconjugates 5: One-pot regioselective synthesis of bioactive galactobiosides using a clonezyme(TM) thermophilic glycosidase library
-
Enzymatic synthesis of galactobiosides using a versatile CLONEZYME(TM) thermostable glycosidase library was studied. One-pot transglycosylation reactions were demonstrated to synthesize β(1→4), β(1→6), and α(1→6) disaccharide sequences with high regiosele
- Li, Jun,Robertson, Dan E.,Short, Jay M.,Wang, Peng George
-
-
Read Online
- Aspergillus nidulans α-galactosidase of glycoside hydrolase family 36 catalyses the formation of α-galacto-oligosaccharides by transglycosylation
-
The α-galactosidase from Aspergillus nidulans (AglC) belongs to a phylogenetic cluster containing eukaryotic α-galactosidases and -galacto-oligosaccharide synthases of glycoside hydrolase family 36 (GH36). The recombinant AglC, produced in high yield (0.65 g·L-1 culture) as His-tag fusion in Escherichia coli, catalysed efficient transglycosylation with α-(1→6) regioselectivity from 40 mm 4-nitrophenol -d-galactopyranoside, melibiose or raffinose, resulting in a 37-74% yield of 4-nitrophenol α-d-Galp-(1→6) α-d-Galp, α-d-Galp- (1→6) α- d-Galp-(1→6) α-d-Glcp and α-d-Galp- (1→6) α- d-Galp-(1→6) α-d-Glcp-(1→2) α-d-Fruf (stachyose), respectively. Furthermore, among 10 monosaccharide acceptor candidates (400 mm) and the donor 4-nitrophenol -d-galactopyranoside (40 mm), -(1→6) linked galactodisaccharides were also obtained with galactose, glucose and mannose in high yields of 39-58%. AglC did not transglycosylate monosaccharides without the 6-hydroxymethyl group, i.e. xylose, l-arabinose, l-fucose and l-rhamnose, or with axial 3-OH, i.e. gulose, allose, altrose and l-rhamnose. Structural modelling using Thermotoga maritima GH36 -galactosidase as the template and superimposition of melibiose from the complex with human GH27 α-galactosidase supported that recognition at subsite +1 in AglC presumably requires a hydrogen bond between 3-OH and Trp358 and a hydrophobic environment around the C-6 hydroxymethyl group. In addition, successful transglycosylation of eight of 10 disaccharides (400 mm), except xylobiose and arabinobiose, indicated broad specificity for interaction with the +2 subsite. AglC thus transferred -galactosyl to 6-OH of the terminal residue in the -linked melibiose, maltose, trehalose, sucrose and turanose in 6-46% yield and the -linked lactose, lactulose and cellobiose in 28-38% yield. The product structures were identified using NMR and ESI-MS and five of the 13 identified products were novel, i.e. α-d-Galp-(1→6) α-d-Manp; α-d-Galp-(1→6) α- d-Glcp-(1→4) α-d-Glcp; α-d-Galp-(1→6) α- d-Galp-(1→4) α-d-Fruf; α-d-Galp-(1→6) α-d-Glcp-(1→1) α-d-Glcp; and α-d-Galp-(1→6) α- d-Glcp-(1→3) α-d-Fruf.
