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Improvement of the Transglycosylation Efficiency of a Lacto-N-Biosidase from Bifidobacterium bifidum by Protein Engineering. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app112311493] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The lacto-N-biosidase LnbB from Bifidobacterium bifidum JCM 1254 was engineered to improve its negligible transglycosylation efficiency with the purpose of enzymatically synthesizing lacto-N-tetraose (LNT; Gal-β1,3-GlcNAc-β1,3-Gal-β1,4-Glc) in one enzymatic step. LNT is a prebiotic human milk oligosaccharide in itself and constitutes the structural core of a range of more complex human milk oligosaccharides as well. Thirteen different LnbB variants were expressed and screened for transglycosylation activity by monitoring transglycosylation product formation using lacto-N-biose 1,2-oxazoline as donor substrate and lactose as acceptor substrate. LNT was the major reaction product, yet careful reaction analysis revealed the formation of three additional LNT isomers, which we identified to have a β1,2-linkage, a β1,6-linkage, and a 1,1-linkage, respectively, between lacto-N-biose (Gal-β1,3-GlcNAc) and lactose. Considering both maximal transglycosylation yield and regioselectivity as well as minimal product hydrolysis, the best variant was LnbB W394H, closely followed by W465H and Y419N. A high transglycosylation yield was also obtained with W394F, yet the substitution of W394 and W465 of the subsite −1 hydrophobic platform in the enzyme with His dramatically impaired the undesirable product hydrolysis as compared to substitution with Phe; the effect was most pronounced for W465. Using p-nitrophenyl-β-lacto-N-bioside as donor substrate manifested W394 as an important target position. The optimization of the substrate concentrations confirmed that high initial substrate concentration and high acceptor-to-donor ratio both favor transglycosylation.
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Abstract
β-N-acetylhexosaminidases (EC 3.2.1.52) are retaining hydrolases of glycoside hydrolase family 20 (GH20). These enzymes catalyze hydrolysis of terminal, non-reducing N-acetylhexosamine residues, notably N-acetylglucosamine or N-acetylgalactosamine, in N-acetyl-β-D-hexosaminides. In nature, bacterial β-N-acetylhexosaminidases are mainly involved in cell wall peptidoglycan synthesis, analogously, fungal β-N-acetylhexosaminidases act on cell wall chitin. The enzymes work via a distinct substrate-assisted mechanism that utilizes the 2-acetamido group as nucleophile. Curiously, the β-N-acetylhexosaminidases possess an inherent trans-glycosylation ability which is potentially useful for biocatalytic synthesis of functional carbohydrates, including biomimetic synthesis of human milk oligosaccharides and other glycan-functionalized compounds. In this review, we summarize the reaction engineering approaches (donor substrate activation, additives, and reaction conditions) that have proven useful for enhancing trans-glycosylation activity of GH20 β-N-acetylhexosaminidases. We provide comprehensive overviews of reported synthesis reactions with GH20 enzymes, including tables that list the specific enzyme used, donor and acceptor substrates, reaction conditions, and details of the products and yields obtained. We also describe the active site traits and mutations that appear to favor trans-glycosylation activity of GH20 β-N-acetylhexosaminidases. Finally, we discuss novel protein engineering strategies and suggest potential “hotspots” for mutations to promote trans-glycosylation activity in GH20 for efficient synthesis of specific functional carbohydrates and other glyco-engineered products.
