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O'Donoghue LT, Murphy EG. Nondairy food applications of whey and milk permeates: Direct and indirect uses. Compr Rev Food Sci Food Saf 2023; 22:2652-2677. [PMID: 37070222 DOI: 10.1111/1541-4337.13157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 03/10/2023] [Accepted: 03/30/2023] [Indexed: 04/19/2023]
Abstract
Permeates are generated in the dairy industry as byproducts from the production of high-protein products (e.g., whey or milk protein isolates and concentrates). Traditionally, permeate was disposed of as waste or used in animal feed, but with the recent move toward a "zero waste" economy, these streams are being recognized for their potential use as ingredients, or as raw materials for the production of value-added products. Permeates can be added directly into foods such as baked goods, meats, and soups, for use as sucrose or sodium replacers, or can be used in the production of prebiotic drinks or sports beverages. In-direct applications generally utilize the lactose present in permeate for the production of higher value lactose derivatives, such as lactic acid, or prebiotic carbohydrates such as lactulose. However, the impurities present, short shelf life, and difficulty handling these streams can present challenges for manufacturers and hinder the efficiency of downstream processes, especially compared to pure lactose solutions. In addition, the majority of these applications are still in the research stage and the economic feasibility of each application still needs to be investigated. This review will discuss the wide variety of nondairy, food-based applications of milk and whey permeates, with particular focus on the advantages and disadvantages associated with each application and the suitability of different permeate types (i.e., milk, acid, or sweet whey).
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Affiliation(s)
| | - Eoin G Murphy
- Teagasc Food Research Centre, Moorepark, Fermoy, Ireland
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2
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Wang M, Wang L, Lyu X, Hua X, Goddard JM, Yang R. Lactulose production from lactose isomerization by chemo-catalysts and enzymes: Current status and future perspectives. Biotechnol Adv 2022; 60:108021. [PMID: 35901861 DOI: 10.1016/j.biotechadv.2022.108021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/02/2022] [Accepted: 07/17/2022] [Indexed: 11/29/2022]
Abstract
Lactulose, a semisynthetic nondigestive disaccharide with versatile applications in the food and pharmaceutical industries, has received increasing interest due to its significant health-promoting effects. Currently, industrial lactulose production is exclusively carried out by chemical isomerization of lactose via the Lobry de Bruyn-Alberda van Ekenstein (LA) rearrangement, and much work has been directed toward improving the conversion efficiency in terms of lactulose yield and purity by using new chemo-catalysts and integrated catalytic-purification systems. Lactulose can also be produced by an enzymatic route offering a potentially greener alternative to chemo-catalysis with fewer side products. Compared to the controlled trans-galactosylation by β-galactosidase, directed isomerization of lactose with high isomerization efficiency catalyzed by the most efficient lactulose-producing enzyme, cellobiose 2-epimerase (CE), has gained much attention in recent decades. To further facilitate the industrial translation of CE-based lactulose biotransformation, numerous studies have been reported on improving biocatalytic performance through enzyme mediated molecular modification. This review summarizes recent developments in the chemical and enzymatic production of lactulose. Related catalytic mechanisms are also highlighted and described in detail. Emerging techniques that aimed at advancing lactulose production, such as the boronate affinity-based technique and molecular biological techniques, are reviewed. Finally, perspectives on challenges and opportunities in lactulose production and purification are also discussed.
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Affiliation(s)
- Mingming Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China; College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong Province 266003, China; Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Lu Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
| | - Xiaomei Lyu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
| | - Xiao Hua
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
| | - Julie M Goddard
- Department of Food Science, Cornell University, Ithaca, NY 14853, USA.
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China.