- Nakai, Hiroyuki,Baumann, Martin J.,Petersen, Bent O.,Westphal, Yvonne,Hachem, Maher Abou,Dilokpimol, Adiphol,Duus, Jens .,Schols, Henk A.,Svensson, Birte
-
-
Read Online
- Semi-rational approach for converting a GH36 α-glycosidase into an α-transglycosidase
-
A large number of retaining glycosidases catalyze both hydrolysis and transglycosylation reactions. In order to use them as catalysts for oligosaccharide synthesis, the balance between these two competing reactions has to be shifted toward transglycosylat
- Teze, David,Daligault, Franck,Ferrières, Vincent,Sanejouand, Yves-Henri,Tellier, Charles
-
-
Read Online
- Characterization of properties and transglycosylation abilities of recombinant α-galactosidase from cold-adapted marine bacterium pseudoalteromonas KMM 701 and its C494N and D451A mutants
-
A novel wild-type recombinant cold-active α-D-galactosidase (α-PsGal) from the cold-adapted marine bacterium Pseudoalteromonas sp. KMM 701, and its mutants D451A and C494N, were studied in terms of their structural, physicochemical, and catalytic properties. Homology models of the three-dimensional α-PsGal structure, its active center, and complexes with D-galactose were constructed for identification of functionally important amino acid residues in the active site of the enzyme, using the crystal structure of the α-galactosidase from Lactobacillus acidophilus as a template. The circular dichroism spectra of the wild α-PsGal and mutant C494N were approximately identical. The C494N mutation decreased the efficiency of retaining the affinity of the enzyme to standard p-nitrophenyl-α-galactopiranoside (pNP-α-Gal). Thin-layer chromatography, matrix-assisted laser desorption/ionization mass spectrometry, and nuclear magnetic resonance spectroscopy methods were used to identify transglycosylation products in reaction mixtures. α-PsGal possessed a narrow acceptor specificity. Fructose, xylose, fucose, and glucose were inactive as acceptors in the transglycosylation reaction. α-PsGal synthesized -α(1→6)- and -α(1→4)-linked galactobiosides from melibiose as well as -α(1→6)- and -α(1→3)-linked p-nitrophenyl-digalactosides (Gal2-pNP) from pNP-α-Gal. The D451A mutation in the active center completely inactivated the enzyme. However, the substitution of C494N discontinued the Gal-α(1→3)-Gal-pNP synthesis and increased the Gal-α(1→4)-Gal yield compared to Gal-α(1→6)-Gal-pNP.
- Bakunina, Irina,Slepchenko, Lubov,Anastyuk, Stanislav,Isakov, Vladimir,Likhatskaya, Galina,Kim, Natalya,Tekutyeva, Liudmila,Son, Oksana,Balabanova, Larissa
-
-
Read Online
- Preparation of α-galactooligoglycosides by cell walls from Cryptococcus laurentii using a novel α-galactosyl donor
-
The cell walls of an acapsular strain of the yeast Cryptococcus laurentii catalyze the regioselective formation of α-galactooligosaccharides through self-condensation of 4-nitrophenyl α-D-galactopyranoside and of a novel activated α-galactosyl donor 2,2,2-trifluoroethyl α-D-galactopyranoside. The latter substance can be easily prepared by several methods and is highly soluble in water and therefore can be used in higher initial concentrations suppressing secondary product hydrolysis. The preparative reaction catalyzed by cell walls provided 17.4% and 2% of corresponding 2,2,2-trifluoroethyl galactobioside and galactotrioside, respectively, while the reaction with 4-nitrophenyl α-D-galactopyranoside provided the corresponding 4-nitrophenyl galactobioside and galactotrioside in 6.6 and 2.5% yields, respectively. The reactions proceeded with strict α-(1 → 6)-regioselectivity.