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Bankova E, Bakalova N, Petrova S, Kolev D. Enzymatic Synthesis of Oligosaccharides and Alkylglycosides in Water-Organic Media Via Transglycosylation of Lactose. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.1080/13102818.2006.10817387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Zeng X, Sun Y, Ye H, Liu J, Uzawa H. Synthesis of p-nitrophenyl sulfated disaccharides with β-d-(6-sulfo)-GlcNAc units using β-N-acetylhexosaminidase from Aspergillus oryzae in a transglycosylation reaction. Biotechnol Lett 2007; 29:1105-10. [PMID: 17492477 DOI: 10.1007/s10529-007-9366-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 02/27/2007] [Accepted: 03/01/2007] [Indexed: 10/23/2022]
Abstract
When alpha-D-GlcNAc-OC(6)H(4)NO(2) -p and beta-D-(6-sulfo)-GlcNAc-OC(6)H(4)NO(2)-p (2) were used as substrates, beta-N-acetylhexosaminidase from Aspergillus oryzae transferred the beta-D-(6-sulfo)-GlcNAc(unit from 2 to alpha-D-GlcNAc-OC(6)H(4)NO(2) -p to afford beta-D-(6-sulfo)-GlcNAc-(1-->4)-alpha-D-GlcNAc-OC(6)H(4)NO(2)-p (3) in a yield of 94% based on the amount of donor, 2, added. beta-D-(6-sulfo)-GlcNAc-(1-->4)-alpha-D-Glc-OC(6)H(4)NO(2)-p (4) was obtained with alpha-D-Glc-OC(6)H(4)NO(2) -p as acceptor in a similar manner. With a reaction mixture of 2 and beta-D-GlcNAc-OC(6)H(4)NO(2)-p (1) in a molar ratio of 6:1, the enzyme mediated the transfer of beta-D-GlcNAc from 1 to 2, affording disaccharide beta-D-GlcNAc-(1-->4)-beta-(6-sulfo)-D-GlcNAc-OC(6)H(4)NO(2)-p (5) in a yield of 13% based on the amount of 1 added.
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Affiliation(s)
- Xiaoxiong Zeng
- Department of Biotechnology, College of Food Science and Technology, Nanjing Agricultural University, Weigang 1, Nanjing, PR China.
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Zeng X, Sun Y, Uzawa H. Efficient enzymatic synthesis of 4-methylumbelliferyl N-acetyllactosaminide and 4-methylumbelliferyl sialyl N-acetyllactosaminides employing beta-D-galactosidase and sialyltransferases. Biotechnol Lett 2005; 27:1461-5. [PMID: 16231217 DOI: 10.1007/s10529-005-1310-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Accepted: 07/12/2005] [Indexed: 10/25/2022]
Abstract
4-Methylumbelliferyl N-acetyllactosaminide and 4-methylumbelliferyl sialyl N-acetyllactosaminides, which are used for the assay of sialytransferase, neuraminidase and fucosyltransferase, were synthesized, respectively, by the beta-D: -galactosidase from Bacillus circulans and by a recombinant rat alpha2,3-(N)-sialyltransferase or rat liver alpha2,6-(N)-sialyltransferase with CMP-N-acetylneuraminic acid as donor.
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Affiliation(s)
- Xiaoxiong Zeng
- Department of Biotechnology, College of Food Science and Technology, Nanjing Agricultural University, 210095, Weigang, Nanjing, Jiangsu, PR China.
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Lakshmanan T, Loganathan D. Enzymatic synthesis of N-glycoprotein linkage region disaccharide mimetics using β-N-acetylhexosaminidases from Aspergillus oryzae and Vigna radiata. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.tetasy.2004.11.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Hart JB, Kröger L, Falshaw A, Falshaw R, Farkas E, Thiem J, Win AL. Enzyme-catalysed synthesis of galactosylated 1d- and 1l-chiro-inositol, 1d-pinitol, myo-inositol and selected derivatives using the β-galactosidase from the thermophile Thermoanaerobacter sp. strain TP6-B1. Carbohydr Res 2004; 339:1857-71. [PMID: 15261579 DOI: 10.1016/j.carres.2004.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2004] [Accepted: 05/08/2004] [Indexed: 11/18/2022]
Abstract
The products from the enzymatic beta-D-galactopyranosylation of 1D-chiro-inositol, 1D-pinitol, 1D-3-O-allyl-4-O-methyl-chiro-inositol, 1D-3,4-di-O-methyl-chiro-inositol, 1L-chiro-inositol and myo-inositol in combined yields ranging from 46% to 64% have been obtained using the beta-galactosidase isolated from an anaerobic extreme thermophile, Thermoanaerobacter sp. strain TP6-B1 and p-nitrophenyl beta-D-galactopyranoside as the donor. Analysis of the products from these reactions reveals information about the acceptor preferences of the enzyme.
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Affiliation(s)
- Joanne B Hart
- Carbohydrate Chemistry Team, Industrial Research Ltd, PO Box 31-310, Lower Hutt, New Zealand.