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Liangfei L, Yafeng Z, Kai X, Zheng X. Identification of a thermostable cellobiose 2-epimerase from Caldicellulosiruptor sp. Rt8.B8 and production of epilactose using Bacillus subtilis. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:85-94. [PMID: 34031874 DOI: 10.1002/jsfa.11333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 05/17/2021] [Accepted: 05/24/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Epilactose, a potential prebiotics, was derived from lactose through enzymatic catalysis. However, production and purification of epilactose are currently difficult due to powerless enzymes and inefficient downstream processing steps. RESULTS The encoding gene of cellobiose 2-epimerase (CE) from Caldicellulosiruptor sp. Rt8.B8 was cloned and expressed in Escherichia coli BL21(DE3). The enzyme was purified and it was suitable for industrial production of epilactose from lactose without by-products, because of high kcat (197.6 s-1 ) and preferable thermostability. The Rt8-CE gene was further expressed in the Bacillus subtilis strain. We successfully produced epilactose from 700 g L-1 lactose in 30.4% yield by using the recombinant Bacillus subtilis whole cells. By screening of a β-galactosidase from Bacillus stearothermophilus (BsGal), a process for separating epilactose and lactose was established, which showed a purity of over 95% in a total yield of 69.2%. In addition, a mixed rare sugar syrup composed of epilactose and d-tagatose was successfully produced from lactose through the co-expression of l-arabinose isomerase and β-galactosidase. CONCLUSION Our study shed light on the efficient production of epilactose using a food-grade host expressing a novel CE enzyme. Moreover, an efficient and low-cost process was attempted to obtain high purity epilactose. In order to improve the utilization of raw materials, the production process of mixed syrup containing epilactose and d-tagatose with prebiotic properties produced from lactose was also established for the first time. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Li Liangfei
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Zhu Yafeng
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Xu Kai
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, China
| | - Xu Zheng
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211816, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China
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Insight into the significant roles of the Trp372 and flexible loop in directing the catalytic direction and substrate specificity in AGE superfamily enzymes. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Chen Q, Xiao Y, Zhang W, Stressler T, Fischer L, Jiang B, Mu W. Computer-aided search for a cold-active cellobiose 2-epimerase. J Dairy Sci 2020; 103:7730-7741. [PMID: 32684457 DOI: 10.3168/jds.2020-18153] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 05/04/2020] [Indexed: 01/06/2023]
Abstract
Cellobiose 2-epimerase (CE) is a promising industrial enzyme that can catalyze bioconversion of lactose to its high-value derivatives, namely epilactose and lactulose. A need exists in the dairy industry to catalyze lactose bioconversions at low temperatures to avoid microbial growth. We focused on the discovery of cold-active CE in this study. A genome mining method based on computational prediction was used to screen the potential genes encoding cold-active enzymes. The CE-encoding gene from Roseburia intestinalis, with a predicted high structural flexibility, was expressed heterologously in Escherichia coli. The catalytic property of the recombinant enzyme was extensively studied. The optimum temperature and pH of the enzyme were 45°C and 7.0, respectively. The specific activity of this enzyme to catalyze conversion of lactose to epilactose was measured to be 77.3 ± 1.6 U/mg. The kinetic parameters, including turnover number (kcat), Michaelis constant (Km), and catalytic efficiency (kcat/Km) using lactose as a substrate were 117.0 ± 7.7 s-1, 429.9 ± 57.3 mM, and 0.27 mM-1s-1, respectively. In situ production of epilactose was carried out at 8°C: 20.9% of 68.4 g/L lactose was converted into epilactose in 4 h using 0.02 mg/mL (1.5 U/mL, measured at 45°C) of recombinant enzyme. The enzyme discovered by this in silico method is suitable for low-temperature applications.
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Affiliation(s)
- Qiuming Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Yaqin Xiao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Wenli Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Timo Stressler
- University of Hohenheim, Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, 70599 Stuttgart, Germany
| | - Lutz Fischer
- University of Hohenheim, Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, 70599 Stuttgart, Germany
| | - Bo Jiang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China.