- Mastihuba, Vladimír,Mastihubová, Mária,Belák, Miroslav,Dudíková, Jana,Potocká, Elena Karni?ová,Petru?, Ladislav
-
p. 1089 - 1094
(2017/10/05)
-
- α-Galactobiosyl units: Thermodynamics and kinetics of their formation by transglycosylations catalysed by the GH36 α-galactosidase from Thermotoga maritima
-
Broad regioselectivity of α-galactosidase from Thermotoga maritima (TmGal36A) is a limiting factor for application of the enzyme in the directed synthesis of oligogalactosides. However, this property can be used as a convenient tool in studies of thermodynamics of a glycosidic bond. Here, a novel approach to energy difference estimation is suggested. Both transglycosylation and hydrolysis of three types of galactosidic linkages were investigated using total kinetics of formation and hydrolysis of pNP-galactobiosides catalysed by monomeric glycoside hydrolase family 36 α-galactosidase from T. maritima, a retaining exo-acting glycoside hydrolase. We have estimated transition state free energy differences between the 1,2- and 1,3-linkage (ΔΔG?0 values were equal 5.34 ± 0.85 kJ/mol) and between 1,6-linkage and 1,3-linkage (ΔΔG?0 = 1.46 ± 0.23 kJ/mol) in pNP-galactobiosides over the course of the reaction catalysed by TmGal36A. Using the free energy difference for formation and hydrolysis of glycosidic linkages (ΔΔG?F - ΔΔG?H), we found that the 1,2-linkage was 2.93 ± 0.47 kJ/mol higher in free energy than the 1,3-linkage, and the 1,6-linkage 4.44 ± 0.71 kJ/mol lower.
- Borisova, Anna S.,Ivanen, Dina R.,Bobrov, Kirill S.,Eneyskaya, Elena V.,Rychkov, Georgy N.,Sandgren, Mats,Kulminskaya, Anna A.,Sinnott, Michael L.,Shabalin, Konstantin A.
-
supporting information
p. 115 - 121
(2015/02/19)
-
- α-Galactobiosyl units: Thermodynamics and kinetics of their formation by transglycosylations catalysed by the GH36 α-galactosidase from Thermotoga maritima
-
Broad regioselectivity of α-galactosidase from Thermotoga maritima (TmGal36A) is a limiting factor for application of the enzyme in the directed synthesis of oligogalactosides. However, this property can be used as a convenient tool in studies of thermodynamics of a glycosidic bond. Here, a novel approach to energy difference estimation is suggested. Both transglycosylation and hydrolysis of three types of galactosidic linkages were investigated using total kinetics of formation and hydrolysis of pNP-galactobiosides catalysed by monomeric glycoside hydrolase family 36 α-galactosidase from T. maritima, a retaining exo-acting glycoside hydrolase. We have estimated transition state free energy differences between the 1,2- and 1,3-linkage (ΔΔG?0 values were equal 5.34 ± 0.85 kJ/mol) and between 1,6-linkage and 1,3-linkage (ΔΔG?0 = 1.46 ± 0.23 kJ/mol) in pNP-galactobiosides over the course of the reaction catalysed by TmGal36A. Using the free energy difference for formation and hydrolysis of glycosidic linkages (ΔΔG?F - ΔΔG?H), we found that the 1,2-linkage was 2.93 ± 0.47 kJ/mol higher in free energy than the 1,3-linkage, and the 1,6-linkage 4.44 ± 0.71 kJ/mol lower.
- Borisova, Anna S.,Ivanen, Dina R.,Bobrov, Kirill S.,Eneyskaya, Elena V.,Rychkov, Georgy N.,Sandgren, Mats,Kulminskaya, Anna A.,Sinnott, Michael L.,Shabalin, Konstantin A.
-
p. 115 - 121
(2015/02/18)
-
- α-Galactosyl fluoride in transfer reactions mediated by the green coffee beans α-galactosidase in ice
-
We show that the yields in saccharide synthesis by tranglycosylation with α-galactosidase from green coffee beans can be greatly enhanced when working in ice. Thus, methyl α-D-galactopyranosyl-(1 → 3)-α-D-galactopyranoside (3a) produced by reaction of α-D-galactopyranosyl fluoride 1 with methyl α-D-galactopyranoside (2) is obtained with 51% yield in ice while only 29% is synthesized at 37°C. This result, already previously found by others with proteases and by us with a β-galactosidase appears to be a general property of hydrolases.