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Nieder V, Kutzer M, Kren V, Gallego RG, Kamerling JP, Elling L. Screening and characterization of β-N-acetylhexosaminidases for the synthesis of nucleotide-activated disaccharides. Enzyme Microb Technol 2004. [DOI: 10.1016/j.enzmictec.2003.11.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Synthesis of oligosaccharides as potential novel food components and upscaled enzymatic reaction employing the β-galactosidase from bovine testes. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.01.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Weignerová L, Vavrusková P, Pisvejcová A, Thiem J, Kren V. Fungal beta-N-acetylhexosaminidases with high beta-N-acetylgalactosaminidase activity and their use for synthesis of beta-GalNAc-containing oligosaccharides. Carbohydr Res 2003; 338:1003-8. [PMID: 12681926 DOI: 10.1016/s0008-6215(03)00044-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
About 60 fungal strains were tested for production of extracellular beta-N-acetylhexosaminidases. A unique beta-N-acetylhexosaminidase with the beta-GalNAc-ase/beta-GlcNAc-ase ratio of 2.3-2.8 was found in the culture filtrates of some strains of Penicillium oxalicum. Addition of 20% (w/v) MgSO(4) increased the beta-GalNAc-ase/beta-GlcNAc-ase ratio to the value of 3.35. Cultivation conditions influence this ratio as well. beta-N-Acetylhexosaminidases from P. oxalicum CCF 2430 and Aspergillus oryzae CCF 1066 considerably differing in the GalNAc-ase activity were used for the synthesis of the following structures beta-D-GalpNAc-(1-->4)-D-GlcpNAc, beta-D-GalpNAc-(1-->6)-D-GlcpNAc, beta-D-GalpNAc-(1-->6)-D-GalpNAc, beta-D-GalpNAc-(1-->4)-alpha-D-GlcpNAcOAll and beta-D-GalpNAc-(1-->6)-beta-D-Galp-(1-->4)-alpha-D-GlcpNAcOAll to demonstrate the application of these new enzymes.
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Affiliation(s)
- Lenka Weignerová
- Laboratory of Biotransformation, Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, Prague 4, CZ 142 20, Czech Republic
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Langlois V, Parisot J, Bonnet V, Rabiller C. Transfer activity of bovine liver β-glucuronidase: synthesis of disaccharides containing a β-d-glucopyranuronate unit. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00590-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Parisot J, Ghochikyan A, Langlois V, Sakanyan V, Rabiller C. Exopolygalacturonate lyase from Thermotoga maritima: cloning, characterization and organic synthesis application. Carbohydr Res 2002; 337:1427-33. [PMID: 12204603 DOI: 10.1016/s0008-6215(02)00175-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A new exopolygalacturonate lyase (Pel) gene of the hyperthermophilic bacterium Thermotoga maritima was cloned and overexpressed in Escherichia coli cells. A 42 kDa monomeric Pel was shown to undergo N-terminal processing by cleavage at a putative site between alanine and serine residues. The enzyme catalyzes selectively a beta-4,5 elimination at the third galacturonic unit from the reducing end of polygalacturonic acid by producing (4-deoxy-alpha-L-threo-hex-4-enopyranosyluronic acid)-(1-->4)-(alpha-D-galactopyranosyluronic acid)-(1-->4)-alpha-D-galactopyranuronic acid (3) with a 60% yield. The optimum activity of the enzyme was detected at pH 9.5 and T> or=95 degrees C. The highly thermostable enzyme constitutes a useful catalyst for a simplified synthesis of 4,5-unsaturated trigalacturonic acid 3, a trisaccharide which is extremely difficult to obtain via chemical synthesis.
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Affiliation(s)
- Judicaël Parisot
- Unité de Recherches en Biocatalyse (FRE-CNRS 2230), Faculté des Sciences et des Techniques, 2, rue de la Houssinière, BP 92208, F-44322, Nantes, France
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Spangenberg P, André C, Langlois V, Dion M, Rabiller C. Alpha-galactosyl fluoride in transfer reactions mediated by the green coffee beans alpha-galactosidase in ice. Carbohydr Res 2002; 337:221-8. [PMID: 11844492 DOI: 10.1016/s0008-6215(01)00309-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We show that the yields in saccharide synthesis by tranglycosylation with alpha-galactosidase from green coffee beans can be greatly enhanced when working in ice. Thus, methyl alpha-D-galactopyranosyl-(1-->3)-alpha-D-galactopyranoside (3a) produced by reaction of alpha-D-galactopyranosyl fluoride 1 with methyl alpha-D-galactopyranoside (2) is obtained with 51% yield in ice while only 29% is synthesized at 37 degrees C. This result, already previously found by others with proteases and by us with a beta-galactosidase appears to be a general property of hydrolases.