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Chen Q, Xiao Y, Shakhnovich EI, Zhang W, Mu W. Semi-rational design and molecular dynamics simulations study of the thermostability enhancement of cellobiose 2-epimerases. Int J Biol Macromol 2020; 154:1356-1365. [DOI: 10.1016/j.ijbiomac.2019.11.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 01/19/2023]
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Simulation-guided enzyme discovery: A new microbial source of cellobiose 2-epimerase. Int J Biol Macromol 2019; 139:1002-1008. [PMID: 31401280 DOI: 10.1016/j.ijbiomac.2019.08.075] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/13/2019] [Accepted: 08/07/2019] [Indexed: 11/22/2022]
Abstract
Cellobiose 2-epimerase (CE) is a promising industrial enzyme that can be utilized in the dairy industry. More thermostable CEs from different microorganisms are still needed for a higher lactulose productivity. This study demonstrated the feasibility to use molecular dynamics (MD) simulation as the preliminary computational filter for thermostable enzymes screening. Sequence information of eleven uncharacterized CEs were chosen to be analyzed by MD simulations. The CE from Dictyoglomus thermophilum (Dith-CE) was determined experimentally to be one of the most thermostable CEs with the highest epimerization (160 ± 6.5 U mg-1) and isomerization activities (3.52 ± 0.23 U mg-1) among all the reported CEs. This enzyme shows the highest isomerization activity at 85 °C and pH 7.0. The kinetic parameters (kcat and Km) of isomerization activity of this CE are 3.98 ± 0.3 s-1 and 235.2 ± 11.2 mM, respectively. These results suggest that the CE from Dith-CE is a promising lactulose-producing enzyme.
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Xiao Y, Chen Q, Guang C, Zhang W, Mu W. An overview on biological production of functional lactose derivatives. Appl Microbiol Biotechnol 2019; 103:3683-3691. [DOI: 10.1007/s00253-019-09755-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 03/05/2019] [Accepted: 03/08/2019] [Indexed: 12/30/2022]
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9
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Chen Q, Xiao Y, Zhang W, Zhang T, Jiang B, Stressler T, Fischer L, Mu W. Current research on cellobiose 2-epimerase: Enzymatic properties, mechanistic insights, and potential applications in the dairy industry. Trends Food Sci Technol 2018. [DOI: 10.1016/j.tifs.2018.09.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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10
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Chen Q, Levin R, Zhang W, Zhang T, Jiang B, Stressler T, Fischer L, Mu W. Characterisation of a novel cellobiose 2-epimerase from thermophilic Caldicellulosiruptor obsidiansis for lactulose production. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:3095-3105. [PMID: 27873314 DOI: 10.1002/jsfa.8148] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/17/2016] [Accepted: 11/17/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Lactulose, a bioactive lactose derivative, has been widely used in food and pharmaceutical industries. Isomerisation of lactose to lactulose by cellobiose 2-epimerase (CE) has recently attracted increasing attention, since CE produces lactulose with high yield from lactose as a single substrate. In this study, a new lactulose-producing CE from Caldicellulosiruptor obsidiansis was extensively characterised. RESULTS The recombinant enzyme exhibited maximal activity at pH 7.5 and 70 °C. It displayed high thermostability with Tm of 86.7 °C. The half-life was calculated to be 8.1, 2.8 and 0.6 h at 75, 80, and 85 °C, respectively. When lactose was used as substrate, epilactose was rapidly produced in a short period, and afterwards both epilactose and lactose were steadily isomerised to lactulose, with a final ratio of 35:11:54 for lactose:epilactose:lactulose. When the reverse reaction was investigated using lactulose as substrate, both lactose and epilactose appeared to be steadily produced from the start. CONCLUSION The recombinant CE showed both epimerisation and isomerisation activities against lactose, making it an alternative promising biocatalyst candidate for lactulose production. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Qiuming Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Roman Levin
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- University of Hohenheim, Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, Garbenstr. 25, 70599, Stuttgart, Germany
| | - Wenli Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Tao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Bo Jiang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, 214122, China
| | - Timo Stressler
