Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as Biocatalyst
Cellobiose 2-epimerase from Rhodothermus marinus (RmCE) reversibly converts a glucose residue to a mannose residue at the reducing end of β-1,4-linked oligosaccharides. In this study, the monosaccharide specificity of RmCE has been mapped and the synthesis of d-talose from d-galactose was d...
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MDPI AG
2018-10-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/23/10/2519 |
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| author | Stevie Van Overtveldt Ophelia Gevaert Martijn Cherlet Koen Beerens Tom Desmet |
| author_facet | Stevie Van Overtveldt Ophelia Gevaert Martijn Cherlet Koen Beerens Tom Desmet |
| author_sort | Stevie Van Overtveldt |
| collection | DOAJ |
| description | Cellobiose 2-epimerase from Rhodothermus marinus (RmCE) reversibly converts a glucose residue to a mannose residue at the reducing end of β-1,4-linked oligosaccharides. In this study, the monosaccharide specificity of RmCE has been mapped and the synthesis of d-talose from d-galactose was discovered, a reaction not yet known to occur in nature. Moreover, the conversion is industrially relevant, as talose and its derivatives have been reported to possess important antimicrobial and anti-inflammatory properties. As the enzyme also catalyzes the keto-aldo isomerization of galactose to tagatose as a minor side reaction, the purity of talose was found to decrease over time. After process optimization, 23 g/L of talose could be obtained with a product purity of 86% and a yield of 8.5% (starting from 4 g (24 mmol) of galactose). However, higher purities and concentrations can be reached by decreasing and increasing the reaction time, respectively. In addition, two engineering attempts have also been performed. First, a mutant library of RmCE was created to try and increase the activity on monosaccharide substrates. Next, two residues from RmCE were introduced in the cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE) (S99M/Q371F), increasing the kcat twofold. |
| first_indexed | 2024-12-12T14:31:49Z |
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| id | doaj.art-70f27437da544f83bb46d6fa1cf46b70 |
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| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-12T14:31:49Z |
| publishDate | 2018-10-01 |
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| series | Molecules |
| spelling | doaj.art-70f27437da544f83bb46d6fa1cf46b702022-12-22T00:21:30ZengMDPI AGMolecules1420-30492018-10-012310251910.3390/molecules23102519molecules23102519Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as BiocatalystStevie Van Overtveldt0Ophelia Gevaert1Martijn Cherlet2Koen Beerens3Tom Desmet4Centre for Synthetic Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, BelgiumCentre for Synthetic Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, BelgiumCentre for Synthetic Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, BelgiumCentre for Synthetic Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, BelgiumCentre for Synthetic Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, BelgiumCellobiose 2-epimerase from Rhodothermus marinus (RmCE) reversibly converts a glucose residue to a mannose residue at the reducing end of β-1,4-linked oligosaccharides. In this study, the monosaccharide specificity of RmCE has been mapped and the synthesis of d-talose from d-galactose was discovered, a reaction not yet known to occur in nature. Moreover, the conversion is industrially relevant, as talose and its derivatives have been reported to possess important antimicrobial and anti-inflammatory properties. As the enzyme also catalyzes the keto-aldo isomerization of galactose to tagatose as a minor side reaction, the purity of talose was found to decrease over time. After process optimization, 23 g/L of talose could be obtained with a product purity of 86% and a yield of 8.5% (starting from 4 g (24 mmol) of galactose). However, higher purities and concentrations can be reached by decreasing and increasing the reaction time, respectively. In addition, two engineering attempts have also been performed. First, a mutant library of RmCE was created to try and increase the activity on monosaccharide substrates. Next, two residues from RmCE were introduced in the cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE) (S99M/Q371F), increasing the kcat twofold.http://www.mdpi.com/1420-3049/23/10/2519biocatalysiscellobiose 2-epimeraserare sugarstaloseenzyme engineering |
| spellingShingle | Stevie Van Overtveldt Ophelia Gevaert Martijn Cherlet Koen Beerens Tom Desmet Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as Biocatalyst Molecules biocatalysis cellobiose 2-epimerase rare sugars talose enzyme engineering |
| title | Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as Biocatalyst |
| title_full | Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as Biocatalyst |
| title_fullStr | Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as Biocatalyst |
| title_full_unstemmed | Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as Biocatalyst |
| title_short | Converting Galactose into the Rare Sugar Talose with Cellobiose 2-Epimerase as Biocatalyst |
| title_sort | converting galactose into the rare sugar talose with cellobiose 2 epimerase as biocatalyst |
| topic | biocatalysis cellobiose 2-epimerase rare sugars talose enzyme engineering |
| url | http://www.mdpi.com/1420-3049/23/10/2519 |
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