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Affiliation(s)
- Petra Spangenberg
- Unité de Recherches en Biocatalyse (unité CNRS 2230), Faculté des Sciences et des Techniques, 2, rue de la Houssinière, BP 92208, F-44322, Nantes, France
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Murata T, Kosugi M, Nakamura T, Urashima T, Usui T. Enzymatic synthesis of sulfated disaccharides using beta-D-galactosidase-catalyzed transglycosylation. Biosci Biotechnol Biochem 2001; 65:2456-64. [PMID: 11791719 DOI: 10.1271/bbb.65.2456] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have established a unique enzymatic approach for obtaining sulfated disaccharides using Bacillus circulans beta-D-galactosidase-catalyzed 6-sulfo galactosylation. When 4-methyl umbelliferyl 6-sulfo beta-D-galactopyranoside (S6Gal beta-4MU) was used as a donor, the enzyme induced transfer of 6-sulfo galactosyl residue to GlcNAc acceptor. As a result, the desired compound 6'-sulfo N-acetyllactosamine (S6Gal beta1-4GlcNAc) and its positional isomer 6'-sulfo N-acetylisolactosamine (S6Gal beta1-6GlcNAc) were observed by HPAEC-PAD, in 49% total yield based on the donor added, and in a molar ratio of 1:3.5. With a glucose acceptor, the regioselectivity was substantially changed and S6Gal beta1-2Glc was mainly produced along with beta-(1-1)alpha, beta-(1-3), beta-(1-6) isomers in 74% total yield. When methyl alpha-D-glucopyranoside (Glc alpha-OMe) was an acceptor, the enzyme also formed mainly S6Gal beta1-2Glc alpha-OMe with its beta-(1-6)-linked isomer in 41% total yield based on the donor added. In both cases, it led to the predominant formation of beta-(1-2)-linked disaccharides. In contrast, with the corresponding methyl beta-D-glucopyranoside (Glc beta-OMe) acceptor, S6Gal beta1-3Glc beta-OMe and S6Gal beta1-6Glc beta-OMe were formed in a low total yield of 12%. These results indicate that the regioselectivity and efficiency on the beta-D-galactosidase-mediated transfer reaction significantly depend on the anomeric configuration in the glucosyl acceptors.
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Affiliation(s)
- T Murata
- Department of Applied Biological Chemistry, Shizuoka University, Japan.
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André C, Spangenberg P, Gentil E, Rabiller C. In situ 19F NMR spectroscopy study of enzymatic transglycosylation reactions using α-d-aldohexopyranosyl fluorides as donors and acceptors. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0957-4166(01)00120-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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17
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Koeller KM, Wong CH. Synthesis of complex carbohydrates and glycoconjugates: enzyme-based and programmable one-pot strategies. Chem Rev 2000; 100:4465-94. [PMID: 11749355 DOI: 10.1021/cr990297n] [Citation(s) in RCA: 347] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K M Koeller
- Department of Chemistry, The Scripps Research Institute and Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, California 92037
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Spangenberg P, André C, Dion M, Rabiller C, Mattes R. Comparative study of new alpha-galactosidases in transglycosylation reactions. Carbohydr Res 2000; 329:65-73. [PMID: 11086687 DOI: 10.1016/s0008-6215(00)00170-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have studied the potential of several newly cloned alpha-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 alpha-galactosidase from Thermus brockianus (strain IT360). Two other non-thermophilic alpha-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 alpha-D-galactopyranosyl-(1--> 6)-alpha-D-galactopyranoside and methyl alpha-D-galactopyranosyl-(1--> 6)-alpha-D-galactopyranoside, which were obtained in 54% (Aga B) and 20% (Aga T) yields, respectively.