- University of Hohenheim, Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, Garbenstr. 25, 70599, Stuttgart, Germany
| | - Lutz Fischer
- University of Hohenheim, Institute of Food Science and Biotechnology, Department of Biotechnology and Enzyme Science, Garbenstr. 25, 70599, Stuttgart, Germany
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, 214122, China
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Kuschel B, Seitl I, Glück C, Mu W, Jiang B, Stressler T, Fischer L. Hidden Reaction: Mesophilic Cellobiose 2-Epimerases Produce Lactulose. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:2530-2539. [PMID: 28252294 DOI: 10.1021/acs.jafc.6b05599] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Lactulose (4-O-β-d-galactopyranosyl-d-fructofuranose) is a prebiotic sugar derived from the milk sugar lactose (4-O-β-d-galactopyranosyl-d-glucopyranose). In our study we observed for the first time that known cellobiose 2-epimerases (CEs; EC 5.1.3.11) from mesophilic microorganisms were generally able to catalyze the isomerization reaction of lactose into lactulose. Commonly, CEs catalyze the C2-epimerization of d-glucose and d-mannose moieties at the reducing end of β-1,4-glycosidic-linked oligosaccharides. Thus, epilactose (4-O-β-d-galactopyranosyl-d-mannopyranose) is formed with lactose as substrate. So far, only four CEs, exclusively from thermophilic microorganisms, have been reported to additionally catalyze the isomerization reaction of lactose into lactulose. The specific isomerization activity of the seven CEs in this study ranged between 8.7 ± 0.1 and 1300 ± 37 pkat/mg. The results indicate that very likely all CEs are able to catalyze both the epimerization as well as the isomerization reaction, whereby the latter is performed at a comparatively much lower reaction rate.
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Affiliation(s)
- Beatrice Kuschel
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim , Garbenstrasse 25, D-70599, Stuttgart, Germany
| | - Ines Seitl
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim , Garbenstrasse 25, D-70599, Stuttgart, Germany
| | - Claudia Glück
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim , Garbenstrasse 25, D-70599, Stuttgart, Germany
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University , Wuxi, Jiangsu 214122, China
| | - Bo Jiang
- State Key Laboratory of Food Science and Technology, Jiangnan University , Wuxi, Jiangsu 214122, China
| | - Timo Stressler
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim , Garbenstrasse 25, D-70599, Stuttgart, Germany
| | - Lutz Fischer
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim , Garbenstrasse 25, D-70599, Stuttgart, Germany
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12
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Reaction investigation of lactulose-producing cellobiose 2-epimerases under operational relevant conditions. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcatb.2016.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Kuschel B, Riemer F, Pfost D, Conrad J, Losch C, Claaßen W, Beifuß U, Weiss J, Mu W, Jiang B, Stressler T, Fischer L. Large-scale purification of epilactose using a semi-preparative HPLC system. Eur Food Res Technol 2016. [DOI: 10.1007/s00217-016-2752-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Saburi W. Functions, structures, and applications of cellobiose 2-epimerase and glycoside hydrolase family 130 mannoside phosphorylases. Biosci Biotechnol Biochem 2016; 80:1294-305. [PMID: 27031293 DOI: 10.1080/09168451.2016.1166934] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Carbohydrate isomerases/epimerases are essential in carbohydrate metabolism, and have great potential in industrial carbohydrate conversion. Cellobiose 2-epimerase (CE) reversibly epimerizes the reducing end d-glucose residue of β-(1→4)-linked disaccharides to d-mannose residue. CE shares catalytic machinery with monosaccharide isomerases and epimerases having an (α/α)6-barrel catalytic domain. Two histidine residues act as general acid and base catalysts in the proton abstraction and addition mechanism. β-Mannoside hydrolase and 4-O-β-d-mannosyl-d-glucose phosphorylase (MGP) were found as neighboring genes of CE, meaning that CE is involved in β-mannan metabolism, where it epimerizes β-d-mannopyranosyl-(1→4)-d-mannose to β-d-mannopyranosyl-(1→4)-d-glucose for further phosphorolysis. MGPs form glycoside hydrolase family 130 (GH130) together with other β-mannoside phosphorylases and hydrolases. Structural analysis of GH130 enzymes revealed an unusual catalytic mechanism involving a proton relay and the molecular basis for substrate and reaction specificities. Epilactose, efficiently produced from lactose using CE, has superior physiological functions as a prebiotic oligosaccharide.