- Spangenberg, Petra,Andre, Corinne,Langlois, Virginie,Dion, Michel,Rabiller, Claude
-
p. 221 - 228
(2007/10/03)
-
- Comparative study of new α-galactosidases in transglycosylation reactions
-
We have studied the potential of several newly cloned α-galactosidases to catalyze the regioselective synthesis of disaccharides using 4-nitrophenylgalactoside as a donor. The kinetics of the reactions were followed by in situ NMR spectroscopy. The following thermophilic enzymes have been tested: Aga A and an isoenzyme Aga B obtained from the strain KVE39 and Aga 285 from the strain IT285 of Bacillus stearothermophilus; Aga T is an α-galactosidase from Thermus brockianus (strain IT360). Two other non-thermophilic α-galactosidases have also been evaluated: Aga 1 (Streptococcus mutans, strain Ingbritt) and Raf A (Escherichia coli, strain D1021). For all of the enzymes studied, high regioselectivity was observed leading to two (1 → 6)-disaccharides: 4-nitrophenyl α-D-galactopyranosyl-(1 → 6)-α-D-galactopyranoside and methyl α-D-galactopyranosyl-(1 → 6)-α-D-galactopyranoside, which were obtained in 54% (Aga B) and 20% (Aga T) yields, respectively. (C) 2000 Elsevier Science Ltd.
- Spangenberg, Petra,Andre, Corinne,Dion, Michel,Rabiller, Claude,Mattes, Ralf
-
-
- Transglycosylation activity of α-D-galactosidase from Trichoderma reesei. An investigation of the active site
-
The transglycosylation reaction catalyzed by α-D-galactosidase from the mycelial fungus Trichoderma reesei was studied using p-nitrophenyl α-D- galactopyranoside (PNPG). An aliphatic alcohol or the substrate itself can be an acceptor of the galactose residue in this reaction. The transglycosylation products were identified as alkyl galactosides in the case of alcohols or as galactobioside and galactotrioside in the case of PNPG. The transglycosylation rates follow a first-order equation with respect to the alcohol concentrations except for methanol. Affinities of some substrates were estimated from their K(i) values in the reaction of the enzyme with PNPG. Transglycosylation of the substrate suggests a model for the enzyme active center. It is proposed that the active center includes two galactose- binding sites and a hydrophobic site.
- Eneyskaya, Elena V.,Golubev, Alexander M.,Kachurin, Anatoly M.,Savel'ev, Andrew N.,Neustroev, Kirill N.
-
-
- Enzymatic properties of α-D-galactosidase from Trichoderma reesei
-
The kinetics of hydrolysis of a number of natural and synthetic substrates [melibiose, raffinose, stachyose, methyl α-D-galactopyranoside, and p-nitrophenyl α-D-galactopyranoside (PNPG)], catalyzed by α-D-galactosidase from the fungus Trichoderma reesei, has been studied. A number of N-acyl-α-D-galactopyranosylamines, which are competitive inhibitors of α-D-galactosidase, have been synthesized, and the K(I) values for these compounds have been obtained. The inhibiting properties of the competitive inhibitors of D-galactose, 1,5-anhydro-D-galactitol, and 2-deoxygalactose have been compared, and reasons for differences in K(I) values between these compounds have been discussed. It has been shown that α-D-galactosidase exhibits transglycosylating activity; the main product of transglycosylation in the reaction with PNPG is p-nitrophenyl 6-O-α-D-galactopyranosyl-α-D-galactopyranoside. The hydrolysis inhibition in the presence of a substrate has been shown to correlate with the substrate transglycosylation. Data of steady-state kinetics together with data of presteady-state kinetics obtained by the stop-flow method suggest that an intermediate galactosyl-enzyme complex is formed in the reaction and is of particular importance in the processes under study. A minimal kinetic scheme describing the experimental data obtained is proposed.
- Savel'ev, Andrew N.,Ibatyllin, Farid M.,Eneyskaya, Elena V.,Kachurin, Anatoly M.,Neustroev, Kirill N.
-
p. 261 - 273
(2007/10/03)
-