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Affiliation(s)
- P Spangenberg
- Unité de Recherches en Biocatalyse (Unité CNRS 2230), Faculte des Sciences et des Techniques, Nantes, France
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Scigelova M, Crout DH. Microbial β-N-acetylhexosaminidases and their biotechnological applications. Enzyme Microb Technol 1999. [DOI: 10.1016/s0141-0229(98)00171-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Vetere A, Paoletti S. Separation and characterization of three beta-galactosidases from Bacillus circulans. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1380:223-31. [PMID: 9565691 DOI: 10.1016/s0304-4165(97)00145-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Crude preparation of Bacillus circulans beta-galactosidase is known to have a good transglycolytic activity. Two isoforms of the enzyme have been described so far in the literature. Aiming at separating these two forms to assess their relative contribution to the regioselectivity of transglycosylation, we observed the presence of a third isoform never described before. This paper deals with the isolation procedures of the three enzymes and a re-consideration of their properties. The estimated molecular weight for the isoforms were 212 kDa (I), 145 kDa (II) and 86 kDa (III), respectively. Kinetic parameters were determined towards the hydrolysis of o-nitrophenyl-beta-d-galactopyranoside (ONPG) and lactose. For ONPG the following values of Km were found: 3.6, 5.0 and 3.3 mM for I, II and III, respectively, whereas for lactose the values were 3.7, 2.94 and 2.71 mM, respectively.
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Affiliation(s)
- A Vetere
- Department of Biochemistry, Biophysics and Macromolecular Chemistry, University of Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy.
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Crout DH, Vic G. Glycosidases and glycosyl transferases in glycoside and oligosaccharide synthesis. Curr Opin Chem Biol 1998; 2:98-111. [PMID: 9667913 DOI: 10.1016/s1367-5931(98)80041-0] [Citation(s) in RCA: 201] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Remarakable advances in glycobiology in recent years have stimulated a resurgence of interest in carbohydrate chemistry. The challenge of producing the complex glycosides and oligosaccharides needed for research in glycobiology has led to the development of enzymatic methods that are now firmly established as part of the synthetic repertoire of the carbohydrate chemist.
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Affiliation(s)
- D H Crout
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
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Singh S, Scigelova M, Critchley P, Crout DH. Trisaccharide synthesis by glycosyl transfer from p-nitrophenyl beta-D-N-acetylgalactosaminide on to disaccharide acceptors catalysed by the beta-N-acetylhexosaminidase from Aspergillus oryzae. Carbohydr Res 1997; 305:363-70. [PMID: 9648256 DOI: 10.1016/s0008-6215(97)10030-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The beta-N-acetylhexosaminidase from Aspergillus oryzae catalysed the transfer of beta-D-N-acetylgalactosaminyl residues from p-nitrophenyl beta-D-N-acetylglucosaminide on to disaccharide acceptors consisting of thioethyl glycosides of alpha-D-Glc-(1-->4)-beta-D-Glc, beta-D-Glc-(1-->4)-beta-D-Glc and beta-D-Glc-(1-->6)-beta-D-Glc. The principle of 'anomeric control' was exemplified by the results which showed that an alpha-linkage between the units of the acceptor favoured exclusively the formation of a new (1-->4)-linkage, whereas the beta-configuration in the acceptor led to a mixture of (1-->4)- and (1-->3)-linked products, as observed for simple glycosides of monosaccharide acceptors. With the thioethyl beta-lactoside as acceptor, beta-D-Gal-(1-->6)-beta-D-Gal-(1-->4)-beta-D-GlcSEt was formed, owing to the action of residual beta-D-galactosidase activity in the N-acetylhexosaminidase on the thioethyl beta-lactoside acting as both donor and acceptor.
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Affiliation(s)
- S Singh
- Department of Chemistry, University of Warwick, Coventry, UK
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Finch P, Yoon JH. The effects of organic solvents on the synthesis of galactose disaccharides using β-galactosidases. Carbohydr Res 1997. [DOI: 10.1016/s0008-6215(97)00182-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chiffoleau-Giraud V, Spangenberg P, Rabiller C. β-Galactosidase transferase activity in ice and use of vinyl-β-d-galactoside as donor. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0957-4166(97)00194-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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