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Affiliation(s)
- Wataru Saburi
- a Research Faculty of Agriculture , Hokkaido University , Sapporo , Japan
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Saburi W, Tanaka Y, Muto H, Inoue S, Odaka R, Nishimoto M, Kitaoka M, Mori H. Functional reassignment of Cellvibrio vulgaris EpiA to cellobiose 2-epimerase and an evaluation of the biochemical functions of the 4-O-β-d-mannosyl-d-glucose phosphorylase-like protein, UnkA. Biosci Biotechnol Biochem 2015; 79:969-77. [DOI: 10.1080/09168451.2015.1012146] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
The aerobic soil bacterium Cellvibrio vulgaris has a β-mannan-degradation gene cluster, including unkA, epiA, man5A, and aga27A. Among these genes, epiA has been assigned to encode an epimerase for converting d-mannose to d-glucose, even though the amino acid sequence of EpiA is similar to that of cellobiose 2-epimerases (CEs). UnkA, whose function currently remains unknown, shows a high sequence identity to 4-O-β-d-mannosyl-d-glucose phosphorylase. In this study, we have investigated CE activity of EpiA and the general characteristics of UnkA using recombinant proteins from Escherichia coli. Recombinant EpiA catalyzed the epimerization of the 2-OH group of sugar residue at the reducing end of cellobiose, lactose, and β-(1→4)-mannobiose in a similar manner to other CEs. Furthermore, the reaction efficiency of EpiA for β-(1→4)-mannobiose was 5.5 × 104-fold higher than it was for d-mannose. Recombinant UnkA phosphorolyzed β-d-mannosyl-(1→4)-d-glucose and specifically utilized d-glucose as an acceptor in the reverse reaction, which indicated that UnkA is a typical 4-O-β-d-mannosyl-d-glucose phosphorylase.
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Affiliation(s)
- Wataru Saburi
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Yuka Tanaka
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Hirohiko Muto
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Sota Inoue
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Rei Odaka
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Mamoru Nishimoto
- National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Motomitsu Kitaoka
- National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Haruhide Mori
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
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Krewinkel M, Kaiser J, Merz M, Rentschler E, Kuschel B, Hinrichs J, Fischer L. Novel cellobiose 2-epimerases for the production of epilactose from milk ultrafiltrate containing lactose. J Dairy Sci 2015; 98:3665-78. [DOI: 10.3168/jds.2015-9411] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 03/10/2015] [Indexed: 01/22/2023]
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17
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Chen Q, Zhang W, Zhang T, Jiang B, Mu W. Characterization of an epilactose-producing cellobiose 2-epimerase from Thermoanaerobacterium saccharolyticum. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcatb.2015.03.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Wang M, Yang R, Hua X, Shen Q, Zhang W, Zhao W. Lactulose production from lactose by recombinant cellobiose 2-epimerase in permeabilisedEscherichia colicells. Int J Food Sci Technol 2015. [DOI: 10.1111/ijfs.12776] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Mingming Wang
- State Key Laboratory of Food Science and Technology; Jiangnan University; 214122 Wuxi China
- School of Food Science and Technology; Jiangnan University; 214122 Wuxi China
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology; Jiangnan University; 214122 Wuxi China
- School of Food Science and Technology; Jiangnan University; 214122 Wuxi China
| | - Xiao Hua
- School of Food Science and Technology; Jiangnan University; 214122 Wuxi China
| | - Qiuyun Shen
- School of Food Science and Technology; Jiangnan University; 214122 Wuxi China
| | - Wenbin Zhang
- School of Food Science and Technology; Jiangnan University; 214122 Wuxi China
| | - Wei Zhao
- School of Food Science and Technology; Jiangnan University; 214122 Wuxi China
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Krewinkel M, Gosch M, Rentschler E, Fischer L. Epilactose production by 2 cellobiose 2-epimerases in natural milk. J Dairy Sci 2014; 97:155-61. [DOI: 10.3168/jds.2013-7389] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 09/14/2013] [Indexed: 11/19/2022]
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Fujiwara T, Saburi W, Matsui H, Mori H, Yao M. Structural insights into the epimerization of β-1,4-linked oligosaccharides catalyzed by cellobiose 2-epimerase, the sole enzyme epimerizing non-anomeric hydroxyl groups of unmodified sugars. J Biol Chem 2013; 289:3405-15. [PMID: 24362032 DOI: 10.1074/jbc.m113.531251] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellobiose 2-epimerase (CE) reversibly converts d-glucose residues into d-mannose residues at the reducing end of unmodified β1,4-linked oligosaccharides, including β-1,4-mannobiose, cellobiose, and lactose. CE is responsible for conversion of β1,4-mannobiose to 4-O-β-d-mannosyl-d-glucose in mannan metabolism. However, the detailed catalytic mechanism of CE is unclear due to the lack of structural data in complex with ligands. We determined the crystal structures of halothermophile Rhodothermus marinus CE (RmCE) in complex with substrates/products or intermediate analogs, and its apo form. The structures in complex with the substrates/products indicated that the residues in the β5-β6 loop as well as those in the inner six helices form the catalytic site. Trp-322 and Trp-385 interact with reducing and non-reducing end parts of these ligands, respectively, by stacking interactions. The architecture of the catalytic site also provided insights into the mechanism of reversible epimerization. His-259 abstracts the H2 proton of the d-mannose residue at the reducing end, and consistently forms the cis-enediol intermediate by facilitated depolarization of the 2-OH group mediated by hydrogen bonding interaction with His-200. His-390 subsequently donates the proton to the C2 atom of the intermediate to form a d-glucose residue. The reverse reaction is mediated by these three histidines with the inverse roles of acid/base catalysts. The conformation of cellobiitol demonstrated that the deprotonation/reprotonation step is coupled with rotation of the C2-C3 bond of the open form of the ligand. Moreover, it is postulated that His-390 is closely related to ring opening/closure by transferring a proton between the O5 and O1 atoms of the ligand.
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Affiliation(s)
- Takaaki Fujiwara
- From the Faculty of Advanced Life Science, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo 060-0810 and
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Fujiwara T, Saburi W, Inoue S, Mori H, Matsui H, Tanaka I, Yao M. Crystal structure of Ruminococcus albus cellobiose 2-epimerase: structural insights into epimerization of unmodified sugar. FEBS Lett 2013; 587:840-6. [PMID: 23462136 DOI: 10.1016/j.febslet.2013.02.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 01/31/2013] [Accepted: 02/01/2013] [Indexed: 10/27/2022]
Abstract
Enzymatic epimerization is an important modification for carbohydrates to acquire diverse functions attributable to their stereoisomers. Cellobiose 2-epimerase (CE) catalyzes interconversion between d-glucose and d-mannose residues at the reducing end of β-1,4-linked oligosaccharides. Here, we solved the structure of Ruminococcus albus CE (RaCE). The structure of RaCE showed strong similarity to those of N-acetyl-D-glucosamine 2-epimerase and aldose-ketose isomerase YihS with a high degree of conservation of residues around the catalytic center, although sequence identity between them is low. Based on structural comparison, we found that His184 is required for RaCE activity as the third histidine added to two essential histidines in other sugar epimerases/isomerases. This finding was confirmed by mutagenesis, suggesting a new catalytic mechanism for CE involving three histidines.
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Affiliation(s)
- Takaaki Fujiwara
- Graduate School of Life Science, Hokkaido University, Kita-ku, Sapporo, Japan
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